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 concludes that, by not fully briefing the instrument approach, the captain missed an opportunity to prepare himself, the first officer, and the flight engineer for the relatively complex localizer-only approach and failed to provide the first officer and flight engineer with adequate guidance about monitoring the approach; therefore, the captain's approach briefing was inadequate.

2.4.1.2 Expectation of a Visual Approach and Role of the Guam Airport Familiarization Video

The Safety Board notes that, when the captain flew to Guam about 1 month before the accident, he executed a routine ILS approach to runway 6L in good visibility, with a scattered cumulous buildup. Further, the most current ATIS information available to the accident flight crew indicated that visual conditions (scattered cloud decks and 7-mile visibility) existed at the airport. Korean Air's Guam airport familiarization video, which the captain and first officer had viewed in July 1997, noted that weather conditions in Guam allowed visual approaches most of the year and that, even though IMC is likely during the rainy season from June to November, "you [the pilot] will be guided from over Apra Harbor to the localizer. You will then perform a visual approach...." Thus, the captain may have assumed that conditions for the flight 801 approach would be similar to those he experienced about 1 month earlier. The captain's anticipation of a visual approach probably became a strong expectation after the flight crew's early visual sighting of Guam. Although the captain would likely have recognized the possibility of flight through clouds as the airplane descended from its cruise altitude, he may have assumed that the visual approach slope indicator (VASI) system would be in sight after the flight was vectored onto final approach by the CERAP controller. The VASI system would have provided visual guidance for a constant angle of descent that safely cleared obstacles.

As previously discussed, the captain's landing briefing included references to his expectation of visual conditions at the airport as well as an abbreviated and inadequate briefing for the localizer-only approach. The Safety Board concludes that the captain's expectation of a visual approach was a factor in his incomplete briefing of the localizer approach. The Board is aware that it is a common practice among air carrier pilots to abbreviate the briefing for a backup instrument approach when a visual approach is expected. Although there may be little benefit to fully briefing a backup instrument approach in daylight conditions when no appreciable possibility of encountering IMC exists, the Safety Board concludes that, for flights conducted at night or when there is any possibility that IMC may be encountered, the failure to fully brief an available backup instrument approach compromises safety. Therefore, the Safety Board believes that the FAA should require principal operations inspectors (POI) assigned to U.S. air carriers to ensure that air carrier pilots conduct a full briefing for the instrument approach (if available) intended to back up a visual approach conducted at night or when IMC may be encountered.

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 The Safety Board notes that, although Guam was not a designated special airport requiring special training or familiarization by flight crews, Korean Air encouraged its flight crews to view the airport familiarization video. However, the Guam familiarization video gave only a generalized description of the topography of the island of Guam. Although the video mentioned some of the obstacles near the approach course, it did not specifically state that the UNZ VOR was located on a hill, the DME was not colocated with the localizer, or the final approach segment was over hilly or mountainous terrain.

Even though the airport familiarization video accurately identified some landmarks and advised pilots not to fly over a residential area and a Naval hospital (for noise abatement), the Safety Board also notes with concern that the video contained no discussion of factors that made operations into Guam challenging, such as the high terrain along the approach course or in the vicinity of the airport. Further, the presentation did not describe the complexity of the Guam nonprecision approaches, including the multiple step-down fixes, the use of two separate navigation facilities (the localizer and the VOR), and the countdown/count up DME procedure.

The Safety Board concludes that the Korean Air airport familiarization video for Guam, by emphasizing the visual aspects of the approach, fostered the expectation by company flight crews of a visual approach and, by not emphasizing the terrain hazards and offset DME factors, did not adequately prepare flight crews for the range of potential challenges associated with operations into Guam. Thus, the Safety Board believes that the KCAB should require Korean Air to revise its video presentation for Guam to emphasize that instrument approaches should also be expected and describe the complexity of such approaches and the significant terrain along the approach courses and in the vicinity of the airport.

The Safety Board addressed the issue of the classification of special airports and approaches to certain airports in connection with its investigation of the October 19, 1996, accident involving Delta Air Lines flight 554, an MD-88, at LaGuardia Airport in New York. On August 25, 1997, the Board issued Safety Recommendations A-97-92 through -94, asking the FAA to develop and publish "specific criteria and conditions" for the classification of special airports (including special runways and/or special approaches) and use these criteria to evaluate all airports and "update special airport publications." On November 13, 1997, the FAA responded that it was revising Advisory Circular (AC) 121.445, "Pilot-in-Command Qualifications for Special Area/Routes and Airports," and that the revision would address the issues discussed in the safety recommendations. On August 17, 1998, the Board classified Safety Recommendations A-97-92 through -94 "Open--Acceptable Response" pending completion of the AC. The Board recognizes that the FAA's eventual evaluation of Guam against the newly developed criteria might result in its classification as a special airport. The Safety Board further recognizes that, because the captain flew into Guam and viewed the Guam airport familiarization video during July 1997, he would have been authorized to conduct the accident flight even if Guam had been classified as a special airport.

Nonetheless, the Safety Board concludes that the challenges associated with operations to Guam International Airport support its immediate consideration as a special

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 airport requiring special pilot qualifications. Therefore, the Safety Board believes that the FAA should consider designating Guam International Airport as a special airport requiring special pilot qualifications.

2.4.1.3 Possible Explanations for the Approach Conducted 2.4.1.3.1 Confusion About Status of Glideslope

Despite several indications that the flight crew was aware that the glideslope was inoperative, in the last 2½ minutes of the flight (beginning shortly after the airplane was established on the approach), the CVR recorded a series of conflicting flight crew comments concerning the operational status of the glideslope. About 0139:55, the flight engineer asked, "is the glideslope working?" The captain responded, "yes, yes it's working." About 0139:58, an unidentified voice in the cockpit stated, "check the glideslope if working?" One second later, an unidentified voice in the cockpit stated, "why is it working?" About 0140:00, the first officer responded, "not useable." About 0140:22, an unidentified voice in the cockpit stated, "glideslope is incorrect," followed by the captain's statement, "since today's glideslope condition is not good, we need to maintain one thousand four hundred forty [feet]." However, about 0141:46, after the airplane crossed the GUQQY outer marker (1.6 DME from the VOR), the captain again stated, "isn't glideslope working?"

The Safety Board considered whether the flight crew might have misinterpreted some cockpit instrumentation indications as a valid glideslope capture signal. During the localizer approach into Guam, both pilots' HSIs would have appeared centered; the captain's would have captured the localizer, and the first officer's would have captured the VOR radial. With VOR/LOC selected, the localizer captured, and the pitch commands set to VERT SPEED (the most likely setting), the captain's FD command bars would have shown some vertical and horizontal movement, similar to an FD that was responding to a captured localizer and glideslope. However, the raw data glideslope needles on the attitude director indicator (ADI) and HSI would not have been affected by the VERT SPEED setting; therefore, the captain's ADI and HSI glideslope needles should have been covered by "off" flags. Further, there would have been no glideslope capture annunciator on the GS bar of the FMA on top of the captain's and first officer's instrument panels.

The Safety Board also considered whether the flight crewmembers might have observed intermittent movement of the glideslope needles during the approach, thereby creating or adding to their confusion about the glideslope. An FAA navigation expert testified at the Safety Board's public hearing that spurious radio signals could cause a sporadic or intermittent glideslope indicator deviation in the absence of a valid glideslope signal. However, he stated that the glideslope off flag would still appear on the HSI and ADI glideslope needles and that, when the off flag appears, any movement of the glideslope needle should be considered unreliable. Postaccident testing by Korean Air and the KCAB confirmed that an airplane's glideslope receiver could be affected by spurious

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 radio signals when no valid glideslope signal was being transmitted. The tests demonstrated that spurious signals could cause movement of the glideslope needle and that, when the receiver was subjected to a steady signal, retraction of the off flag was also possible. However, the Safety Board notes that these tests were conducted with an airplane on the ground and that the airplane's navigational receiver was subjected to extreme signal modulations transmitted very near the airplane's antenna. These conditions are not likely to be encountered by an airplane on an actual instrument approach.

The Safety Board also notes that the flight crew of a Boeing 727 reported glideslope anomalies on August 5, 1997, while executing the localizer-only approach to runway 6L at Guam. (The purpose of the flight was to test a newly installed GPS.) However, the captain of the 727 stated that he thought the glideslope anomaly might have been caused by the GPS wiring installation. Further, the first officer stated that he and the captain "never thought twice" about the glideslope indications because they knew that the glideslope was inoperative. The Board's investigation into the 727's maintenance history indicated that, in the weeks after the test flight, several cockpit navigational displays, including the first officer's HSI and ADI, were repeatedly removed and replaced by maintenance personnel because of anomaly reports written up by flight crews. The maintenance documents indicated that the cockpit display problems were the result of integrating the new GPS with the existing cockpit displays.

Although it is possible that spurious radio signals caused some erratic movement of the glideslope needles on the accident captain's HSI and ADI, it is unlikely that the accident airplane's navigation receivers could have been subjected to a steady spurious signal of a duration that would have resulted in a continuous glideslope needle activation and flag retraction over a period of minutes and several miles of aircraft motion. Thus, the presence of the off flags over the glideslope needles at some times and the absence of FMA glideslope capture indicators on the captain's and first officer's instrument panels should have been sufficient to convince the flight 801 flight crew to disregard the glideslope indications. Even if the flight crewmembers did see a continuous glideslope needle activation and flag retraction, it would not have been prudent or reasonable for them to rely on a glideslope signal of any sort when the glideslope had been reported to be unusable. (Korean Air officials stated that flight crews were trained not to use navigational aids, including glideslopes, that were reported to be unreliable or unusable). Therefore, the Safety Board concludes that, although the captain apparently became confused about the glideslope's status, the flight crew had sufficient information to be aware that the glideslope was unusable for vertical guidance and should have ignored any glideslope indications while executing the nonprecision localizer-only approach.

The Safety Board notes that, when a glideslope signal is not generated by the transmitter (resulting in an open frequency channel), an airborne glideslope receiver will continue to seek a glideslope signal, although navigation receiver filters are designed to block most spurious radio signals. The postaccident testing conducted by Korean Air and

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 the KCAB involved the glideslope receiver; however, the Safety Board concludes that navigation receivers, including glideslope receivers, may be susceptible to spurious radio signals. Therefore, the Safety Board believes that the FAA should disseminate information to pilots, through the Aeronautical Information Manual, about the possibility of momentary erroneous indications on cockpit displays when the primary signal generator for a ground-based navigational transmitter (for example, a glideslope, VOR, or nondirectional beacon [NDB] transmitter) is inoperative. Further, this information should reiterate to pilots that they should disregard any navigation indication, regardless of its apparent validity, if the particular transmitter was identified as unusable or inoperative.

2.4.1.3.2 Confusion About Location of DME

About 0140:37, when the airplane was at 2,400 feet msl and descending at 1,000 feet per minute, the captain stated, "since today's glideslope condition is not good, we need to maintain one thousand fourteen hundred forty [feet]. please set it." This statement suggests that the captain was attempting to comply with the restrictions of the localizeronly approach and believed that he had passed the GUQQY step-down fix. However, the CVR recorded no discussion between the captain and the first officer about DME values or their position in relation to the next step-down fix, the VOR, or the airport.

The Safety Board considered whether the flight crew might have confused the configuration of the runway 6L localizer approach with one in which the DME is located on the airport. A review of the flight crew's training records showed that the nonprecision approaches incorporating DME provided to the flight crew during training and check rides had the DME located on the airport. A countdown/count up DME procedure, which is rarely encountered on a localizer procedure, was not included in any of the Korean Air simulator training scenarios. If the flight crewmembers had the misconception that the DME information referred to the distance from the airport, they might have believed that the airplane was much closer to the airport than it actually was (the DME was located 3.3 nm southwest of the airport) and that the airplane was well above the minimum altitudes for the intermediate step-down fixes and thus ready to descend directly to the MDA. If the captain had this misconception, it could explain why he flew the airplane and commanded altitude selections as though he believed he was at or above the altitude constraint for each navigational fix along the approach. If the other flight crewmembers shared this misconception, it could explain why they failed to challenge the captain's premature descents below 2,000 and 1,440 feet.

However, this scenario suggests strongly that the captain was not noting the definitions of the navigational fixes on the approach chart, which were clearly defined as DME values. Thus, the Safety Board concludes that the captain may have mistakenly believed that the airplane was closer to the airport than its actual position; however, if the captain conducted the flight's descent on this basis, he did so in disregard of the DME fix definitions shown on the approach chart.

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 2.4.1.4 Summary of Captain's Performance on the Approach

As the approach progressed without encountering the visual conditions the captain had anticipated, the captain likely experienced increased stress because of his inadequate preparation for the nonprecision approach, which made the approach increasingly challenging. CVR and FDR data indicated that, shortly after the captain appeared to become preoccupied with the status of the glideslope, he allowed the airplane to descend prematurely below the required intermediate altitudes of the approach. Thus, the captain may have failed to track the airplane's position on the approach because he believed that he would regain visual conditions, the airplane was receiving a valid glideslope signal, and/or the airplane was closer to the airport than its actual position. Regardless of the reason for failing to track the airplane's position, the captain conducted the approach without properly cross-referencing the positional fixes defined by the VOR and DME with the airplane's altitude. Therefore, the Safety Board concludes that, as a result of his confusion and preoccupation with the status of the glideslope, failure to properly cross-check the airplane's position and altitude with the information on the approach chart, and continuing expectation of a visual approach, the captain lost awareness of flight 801's position on the ILS localizer-only approach to runway 6L at Guam International Airport and improperly descended below the intermediate approach altitudes of 2,000 and 1,440 feet, which was causal to the accident.

CVR evidence indicated that the flight crew seemed confused about, and did not react to, a series of audible ground proximity warning system (GPWS) alerts during the final approach. The first audible GPWS callout occurred about 0141:42, with the "one thousand [feet]" altitude call. A second GPWS callout of "five hundred [feet]" occurred about 0142:00 (when the airplane was descending through about 1,200 feet msl), to which the flight engineer responded in astonishment, "eh?" However, FDR data indicated that no change in the airplane's descent profile followed, and the CVR indicated that the flight engineer continued to complete the landing checklist. Similarly, no flight crew discussion followed the GPWS callout of "minimums" about 0142:14, and the first officer dismissed a GPWS "sink rate" alert 3 seconds later by stating "sink rate okay." About 0142:19, the flight engineer called "two hundred [feet]," followed immediately by the first officer saying "let's make a missed approach." The flight engineer immediately responded "not in sight," followed by the first officer repeating "not in sight missed approach." According to the CVR, a rapid succession of GPWS altitude callouts down to 20 feet followed, as the flight crew attempted to execute the missed approach.

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 The GPWS minimums callout occurred about 12 seconds before impact, when the airplane was descending through about 840 feet msl. The first officer's first statement suggesting the execution of a missed approach occurred about 6 seconds before impact. The captain initiated a missed approach and thrust began increasing about 4 seconds before impact. However, no significant nose-up control column inputs were made until just before initial impact. Analysis of FDR data indicated that, if a missed approach had been initiated 12 seconds before impact (at the GPWS minimums callout), it is likely that the airplane would have successfully cleared terrain by about 450 feet. Analysis of the FDR data also indicated that, if an aggressive missed approach had been initiated 6 seconds before impact (when the first officer made the first missed approach challenge), it is possible that the airplane might have cleared the terrain.

The Safety Board notes that the flight crew would have been gauging the airplane's height above the MDA by referring to the airplane's barometric altimeter (which displays altitude above sea level) and not the radio altimeter (which senses altitude above ground level and upon which the GPWS minimums callout was based) and that the MDA of 560 feet msl was never reached. Nevertheless, the GPWS callouts were a salient cue that should have caused the flight crew to question the airplane's position and the captain to act conservatively and choose to execute a missed approach. The Safety Board concludes that the first officer and flight engineer noted the GPWS callouts and the first officer properly called for a missed approach, but the captain's failure to react properly to the GPWS minimums callout and the direct challenge from the first officer precluded action that might have prevented the accident.

Although the first officer properly called for a missed approach 6 seconds before impact, he failed to challenge the errors made by the captain (as required by Korean Air procedures) earlier in the approach, when the captain would have had more time to respond. Significantly, the first officer did not challenge the captain's premature descents below 2,000 and 1,440 feet. The Safety Board was unable to identify whether the absence of challenges earlier in the approach stemmed from the first officer's and the flight engineer's inadequate preparation during the approach briefing to actively monitor the captain's performance on the localizer approach, their failure to identify the errors made by the captain (including the possibility that they shared the same misconceptions as the captain about the glideslope status/FD mode or the airplane's proximity to the airport), and/or their unwillingness to confront the captain about errors that they did perceive. The Safety Board notes that the captain's failure to brief the localizer approach to back up the expected visual approach could have adversely affected the flight crew's

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 preparation for monitoring the approach. If the captain had briefed the details of the approach, including the various navigational fix definitions and associated altitude constraints, he would have enhanced the flight crew's ability to monitor the approach and challenge any errors he made.

Even if the first officer was attempting to monitor the approach, his ability to identify errors made by the captain would have been impaired by the requirement that he tune his navigation receiver to the UNZ VOR, thus forcing him to look across the cockpit to the captain's instruments to monitor the glideslope/FD status, any indications of glideslope capture on the captain's ADI and HSI, and the airplane's lateral position on the localizer. However, the first officer would have had information on his own HSI and radio magnetic indicator about the airplane's position relative to the VOR (the step-down fix for the descent to 560 feet) and the DME readings that defined the remaining fixes of the approach.

The first officer's ability to monitor the captain was also possibly hindered by the likelihood that he was using a different instrument chart than the captain for the localizer approach. The Safety Board found an out-of-date chart for this approach (dated January 19, 1996) in the cockpit. On the basis of the captain's comments on the CVR, it appears that the captain was using the correct chart (dated August 2, 1996), which included different definitions and names of DME fixes and different crossing altitudes than the out-of-date chart. Thus, if the first officer was using the out-of-date chart, he would have been hindered in monitoring the captain's compliance with the altitude constraints at the fixes.

Although the precise reason(s) for the lack of monitoring by the flight crew could not be determined, the Safety Board concludes that the first officer and flight engineer failed to properly monitor and/or challenge the captain's performance, which was causal to the accident.

Problems associated with subordinate officers challenging a captain are well known. For example, in its study of flight crew-involved major air carrier accidents in the United States, the Safety Board found that more than 80 percent of the accidents studied occurred when the captain was the flying pilot and the first officer was the nonflying pilot (responsible for monitoring). Only 20 percent of the accidents occurred when the first officer was flying and the captain was monitoring. This finding is consistent with testimony at the Safety Board's public hearing, indicating that CFIT accidents are more likely to occur (on a worldwide basis) when the captain is the flying pilot. (See section 2.8 for a discussion of CFIT accidents and prevention strategies, including monitored approaches.) The Board's study found that the failure of first officers to challenge errors (especially tactical decision errors) made by a flying captain was a frequent factor in accidents involving such errors. In addition, the study noted that, while monitoring and challenging a captain's tactical decision error, "a first officer may have difficulty both in deciding that the captain has made a faulty decision, and in choosing the correct time to

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 question the decision." The study concluded that a first officer "may be concerned that a challenge to a decision may be perceived as a direct challenge to the captain's authority."

The Safety Board is concerned that the use of the nonflying pilot in a passive role, while the flying pilot is responsible for the approach procedure, programming the autopilot/FD controls, and monitoring the aircraft flightpath, places an inordinately high work load on the flying pilot and undertasks the nonflying pilot. The Board is also concerned that, when the nonflying pilot has a passive role in the approach, the flying pilot may erroneously consider the lack of input from the nonflying pilot as confirmation that approach procedures are being properly performed. The Board is aware that some international air carriers use the nonflying pilot in a more interactive role during the performance of a nonprecision approach, in which that pilot leads or prompts the flying pilot through the approach procedure by stating the next procedural change, including course, heading, altitude, time, visual contact, or MAP. The Board is also aware that some air carriers employ a "monitored approach" method, with the first officer as the flying pilot and the captain as the monitoring, nonflying pilot until just before landing.

The Safety Board notes that the monitored approach method provides for more effective monitoring by the nonflying pilot because captains are more likely to be comfortable offering corrections or challenges to first officers than the reverse situation. Thus, the Safety Board concludes that monitored approaches decrease the workload of the flying pilot and increase flight crew interaction, especially when experienced captains monitor and prompt first officers during the execution of approaches. However, the Board also notes that, when there are differences in aircraft handling skills between captains and first officers and the approach is not flown using the autopilot, a monitored approach with the captain as the nonflying pilot may not always be appropriate. Therefore, the Safety Board believes that the FAA should conduct or sponsor research to determine the most effective use of the monitored approach method and the maximum degree to which it can be safely used and then require air carriers to modify their procedures accordingly.

Fatigue can be a factor in flight operations. The Safety Board examined several fatigue-related factors, including time of day, recent sleeping patterns, and the number of hours since awakening, to determine whether fatigue was a factor in the accident captain's performance. The Board was unable to obtain information on the recent sleeping patterns of the first officer and flight engineer.

The accident occurred after midnight (about 0042) in the flight crew's home time zone (which is 1 hour behind Guam local time). Research has found that this time of day is often associated with degraded alertness and performance and a higher probability of errors and accidents. The arrival time was also several hours after the captain's normal

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 bedtime (2200 to 2300 Seoul local time) and a time at which his body would have been primed for sleep.

CVR evidence indicated that the captain was tired. At the beginning of the approach, the captain made unsolicited comments related to fatigue, stating "eh...really...sleepy." In its investigation of the 1993 American International Airways accident at Guantanamo Bay, Cuba, the Safety Board noted that individuals often tend to underestimate their own level of fatigue. Thus, the captain's comment could have reflected a significant performance degradation. Neither the first officer nor the flight engineer made similar comments.

According to his family, the captain slept his normal sleep routine in the days before the accident and had an opportunity to receive adequate rest. He also took a nap from 1100 to 1340 (Seoul local time) on August 5 and would therefore have been awake for 11 hours at the time of the accident. The Safety Board has found this time since awakening to be associated with greater errors.

For example, in its investigation of the 1993 accident in Pine Bluff, Arkansas, the Board determined that the captain and first officer had both been awake for 11 hours.

Further, the sleep history provided by the captain's family does not address the quality of sleep he received. For example, the time of the captain's reported nap corresponds to a typical physiological period of wakefulness when napping is difficult204 and of limited efficiency at reducing sleep debt. If the captain actually napped at this time, it suggests that he may have had unusual sleep needs that were not indicated by the number of hours in his reported sleep history.

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 Fatigue degrades all aspects of performance and alertness, and deficiencies associated with fatigue were displayed in many aspects of the captain's behavior. The captain's preoccupation and confusion with the status of the glideslope to the exclusion of other critical information, his incomplete briefing, and his failure to react to the GPWS alerts are typical of fatigue effects that were found to be present in the Guantanamo Bay and Pine Bluff accidents.

On the basis of the time of day, statements recorded on the CVR, and sleep and fatigue research, the Safety Board concludes that the captain was fatigued, which degraded his performance and contributed to his failure to properly execute the approach.

The Safety Board examined Korean Air's Boeing 747 pilot training and proficiency checking program to determine what effect, if any, it may have had on the performance of the flight crew of flight 801. In training its pilots to fly the 747-200 and -300 series airplanes, Korean Air conducted 10 4-hour simulator sessions in which pilots were taught various maneuvers, emergencies, and scenarios, followed by a proficiency check in which pilot performance of certain maneuvers was assessed. The profile for each simulator training session outlined the specific airport, runway, weather, and airplane malfunction to be expected and whether the flight would result in a landing or missed approach. The training curriculum was not varied. Korean Air's Director of Academic Training testified at the Safety Board's public hearing that, at the time of the accident, the company's practice was to follow simulator scenarios exactly as outlined in the training curriculum and that instructors were not permitted to vary the scenarios. The director also indicated that the proficiency checks used the same approaches that had been practiced in the previous simulator training sessions.

Further, the only nonprecision approach practiced throughout the simulator sessions that used DME information was the VOR/DME approach to runway 32 at Seoul's Kimpo Airport. However, the DME at that airport is located on the field, unlike at Guam. No scenario was presented in which pilots were required to count down to and fly past the DME and then count up to the MAP, which was required for the Guam approach. Further, according to the airline's training syllabus, the VOR/DME approach to runway 32 at Kimpo was the only nonprecision approach that Korean Air flight crews were required to perform on their check ride.

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 absence of precise vertical guidance create more demands on pilot skills and cognitive performance than precision approaches. An expert on CFIT accidents testified the following at the Board's public hearing:

 * Nonprecision approaches generally are much more complex than precision approaches. For many pilots, they are less familiar. They are more error-prone. They require [a] more comprehensive briefing. They need particularly careful and accurate monitoring, and it is possible for complex step-down procedures for steps to be missed or to be taken out of step. In other words, to get one step ahead of the airplane could be fatal. Such approaches also need much more carefully managed airplane crew and checklist management, and it is a characteristic of many CFIT accidents that they occur when the crew is preoccupied or distracted by other tasks.

The Safety Board notes that the Air Line Pilots Association (ALPA), in its submission regarding this accident, estimated that air transport pilots typically conduct one to three nonprecision approaches a year and practice these approaches "just as infrequently" in the simulator. In its investigation of the November 12, 1995, accident involving American Airlines flight 1572, an MD-83 that crashed in East Granby, Connecticut, while on final approach to Bradley International Airport in Windsor Locks, Connecticut, the Board found that even relatively minor errors in the monitoring of the execution of a nonprecision approach can lead to an accident.

The Safety Board is concerned that the repeated presentation of a single nonprecision approach scenario throughout simulator training (to the exclusion of all other kinds of nonprecision approaches) provides insufficient training in nonprecision approaches. Specifically, the repetition limits pilots' opportunity to understand and practice the flying techniques necessary to perform the different kinds of nonprecision approaches and limits their ability to successfully apply these techniques to novel situations or unusual approach configurations encountered in line operations, such as the localizer approach at Guam. Further, Korean Air's reliance on the same approach for both training and checking resulted in an inadequate evaluation of a flight crew's ability to execute the varied nonprecision approaches that might be encountered in line operations. Therefore, the Safety Board concludes that Korean Air's training in the

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 execution of nonprecision approaches was ineffective, which contributed to the deficient performance of the flight crew.

In addition, on the basis of the history of similar accidents involving U.S. air carriers, the Safety Board concludes that U.S. air carrier pilots would benefit from additional training and practice in nonprecision approaches during line operations (in daytime visual conditions in which such a practice would not add a risk factor). Therefore, the Safety Board believes that the FAA should issue guidance to air carriers to ensure that pilots periodically perform nonprecision approaches during line operations in daytime visual conditions in which such practice would not add a risk factor.

Safety Board investigators evaluated the performance of the CERAP and Agana tower controllers to determine whether their performance played a role in the circumstances of the accident. FAA Order 7110.65, "Air Traffic Control," prescribes the ATC procedures that controllers are required to follow. The investigation revealed three deviations from those procedures on the part of the CERAP controller.

The CERAP controller failed to provide the flight crew with a position advisory relative to a fix on the final approach course when he cleared flight 801 for the approach. If such a position advisory had been given, as required by paragraph 5-9-4, the pilots might have been prompted to cross-check their radar position with the cockpit DME and other navigational aid indications, thereby improving their situational awareness. In addition, the CERAP controller did not inform the flight crew or the tower controller that he had observed a rain shower (described by the CERAP controller as a "cell" during a postaccident interview with Safety Board investigators) on the final approach path, as required by paragraph 2-6-4. Although the pilots should have been aware of the weather situation because they were using on-board weather radar, their decision-making might have been aided if the CERAP controller had provided his weather observations.

The CERAP controller also failed to monitor the flight after the frequency change to the tower controller. As a result, the CERAP controller did not immediately recognize that the airplane was overdue. (Paragraph 10-3-1 states that a controller who has any reason to believe that an aircraft is overdue should immediately take appropriate action.) If the CERAP controller had been properly monitoring the flight on one or both of the radar displays he had available to him (the en route display and/or the terminal display), he might have observed flight 801 disappear on final approach. Also, the controller might have noticed the approach path warning (low-altitude MSAW alert) that was generated on the en route radar display, which began about 6 seconds before impact

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 and continued until at least 23 seconds afterward. These actions would have resulted in an earlier notification of the accident to emergency rescue personnel and possibly an earlier emergency response. (See section 2.7 for a discussion of the emergency response.)

Further, if the CERAP controller had been monitoring the flight on the terminal radar display, which was located to his immediate right and would have been clearly visible to him, he might have seen the airplane descend prematurely toward high terrain and have been able to alert the flight crew and prevent the accident. This radar display would have shown the flight descending through 2,000 feet msl while almost 7 miles from the airport and outside of the outer marker. The radar display would have also shown the airplane crossing the outer marker almost 800 feet lower than the established crossing altitude of 2,000 feet.

Although the CERAP controller told Safety Board investigators that he did not continue to monitor the flight because he was engaged in other duties about the time of the accident, the ATC transcripts indicated no activity during that time. The transcripts indicated that the controller instructed the flight crew, about 0140:42, to contact the Agana tower. The controller then made a radio transmission to another aircraft about 0140:54. From about 0141:14 to 0141:30, the controller had a conversation with another controller at a different center, and about 0142:05, he acknowledged a transmission from another aircraft. However, the transcripts indicated no further activity until 0143:49, when the CERAP controller called the Agana tower with a flight plan. Thus, the ATC transcripts indicated no activity during the time period beginning 21 seconds before and continuing until 1 minute 23 seconds after the flight 801 crash (which occurred about 0142:26). Therefore, the CERAP controller should have been able to monitor the flight during this time. If the controller had done so, he would have had an opportunity to warn the flight crew of the flight's premature descent and possibly prevent the accident.

The Safety Board concludes that the CERAP controller's performance was substandard in that he failed to provide the flight crew with a position advisory when he cleared the flight for the approach, inform the flight crew or the Agana tower controller that he had observed a rain shower on the final approach path, and monitor the flight after the frequency change to the tower controller. It could not be determined whether the

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text:
1911 Encyclopædia Britannica/Pforzheim

PFORZHEIM, a town of Germany, in the grand duchy of Baden, at the confluence of the Nagold and the Enz, on the northern margin of the Black Forest, 19 m. S.E. of Karlsruhe by rail, and at the junction of lines to Wildbad and Ettlingen. Pop. (1895), 33,345; (1905), 59,395, most of whom are Protestants. Its most interesting buildings are the old palace of the margraves of Baden, and the Schlosskirche, the latter an edifice of the 12th-15th centuries, containing the tombs and monuments of the margraves. Pforzheim is the chief centre in Germany for the manufacture of gold and silver ornaments and jewelry, an industry which gives employment to about 22,000 hands, besides which there are iron and copper works, and manufactures of chemicals, paper, leather, machinery, &c. A brisk trade is maintained in timber, cattle and agricultural produce.

Pforzheim (Porta Hercyniae) is of Roman origin. From about 1300 to 1565 it was the seat of the margraves of Baden. It was taken by the troops of the Catholic League in 1624, and was destroyed by the French in 1689. The story of the 400 citizens of Pforzheim who sacrificed themselves for their prince after the battle of Wimpfen in May 1622 has been relegated by modern historical research to the domain of legend.

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 absence of the CERAP controller's procedural errors, singularly or in any combination, would have prevented the accident or reduced its severity. However, the Safety Board concludes that strict adherence to ATC procedures by the CERAP controller may have prevented the accident or reduced its severity. Therefore, the Safety Board believes that the FAA should develop a mandatory briefing item for all air traffic controllers and ATC managers, describing the circumstances surrounding the performance of the CERAP controller in this accident to reinforce the importance of following ATC procedures.

Since February 1995, the Guam ARTS IIA MSAW system had been intentionally inhibited by the FAA from providing low-altitude alerts inside a 54-nm ring around the ASR-8 radar antenna. The system was inhibited because it had been generating what air traffic controllers believed to be numerous false alerts, or "nuisance warnings." Thus, at the time of the accident, the MSAW system was only available (uninhibited) in a 1-mile-wide band around the ASR-8 radar site, between 54 and 55 nm. Korean Air flight 801 crashed approximately 3 nm southwest of Guam International Airport in an area of rising terrain that would have been covered by the MSAW system if it had not been inhibited.

FAA technical staff and Safety Board investigators conducted a postaccident simulation using the original parameters intended for the system. The simulation results indicated that, if the MSAW system had not been inhibited inside the 54-nm radius, both a visual and aural low-altitude alert would have been generated on the ARTS IIA monitors in the CERAP facility about 0141:22, as the airplane was descending through 1,700 feet msl. Accordingly, the Safety Board concludes that, if the ARTS IIA MSAW system had been operating as initially intended, a visual and aural warning would have activated about 64 seconds before flight 801 impacted terrain, and this warning would have likely alerted the CERAP controller that the airplane was descending below the minimum safe altitude for that portion of the approach.

Flight 801 was under the control of the Agana tower controller at the time that the low-altitude MSAW alert would have been issued by the ARTS II system in the CERAP facility. The Agana tower was not equipped with a functioning terminal radar display. Therefore, for the crew of flight 801 to have received a low-altitude advisory, the CERAP controller (who was still responsible for monitoring the airplane after he initiated a frequency change to the tower controller) would have had to relay the alert to the tower controller, who would then have had to convey the alert to the flight crew. Given the prevalence of CFIT accidents, controllers would be expected to vigilantly monitor the system and provide timely notification to either another controller or a flight crew when

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 an MSAW alert indicates the existence of an unsafe situation. The Safety Board concludes that 64 seconds would have been sufficient time for the CERAP controller to notify the Agana tower controller of the low-altitude alert, the tower controller to convey the alert to the crew of flight 801, and the crew to take appropriate action to avoid the accident.

Because of its periodic evaluations of air traffic facilities, FAA quality assurance staff knew as early as July 1995 that the Guam ARTS IIA MSAW system had been inhibited. The inhibition was cited in a 1995 FAA facility evaluation report but was only classified as an "informational" item. The FAA conducted no followup activities after the 1995 evaluation to determine whether corrective action had been taken to restore the MSAW system to the full service for which it was designed. In April 1997, the FAA conducted a second evaluation of the Guam facility, but the FAA's report on this evaluation did not even note that the ARTS IIA MSAW system was inhibited. Thus, the FAA missed two opportunities not only to recognize that the MSAW system was inhibited to the extent that it was rendered almost completely useless but also to take corrective action. An appropriate corrective action could have prevented this accident. Therefore, the Safety Board concludes that the FAA's quality assurance for the MSAW system was inadequate, and the agency's intentional inhibition of that system contributed to the flight 801 accident.

As previously noted, in this accident there would have been sufficient time (64 seconds), if the MSAW system had generated an alert in the CERAP facility, for the CERAP controller to have relayed the information to the tower controller. However, under different circumstances, an aircraft descending below the minimum safe altitude may not generate an MSAW alert as far in advance, so controllers may have significantly less time to react. In those cases, it would make a critical difference if the MSAW alert were provided directly to the airport tower.

The Safety Board has long been concerned about the issue of aural MSAW alerts in towers. As part of its investigation into the January 1995 Beechcraft A36 accident, the Safety Board found that the FAA did not have a policy regarding the installation of an aural MSAW alert at low-density ATC towers equipped with D-BRITE radar displays. As a result, the Safety Board issued Safety Recommendation A-95-120 on November 30, 1995. Safety Recommendation A-95-120 asked the FAA to develop a policy that would require the installation of aural MSAW equipment in those visual flight rules (VFR) terminal facilities that receive radar information from a host radar control facility and would otherwise receive only a visual MSAW alert.

In June 1996, the FAA stated that it was feasible to install the aural MSAW alert in 112 VFR towers. In July 1997, the FAA stated that 69 of 112 ATC facilities did not have remote displays with aural alarms and that aural alarms at these facilities would be installed by February 1998. In May 1998, the FAA stated that the aural alarms at these 69 remote sites would be operational by the end of that month. However, in March 1998, at the Safety Board's public hearing, the FAA's Deputy Program Director for Air Traffic

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 Operations indicated that the new projected completion date for the installation of aural alarms in VFR towers was April 2000. In October 1998, the Safety Board expressed its concern to the FAA that VFR tower controllers who have visual representation from a distant host radar may not receive an aural alert when aircraft under their control, or with whom they are in radio communication, descend below the minimum safe altitude. The Board asked the FAA to ensure that all VFR tower controllers with visual representation from a host radar would in fact receive such warning. Pending further information from the FAA, Safety Recommendation A-95-120 was classified "Open--Acceptable Response."

On September 29, 1999, a representative from the FAA stated that the agency's management had indicated that the Agana tower was currently receiving aural MSAW alerts. At an October 7, 1999, briefing attended by the FAA Administrator, the Safety Board Chairman, and staff from both agencies, the FAA indicated that 69 MSAW aural alarms had been delivered and that 51 alarms were to be delivered. The FAA expected that the acquisition of these 51 alarms would be completed by October 2000 and that their installation in VFR towers would be completed by April 2001.

On October 12, 1999, the FAA Program Director for Serco Aviation Services told Safety Board staff that the Agana tower has the capability to receive an aural MSAW alert but that, unless the Guam CERAP transfers responsibility for the aircraft's data block, the tower will not receive the warning. The official added that the CERAP does not currently transfer responsibility for the aircraft's data block to the Agana tower; therefore, the tower does not receive an aural MSAW alert.

On October 14, 1999, the FAA Program Director for Air Traffic Operations confirmed that Agana tower was not receiving aural MSAW alerts. In an October 15, 1999, facsimile, the program director indicated that the tower "has the software and hardware capability in place to receive aural alarms." The director further stated that the FAA had issued a policy "to ensure that the facility that is in direct radio communications with the aircraft receives the aural alarm" and that the policy would become effective by November 15, 1999. In a followup telephone conversation with the Safety Board's Director of the Office of Aviation Safety, the program director indicated that a national policy would be issued to ensure that procedures similar to those being implemented at Guam are followed at other VFR towers.

On October 25, 1999, the FAA indicated that the MSAW aural alarms for the ARTS IIA system at Guam were reconfigured on October 24, 1999. The FAA stated that, in the event of a low-altitude alert for an aircraft operating in the vicinity of Guam International Airport, aural alarms will be simultaneously generated at the CERAP and the Agana tower, along with visual low-altitude alerts on the radar displays at both facilities.

On November 2, 1999, the Safety Board received a copy of draft FAA Notice N7210.485, "Minimum Safe Altitude Warning for Remote Tower Displays." According to the notice, facility managers at ATC towers that have aural alarms for MSAW are to ensure that "the operational support facility has adapted the software functionality to ensure the aural alarms operate in the ATCT [air traffic control tower]" and that "aural

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 alarms are received in the ATCT upon transfer of communications." The FAA indicated that the effective date for this notice would be February 1, 2000.

The Safety Board is concerned about the delay in the implementation of Safety Recommendation A-95-120. In addition, the Safety Board is especially concerned that the FAA, until it received queries from the Board, was apparently not aware of, or not addressing, procedural barriers that prevented the installed equipment from being used as intended. However, on the basis of the FAA's apparent continued intention to fully implement this recommendation, it remains classified "Open--Acceptable Response."

Although a fire station was located about 1 mile from the accident site, the first emergency response equipment (dispatched from a different fire station about 3 ½ miles from the accident site) did not arrive on scene until approximately 52 minutes after the accident. Safety Board investigators attempted to determine the reason(s) for the slow emergency response and the extent to which it could have been reduced or avoided.

Because of the air traffic controllers' delayed discovery of the accident, ramp control personnel, who were responsible for emergency notifications, were not aware of the accident until 0158, about 16 minutes after the crash occurred. As discussed in section 2.6.1, if the CERAP controller had been monitoring the flight more closely, this delay might have been eliminated or reduced.

After being notified of the accident by Guam airport ramp control, the Guam Fire Department (GFD) communications center dispatched GFD Engine No. 7, which was stationed about 3 ? miles from the crash site, at 0207. However, Engine No. 7's departure from the station was delayed by 12 minutes because its brake system needed to be recharged with air. Engine No. 7 departed the station at 0219, and its en route response time was 15 minutes. Engine No. 7 was the first emergency response vehicle to arrive at the VOR access road (at 0234, 52 minutes after the accident). The nearest fire station to the accident site was the U.S. Navy Federal Fire Department (located about 1 mile from the accident site). According to Federal dispatch facility logs, that station was not notified of the accident until 0234. The station's Engine No. 5 was then immediately dispatched and arrived at the accident scene at 0239 (a response time of 5 minutes). The Chief of Staff for the Commander, U.S. Naval Forces, Marianas, notified Navy "first responders" to stand by after she learned of the accident at 0216. However, the Navy had not yet received a request for specific Federal firefighting and medical resources; therefore, it would have been inappropriate for the Chief of Staff to have dispatched these resources.

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 The emergency response was further delayed because the VOR access road--a partially paved, single-lane road that was the only ground access to the accident site--was blocked by a section of severed pipe when emergency responders arrived. Emergency responders had to walk to the crash site through steep, muddy terrain and dense vegetation until 0334, when a truck-mounted winch removed the pipe. Fire and rescue personnel stated that only small, isolated fires remained when they were finally able to reach the accident scene with firefighting equipment.

A U.S. Navy emergency medical technician assigned to the Naval Regional Medical Center reached the accident site on foot between 0245 and 0300. He stated that emergency responders established two triage areas to treat survivors. He added that transport of the survivors to hospitals was delayed because of the terrain and limited access to the crash site and the necessity to stabilize patients in triage. The first survivors were transported to hospitals between about 0300 and 0330. Rescue personnel testified at the Safety Board's public hearing that the pace of evacuations increased after the pipe blocking the access road was removed and a landing area for helicopters was set up near the VOR.

The Safety Board is concerned that the first emergency response equipment did not arrive at the accident scene until about 52 minutes after the accident. Although the harsh terrain and the broken pipeline could not have been controlled, the delay caused by air traffic controllers' initial unawareness of the accident, the need to recharge the brake system on the GFD Engine No. 7, and the lack of timely notification to the Federal Fire Department could have been avoided. Thus, the Safety Board concludes that a substantial portion of the delayed emergency response was caused by preventable factors.

The autopsy reports indicated that at least one seriously injured passenger was treated at the accident site. Although the autopsy report for this passenger did not identify a single cause of death (her remains showed evidence of multiple internal injuries but no burns or soot in the airways), the report indicated that she was alive when medical personnel arrived, was treated aggressively, and might have survived if earlier medical intervention and evacuation had occurred. Therefore, the Safety Board concludes that the delayed emergency response hampered the timely evacuation of injured persons, and at least one passenger who survived the initial impact and fire might not have died if emergency medical responders had reached the accident site sooner.

According to public hearing testimony by Guam's Civil Defense Director, at the time of the accident, Guam emergency response authorities had a memorandum of understanding (MOU) with the U.S. Air Force for emergency response but did not have agreements with the U.S. Navy or U.S. Coast Guard. The director further stated that, before the accident, a joint disaster drill had been conducted at the airport, but no drills had been conducted for off-airport crash emergencies. At the public hearing, the Guam Civil Defense Director and other Guam officials stated that a committee, including representatives from Guam, the U.S. Navy, the U.S. Coast Guard, and the U.S. Air Force,

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 had been formed to develop an MOU; an off-airport aircraft accident drill was planned for September 1998; and new radios had been purchased to allow interagency communication and coordination during emergency responses. However, Guam Civil Defense officials told the Safety Board in June 1999 that no MOU had been signed and that a draft of standard operating procedures for joint emergency response was being circulated to agencies for review. Further, Guam Civil Defense officials stated that the planned September 1998 off-airport aircraft accident drill did not take place and that such an exercise was still in the planning stage.

Although it is pleased with the purchase of new emergency radios, the Safety Board concludes that improved formal coordination among Guam's emergency response agencies has not been implemented, and off-airport drills to identify and correct deficiencies in disaster response planning before an accident occurs have still not been conducted in the more than 2 years since the flight 801 accident. Thus, the Safety Board also concludes that actions taken by Guam's emergency response agencies after the accident have been inadequate because they failed to ensure that emergency notifications and responses would be timely and coordinated. Therefore, the Safety Board believes that the Governor of the Territory of Guam should form, within 90 days, a task force comprising representatives from all emergency response agencies on the island, including the appropriate departments within the government of Guam, FAA, Guam International Airport Authority, U.S. Navy, U.S. Air Force, U.S. Coast Guard, Federal Emergency Management Agency, and all other affected agencies, to define and coordinate emergency notification and response procedures to ensure that timely emergency notifications are made to all local and Federal agencies according to need, location, and response time capability. Further, the Safety Board believes that the Governor of the Territory of Guam should require periodic and regularly scheduled interagency disaster response exercises, including an off-airport aircraft accident scenario, in addition to those response drills already required at Guam International Airport in accordance with 14 CFR Section 139.325.

According to Flight Safety Foundation (FSF) accident data, CFIT accidents have killed more passengers and crewmembers than any other type of air carrier accident, and approach and landing accidents accounted for 70 percent of CFIT accidents, with most accident airplanes "in line with the runway" at impact. CFIT accident data also indicated that nonprecision approaches presented a greater risk than precision approaches and that many CFIT accidents involved failed step-down approaches, with flight profiles similar to that of flight 801's approach to Guam. As noted in section 2.5, nonprecision approaches are practiced infrequently by air carrier pilots and generally require more extensive briefings and careful monitoring than a typical instrument approach.

The FSF CFIT task force also identified several common factors found in CFIT accidents, including night conditions, limited visibility, terrain not seen until just before impact, a stabilized descent path approximating a 3° slope, loss of horizontal and/or

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 vertical situational awareness, unfamiliarity with terrain and obstructions, uncertainty about altitudes and/or distance from the airport, navigational equipment improperly set, or information misinterpreted. The Safety Board notes that many of these factors were present in this accident.

On October 16, 1996, the Safety Board issued Safety Recommendation A-96-95, asking the FAA to develop a CFIT program that includes realistic simulator exercises comparable to the successful windshear and rejected takeoff training programs and make training in such programs mandatory for all pilots operating under 14 CFR Part 121. On February 25, 1997, the FAA issued a change to AC 120-51B, "Crew Resource Management," recommending that crew resource management (CRM) training in lineoriented flight training or special purpose operational training modules contain a CFIT scenario. However, the FAA did not require this CFIT training, as urged by the Safety Board. Pending further correspondence from the FAA, Safety Recommendation A-96-95 was classified "Open--Acceptable Response" on November 13, 1997.

A CFIT Education and Training Aid, which was developed under the auspices of the FSF and made available to air carriers in 1997, provides an overall summary of CFIT "traps," outlines causal factors of CFIT accidents, and provides training guidance for specific escape maneuvers. The education and training aid focuses on altimeter errors, procedural errors, misuse of automation, terrain avoidance, and aggressive escape maneuvers. The training materials include a video and a CFIT checklist designed to evaluate mission-specific CFIT risk factors, such as nonprecision approaches, airports near mountainous terrain, duty time, and weather factors. Thus, because CFIT is one of the leading categories of air carrier accidents and this type of accident is likely to increase as worldwide air traffic levels increase, the Safety Board concludes that CFIT accident awareness and avoidance training is an important accident reduction strategy and should be mandatory for all pilots operating under 14 CFR Part 121.

The Safety Board is disappointed that the FAA has not yet mandated CFIT training, despite its demonstrated value to air carrier flight crews and in the reduction of CFIT accidents. On August 11, 1999, the FAA stated that it had initiated a notice of proposed rulemaking (NPRM) to mandate CFIT training. The FAA indicated that the NPRM would be published in December 2000. Because of the FAA's planned rulemaking, Safety Recommendation A-96-95 remains classified "Open--Acceptable Response." However, the Safety Board notes with concern that the FAA's expected publishing date for the NPRM (December 2000) would occur more than 4 years after the issuance of the recommendation. Experience has shown that implementation of a final rule could take several additional years. In light of the fact that the CFIT training program is already available to the industry, this delay appears unnecessary and unreasonable. Therefore, the Safety Board urges the FAA to expedite this rulemaking.

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Some airlines have adopted a "constant angle of descent" technique for nonprecision approaches. This technique involves descending on a constant descent angle toward the runway and meeting all of the crossing restrictions of the nonprecision approach procedure while avoiding intermediate level-offs. For this technique, the crossing altitudes depicted on the approach chart are used only as the bottom portion of a window through which the airplane passes as it descends. In most cases, the descent angle is about 3°, except in instances in which terrain or obstructions require a steeper descent. Because of terrain factors, some currently approved nonprecision approaches are not amenable to being flown with a constant angle of descent method.

One method for flying a constant angle of descent, in the absence of a groundbased glideslope signal, involves the use of on-board flight management system (FMS) or GPS equipment that provides electronic guidance for a constant angle of descent. This method uses the same flight instrument and FD displays as with an ILS approach. The FMS or GPS equipment, one or both of which is widely installed in newer airplanes, provides precise, real-time information about airplane position.

Under FAA Order 8260.47, "Barometric Vertical Navigation Instrument Procedures Development," issued May 26, 1998, some airlines have received approval to use preprogrammed FMS/GPS approaches that include three-dimensional navigation guidance to the MAP, which is expressed as a barometric decision altitude. The advantages of this method include greater precision, lower pilot workload, and the ability to obtain FD guidance and couple the autopilot to fly the approach automatically. Pilots are not required to use step-down fixes, which removes the chance for misinterpreting the distance to the runway or the proper altitude for that distance and provides for a stabilized approach throughout the descent. The Safety Board concludes that, by providing vertical guidance along a constant descent gradient to the runway, the use of on-board FMSand/or GPS-based equipment can provide most of the safety advantages of a precision approach during a nonprecision approach. Therefore, the Safety Board believes that the FAA should require that all air carrier airplanes that have been equipped with on-board navigational systems capable of providing vertical flightpath guidance make use of these systems for flying nonprecision approaches whenever terrain factors allow a constant angle of descent with a safe gradient.

The Safety Board notes that it is likely that most air carrier airplanes will be equipped with on-board FMS and/or GPS equipment over the next several years and that the lack of such equipment may ultimately result in the loss of approach capability to certain runways for those airplanes not so equipped. Further, the Board acknowledges that terrain along the approach courses to some runways may preclude a constant angle of descent with a safe gradient, thus resulting in the loss of approach capability to certain runways. However, on the basis of the safety advantages of the constant angle of descent with vertical guidance versus step-down approaches, as demonstrated in the circumstances of this accident, the Safety Board believes that the FAA should require, within 10 years,

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 that all nonprecision approaches approved for air carrier use incorporate a constant angle of descent with vertical guidance from on-board navigation systems.

For those airplanes not yet equipped with on-board navigational systems capable of providing vertical flightpath guidance, an alternative method allows pilots to approximate a constant angle of descent. This method requires using a published approach procedure that incorporates a defined point along the final approach course to begin a constant angle descent to the runway of about 3?; this descent point and descent angle also fulfill the minimum crossing altitudes at each step-down fix of the nonprecision approach. If pilots are provided a tabular means of cross-referencing the distance from the runway (measured by DME) and the proper altitude for that distance, they can adjust the airplane's rate of descent to approximate a constant angle. The advantages of this method include greater awareness of the airplane's position on the approach path and a more stabilized approach, but there is additional workload involved in the cross-referencing of altitude and distance.

In Safety Recommendation A-96-128, issued on November 13, 1996, the Safety Board asked the FAA for the incorporation of constant angle descents instead of stepdown criteria. The FAA indicated that it has made progress in providing some of the information pilots need to approximate a constant angle of descent (descent angles and gradients to the runway from a defined starting point). However, the FAA continues to provide insufficient information on approach charts to cross-reference DME distances and altitudes.

Thus, the Safety Board concludes that the safety of executing a nonprecision approach using the constant angle of descent, or stabilized descent technique, would be enhanced by adding to approach charts the cross-referenced altitudes versus distance from the airport. Therefore, the Safety Board believes that the FAA should include, in nonprecision approach procedures, tabular information that allows pilots to fly a constant angle of descent by cross-referencing the distance from the airport and the barometric altitude.

At the time of the flight 801 accident, no Korean Air airplanes were equipped with enhanced GPWS nor were they required to be so equipped. Further, enhanced GPWS was not available for the 747-300 at the time of the accident.

The Safety Board notes that postaccident enhanced GPWS simulations conducted by AlliedSignal indicated that, if flight 801 had been equipped with enhanced GPWS, an aural "CAUTION TERRAIN" warning and a yellow visual terrain depiction on the color weather radar display would have been issued about 60 seconds before impact. An aural "TERRAIN TERRAIN" and "PULL UP" warning and a red visual terrain depiction on the weather radar scope would have been issued about 45 seconds before impact and would have sounded continuously until completion of a successful escape maneuver or impact.

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 Safety Recommendation A-96-101, issued on October 16, 1996, asked the FAA to examine the effectiveness of enhanced GPWS equipment and, if found effective, require all transport-category aircraft to be equipped with an enhanced GPWS that provides pilots with an early warning of terrain. In a May 4, 1999, letter to the Safety Board, the FAA stated that it issued an NPRM in August 1998 to require terrain awareness and warning system (TAWS) equipment (the name used in the NPRM for enhanced GPWS) on all civil turbine-powered aircraft with six or more passenger seats within 4 years of the issuance of a final rule. Pending the Board's evaluation of the FAA's completed action, Safety Recommendation A-96-101 was classified "Open--Acceptable Response" on July 13, 1999.

However, on May 12, 1999, the Safety Board expressed concern that the 4-year installation time frame was too long for retrofitting enhanced GPWS to existing turbinepowered airplanes that currently lack any GPWS protection. As a result, the Board issued Safety Recommendation A-99-36, urging the FAA to shorten the proposed installation period for these airplanes to 3 years (with a completion deadline of May 2002).

In a July 26, 1999, response to the Safety Board, the FAA indicated that it was "committed to installing and using TAWS as expeditiously as possible." The FAA stated that the final rule would require installation of TAWS within 1 year after the effective date on new-production airplanes and within 4 years for existing airplanes. The FAA added that the installation timetable was based on "product availability" and the "manufacturing approval process."

The Safety Board notes that, on August 16, 1999, the FAA issued a technical standard order for TAWS equipment (specifications and installation requirements) and that the proposed final rule for TAWS installation was scheduled to be issued by March 2000. The Board acknowledges the FAA's progress to date on TAWS issues but notes with disappointment that the 2005 installation deadline is 3 years longer than urged in Safety Recommendation A-99-36 for existing airplanes that are not currently required to have a GPWS. The Board continues to urge that the installation of enhanced GPWS be expedited not only for those airplanes covered by Safety Recommendation A-99-36 but also for the transport-category airplanes covered by Safety Recommendation A-96-101. Pending further action by the FAA, the Safety Board classifies Safety Recommendations A-96-101 and A-99-36 "Open--Acceptable Response."

Approach chart vendors use various methods of depicting obstructions and high terrain on approach charts. On the plan view, some vendors use contour lines and color

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 shading for various height gradients and symbols for high obstructions, and others use broader colored areas with the minimum sector altitude for obstacle clearance printed over each area. However, no chart vendor depicts terrain or obstructions on the profile view, which depicts the inbound approach course descent profile from an initial approach fix to a landing or missed approach. Other than the depiction of certain obstruction heights, there is no FAA requirement or standardized format to depict terrain on approach charts. The Safety Board notes that Nimitz Hill was not depicted on the Guam runway 6L ILS approach chart.

During an instrument approach, pilots generally refer to the plan view until they are established on the inbound approach course, usually on the intermediate and final approach segments. Once on the inbound approach course, pilots generally shift their attention on the approach chart from the plan to the profile view. Thus, the Safety Board concludes that terrain depiction on the profile view of approach charts could result in increased flight crew awareness of significant terrain on the approach path. The Board recognizes that logistical problems may be associated with obtaining and including this information and that not all users agree that obstacle depiction on the profile view is necessary and helpful. (See section 1.18.4.2.) Nevertheless, the Safety Board believes that the FAA should evaluate the benefits of depicting terrain and other obstacles along a specific approach path on the profile view of approach charts and require such depiction if the evaluation demonstrates the benefits.

Charting companies that publish instrument procedures receive the pertinent information from the FAA on its Form 8260. This form includes data for the terminal area as well as final approach and missed approach standards for a specific instrument procedure. The manager of the FAA's Western Flight Procedures Development Branch testified at the Safety Board's public hearing that, when an approach procedure is completed but before it is published, the procedure is distributed to industry user groups, including ALPA, the Air Transport Association, the Aircraft Owners and Pilots Association, and airport operators, for review. The manager stated that the purpose of this user review is to ensure that the final product is safe, accurate, and intelligible. The Safety Board agrees with and endorses this practice. However, the Board notes that the FAA does not provide user groups with the approach procedure in its final, graphical form as it will be published and used. Rather, user groups are only given FAA Form 8260, which describes the approach in words and numbers.

Industry user groups, including ALPA (according to its submission to the Safety Board regarding this accident), have stated that the format of FAA Form 8260 makes it difficult for them to evaluate the procedure. Thus, the Safety Board concludes that valuable user group reviews of proposed new instrument procedures are hampered by the format in which the information is disseminated; thus, user groups may not be able to effectively evaluate whether a procedure is safe, accurate, and intelligible. Therefore, the

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 Safety Board believes that the FAA should provide user groups, along with Form 8260, draft plan and profile views of instrument procedures to assist the groups in effectively evaluating proposed new procedures.

As discussed in sections 1.17.2.3 and 1.17.5.1, Korean Air established a CRM program and undertook several other safety initiatives in response to previous accidents. The company also had supervisor briefing and airport familiarization programs, both of which exceeded Korean regulatory requirements. (For more information about these programs, see section 1.17.3.)

The Safety Board recognizes that these efforts indicated a positive approach to safety. However, the supervisor briefing, which could have assisted the flight crew in preparing for the approach, did not review important items, such as NOTAMs or the currency of approach charts. Also, the airport familiarization video did not adequately prepare the crew for the possibility of a nonprecision approach in IMC, nor did it note that the DME was not colocated with the localizer. Further, as discussed previously, some of Korean Air's training and operational procedures, such as the limited number and variety of approach scenarios, lack of an interactive role for the nonflying pilot, and lack of documented cockpit approach procedures that clearly defined crewmember duties, contributed to the flight crew's deficiencies in this accident.

Korean Air experienced a series of accidents (beginning before and continuing after the Guam accident) involving crew coordination and performance (see section 1.17.5). These accidents raise broader questions about the adequacy of the company's training and operational procedures. The airline did take action in response to some of these accidents to address the safety problems brought to light. However, the continued occurrence of crew error accidents called for a broad in-depth assessment of the airline's flight operations to determine how best to mitigate opportunities for such errors.

At the Safety Board's public hearing, the Korean Air Deputy Director of Flight Operations appeared to recognize that, before the accident at Guam, Korean Air had not been placing sufficient emphasis on flight safety and particularly on pilot training. He testified:
 * Looking back upon this accident we feel that most of our management up to now has been [ ] perhaps too short-term, short-[sighted], and superficial in its nature. ...from this point on for the purpose of ascertaining safe flight operations we plan to make long-term plans and spare no resources in [attaining] this final objective of flight safety. Accordingly, we will adjust our management systems and invest all the more heavily into training and program development.

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 The Safety Board acknowledges that, since the Guam accident, Korean Air has taken significant management, operational, and flight crew training actions. However, in light of the specific deficiencies that were discovered during the investigation of this accident and Korean Air's accident and incident history, the Safety Board concludes that, at the time of the flight 801 accident, there were underlying systemic problems within Korean Air's operations and pilot training programs that indicated the need for a broad safety assessment of these programs.

The KCAB is charged with oversight of the Korean civil airlines. At the time of the accident, two KCAB operations inspectors were assigned to provide oversight of Korean Air's flight operations. Korean Air pilots who were designated by the KCAB as check airmen and examiners conducted flight instruction, check rides, and proficiency checks and issued type ratings. The KCAB inspectors provided an annual evaluation of the flight skills of the check airmen and examiners but did not observe proficiency checks or check rides on Korean Air's wide-body fleet.

According to its director, the KCAB routinely conducts one annual safety inspection, four quarterly inspections, and an average of 40 random inspections of the airline each year. The director added that the two safety inspectors assigned to Korean Air at the time of the accident also had oversight duties at another Korean carrier. Regardless of the number of inspections of Korean Air performed by the KCAB, its failure to identify and monitor trends within the airline that might be indicative of safety problems raises questions about the adequacy of KCAB's oversight of Korean Air. Further, KCAB officials acknowledged that the agency, because of personnel workload constraints, frequently relied on Korean Air to self-report corrective actions taken in response to KCAB inspections and did not confirm directly that identified problems had been addressed by the airline.

As previously noted, the syllabus for Korean Air's KCAB-approved simulator training program described the scenarios used in training, type ratings, and proficiency checks, and these scenarios were followed repetitively, without deviation, during training

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 exercises. Further, the training and checking scenarios incorporated an inadequate number and variety of nonprecision approach procedures. As a result of the airline's rigid adherence to a curriculum that provided an inadequate variety of approaches, flight crews were inadequately prepared to conduct nonprecision approaches. Also, cockpit approach procedures (for example, for the flying and nonflying pilot roles) were taught anecdotally and were not documented. After the accident and discussions with Safety Board investigators, the KCAB asked Korean Air to modify its simulator training syllabus to include a diversity of approach scenarios and improve its CRM program. Korean Air stated that it complied with these requests. Implementing and maintaining the highest levels of aviation safety requires an ongoing relationship between the regulator (in this case, the KCAB) and the airline (in this case, Korean Air). Each entity plays an essential role: one complies with standards of safety, and the other ensures that such compliance is maintained. One researcher described the role of the regulator as follows:

 * Regulators are uniquely placed to function as one of the most effective defen[s]es against organizational accidents. They are located close to the boundaries of the regulated system, but they are not of it. This grants them the perspective to identify unsatisfactory practices and poor equipment that the organization has grown accustomed to or works around.

The Safety Board acknowledges that, in October 1998, after several accidents and incidents following the crash of flight 801, the Korean Ministry of Construction and Transportation (of which the KCAB is a part) ordered a 6-month suspension of 138 flights on 10 of Korean Air's domestic routes and ordered it to reduce service on the Seoul-toTokyo route. The Safety Board further acknowledges that KCAB operations inspectors now assigned to Korean Air have type ratings in the airplanes that the airline operates. However, as discussed previously, at the time of the flight 801 accident, there were signs suggesting underlying systemic problems within Korean Air's operations and pilot training programs that indicated the need for a broad safety assessment of these programs. No such assessment was carried out by Korean Air or the KCAB before the accident. Thus, the Safety Board concludes that the KCAB was ineffective in its oversight of Korean Air's operations and pilot training programs.

The FAA issues operations specifications to foreign air carriers operating into the United States pursuant to 14 CFR Part 129. The FAA also assigns a POI to each foreign air carrier to provide oversight to that carrier. The POI for Korean Air at the time of the

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 accident stated that oversight of foreign carriers under Part 129 included inspections of trip records and facilities in the United States and ramp inspections of airplanes and crews when they were in the United States or its territories. However, the POI stated that the FAA did not inspect, approve, or oversee a foreign airline's training program or any of its manuals or accomplish line checks or en route inspections on board foreign airlines. (There is no requirement that a foreign carrier provide the FAA POI with flight operations or training manuals.) The POI also stated that there was no formal interaction between the KCAB and the FAA regarding their respective oversight activities relating to Korean Air.

The Safety Board notes that the purpose of the FAA's International Aviation Safety Assessment (IASA) program is to ensure that foreign air carriers operating in the United States are receiving adequate oversight by their respective civil aviation authority (CAA). The FAA developed this program in response to an identified need to oversee foreign carriers operating to the United States; however, the FAA's assessment under that program is limited to an evaluation of the foreign CAA's ability to provide oversight in accordance with ICAO Annex 6 standards. The FAA does not directly assess whether foreign carriers are receiving such oversight or are complying with Annex 6. When the FAA assessed the KCAB in 1996, the FAA concluded that the KCAB was capable of overseeing Korean air carriers in accordance with ICAO safety standards, and Korea was therefore given a Category I rating (the highest rating of the three IASA categories). The FAA indicated that it would reassess a country that has air carriers operating into the United States if there was any reason to question whether that country was meeting its international safety oversight obligations.

The substantial number of Korean Air crew-related accidents and incidents, the deficiencies in Korean Air's pilot training program, and the lack of documented cockpit procedures suggest that Korean Air had not fully complied with the intent of paragraph 9.3.1 of ICAO Annex 6, which states that operators "shall establish and maintain a ground and flight training program...which ensures that all flight crew members are adequately trained to perform their assigned duties. [The training program] shall also include training in knowledge and skills related to human performance and limitations...[and] shall ensure that all flight crew members know the functions for which they are responsible and the relation of those functions to the functions of other crew members."

The reliability of the FAA's assessment and rating of a country's CAA under the IASA program is becoming ever more important in light of increases in code-sharing and other alliances involving U.S. and foreign carriers. U.S. carriers are likely to view a positive assessment by the FAA and the resulting Category I rating as an indication that the country's airlines are receiving adequate oversight and are therefore maintaining an adequate level of safety. However, even though Korea had received and maintained a Category I rating, the evidence developed in this investigation (including that only two operations inspectors were assigned to Korean Air and that neither was type rated for the 747, as well as the deficiencies in the KCAB's oversight of Korean Air) and Korean Air's accident and incident record (both before and after the flight 801 crash) suggest that the FAA's IASA program was not adequate in its scope and depth to determine the capacity of the KCAB to fully assess Korean Air's level of safety or ensure that Korean Air was

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 receiving adequate oversight. The Department of Transportation Office of Inspector General's (DOT/IG) audit report, titled Aviation Safety Under International Code Share Agreements, reached a similar conclusion. The DOT/IG report noted that the FAA's assessment under the IASA program "is quite different from a judgment about the safety practices of an individual carrier." The report further noted that the "FAA is itself a civil aviation authority that meets international standards, but that is materially different from a conclusion that all U.S. carriers therefore follow sound safety practices."

The Safety Board concludes that the FAA's IASA program (which evaluates a foreign CAA's ability to provide adequate oversight for its air carriers) is not adequate to determine whether foreign air carriers operating into the United States are maintaining an adequate level of safety. The Board notes that the DOT/IG's audit report recommended that U.S. carriers perform safety assessments of foreign carriers as a condition of approval to enter into code share agreements and that the FAA should consider the results of those assessments when performing IASA reviews. Further, the Safety Board believes that the FAA should consider the accident and incident history of foreign air carriers as a factor when evaluating the adequacy of a foreign CAA's oversight and whether a reassessment may be warranted.

2.9.3.1 Independent Accident Investigation Authority

The entity responsible for investigating aviation accidents and incidents in Korea is an office within the KCAB known as the Aviation Safety Division. Thus, Korea has no independent accident investigation authority. Experience has shown that an accident investigation authority that is not independent of the regulatory authority may not be as objective as necessary to identify and recommend changes. A proper accident investigation requires a review of the practices and procedures of the responsible regulatory agency and their possible role in the accident. Because the results of such an assessment may necessitate conclusions and recommendations that are critical of, or adverse to, the regulatory agency or its officials, many countries have concluded that no accident investigation entity could fully perform such a function unless it was separate and independent from the regulatory agency.

Annex 13 to the Convention on International Civil Aviation (paragraph 5.4) states that "the accident investigation authority shall have independence in the conduct of the investigation and have unrestricted authority over its conduct." On November 21, 1994, the Council of the European Union (EU) adopted a directive that specifies that EU Member States shall ensure, by November 21, 1996, that aviation accident and serious incident investigations are conducted or supervised by a permanent body or entity that is functionally independent of the national aviation authorities responsible for regulation and oversight of the aviation system. All EU members have complied with, or are in the process of complying with, the intent of this directive. The Safety Board concludes that an independent accident investigation authority, charged with making objective conclusions and recommendations, is a benefit to transportation safety.

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The Safety Board was unable to validate data from 11 retrofitted sensors on the accident airplane's FDR because Korean Air lacked complete and accurate documentation information for them. Although the data from the retrofitted sensors were not critical in the investigation of this accident, the data might have been important under other accident circumstances. For FDR data to be useful during an accident investigation, accurate documentation that is readily available to investigators after an accident is needed.

After taking delivery of an airplane from a manufacturer, many airlines provide additional data to be recorded on the FDR by retrofitting the airplane with additional sensors or recording additional data from a flight data acquisition unit. Such retrofits are often mandated by the governing CAA. In addition to the flight 801 accident, the Safety Board has investigated several other recent accidents in which airlines were unable to provide accurate and complete information from a retrofitted FDR because the airlines were unable to provide FDR documentation necessary for a complete and thorough readout. Thus, the Safety Board often lacked critical data for a reconstruction of the airplane's motion and the flight crew's performance, which prolonged some investigations.

The Safety Board has long been concerned about inadequate FDR documentation. Since the early 1970s, the Board has made recommendations to improve FDR data verification and documentation. In 1991, concerns about the airworthiness of FDRs resulted in two safety recommendations to the FAA (A-91-23 and -24) aimed at developing a permanent policy for FDR maintenance and record-keeping. Safety Recommendation A-97-30 asked the FAA to publish, by January 1998, a promised AC addressing the installation and maintenance of FDRs.

On October 5, 1999, the FAA issued AC 20-141, "Airworthiness and Operational Approval of Digital Flight Data Recorder Systems." The purpose of the AC is to provide "guidance on design, installation, and continued airworthiness of Digital Flight Data Recorder Systems." Appendix 1 to the AC, "Standard Data Format for Digital Flight Data Recorder Data Stream Format and Correlation Documentation," provides "a standard for the data stream format and correlation documentation that operators must maintain to aid accident investigators in interpreting recorded flight data." The appendix details how to develop a document for each airplane that would provide the detailed information needed by Safety Board investigators to transcribe each parameter recorded by an FDR.

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 The Safety Board is concerned that AC 20-141 was not finalized until more than 8 years after the issuance of Safety Recommendations A-91-23 and -24. Nonetheless, the Board is pleased that the AC is now final and that it will provide airlines with critical and necessary guidance to properly document FDR parameters and systems. As a result, information from FDRs will be provided in the format needed by the Board for a complete and accurate readout.

In addition to AC 20-141, ICAO Annex 6, Part I, "International Commercial Air Transport--Aeroplanes," includes Attachment D, Flight Recorders. Section 3 of the attachment, entitled "Inspections of flight data and cockpit voice recorder systems," provides guidance to Member States on the continued airworthiness of FDR systems, such as details on how to conduct annual checks of every FDR parameter, including recorded signal and transcribed engineering units. Paragraph 3.2.c states that "a complete flight from the FDR should be examined in engineering units to evaluate the validity of all recorded parameters." In addition, paragraph 3.2.d states "the readout facility should have the necessary software to accurately convert the recorded values to engineering units and to determine the status of discrete signals." If Korean Air had been following this ICAO guidance and performing annual checks on all of the FDR parameters for the accident airplane, the airline would have been able to determine the conversion equations necessary to complete an FDR readout or would have been able to discover and correct the FDR parameter documentation discrepancies.

As the number of international flights increases, the possibility of accidents involving foreign aircraft within the United States also increases. The Safety Board concludes that it is critical that thorough documentation of the information recorded by an FDR be available for foreign- or U.S.-registered air transport airplanes that fly into or out of the United States. In accordance with the interagency group on international aviation protocol, the Board will introduce AC 20-141 at the next ICAO flight recorder panel meeting, with a proposal that the AC be adopted as the international standard and recommended practice for FDR systems.

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