1974 — Dec 1, TWA Flight 514 Flies into Mt. Weather, VA — 92

— 92 Faith, Nicholas. Black Box: Why Air Safety is no Accident. London: Boxtree, 1996.
— 92 NTSB AAR Trans World Airlines…727-231, N54328, Berryville, VA, Dec 1, 1974 1975,
— 92 Suburban Emergency Management Project. “Horrific TWA Crash…” Nov 20, 2008.

Narrative Information

NTSB: “At 1110 e.s.t., December 1, 1974, Trans World Airlines, Inc., Flight 514, a Boeing 727-231, N54328, crashed 25 nautical miles northwest of Dulles International Airport, Washington, D. C. The accident occurred while the flight was descending for a VOR/DME approach to runway 12 at Dulles during instrument meteorological conditions. The 92 occupants — 85 passengers and 7 crewmembers — were killed and the aircraft was destroyed.

“The National Transportation Safety Board determines that the probable cause of the accident was the crew’s decision to descend to 1,800 feet before the aircraft had reached the approach segment where that minimum altitude applied. The crew’s decision to descend was a result of inadequacies and lack of clarity in the air traffic control procedures which led to a misunderstanding on the part of the pilots and of the controllers regarding each other’s responsibilities during operations in terminal areas under instrument meteorological conditions. Nevertheless, the examination of the plan view of the approach chart should have disclosed to the captain that a minimum altitude of 1,800 feet was not a safe altitude.

Contributing factors were:

(1) The failure of the FAA to take timely action to resolve the confusion and misinterpretation of
air traffic terminology although the Agency had been aware of the problem for several years.

(2) The issuance of the approach clearance when the flight was 44 miles from the airport on an unpublished route without clearly defined minimum altitudes; and

(3) Inadequate depiction of altitude restrictions on the profile view of the approach chart for the VOR/DME approach to runway 12 at Dulles International Airport.” (NTSB 1975, 1-2)

“Trans World Airlines, Inc., Flight 514 was a regularly scheduled flight from Indianapolis, Indiana, to Washington, D. C., with an inter mediate stop at Columbus, Ohio. There were 85 passengers and 7 crewmembers aboard the aircraft when it departed Columbus….

“At 1036, the Cleveland Air Route Traffic Control Center (ARTCC) informed the crew of Flight 514 that no landings were being made at Washington National Airport because of high crosswinds, and that flights destined for that Airport were either being held or being diverted to Dulles International Airport.” (NTSB 1975, 2-3) ….

“…it is clear that this was an operational accident and that the crew knowingly descended to approximately 1,800 feet after being cleared for the approach. The basic questions requiring resolution are (1) why did the crew knowingly descend to 1,800 feet in an area where the terrain obstacles extended almost up to that altitude; and (2) why did the approach clearance not include
an altitude restriction under the circumstances of this case….” (NTSB 1975, 27)

“Controllers are trained in the air traffic control procedures and the terminology associated with IFR navigation. Pilots, on the other hand, are trained in the operation of the aircraft, air traffic control procedures, and terminology essential to safe operation of aircraft in the airspace system. However, as this case demonstrates, imprecise terminology, unresolved differences of opinion, and unnoticed changes in the definitions and procedures can result in an inadequate understanding on the part of one or both of the participants in the air traffic control situation….

“At the Safety Board’s public hearing, FAA witnesses testified that they were not aware that there was any potential misunderstanding on the part of pilots as to the meaning of the term “cleared for the approach, ” in a case where a nonprecision approach is made, particularly when the clearance was issued a long distance from the airport. The evidence, however, does not support this conclusion, since, for several years prior to this accident, various organizations had perceived a problem in the use of the term “cleared for the approach.”

“Ironically, approximately 6 weeks before the TWA accident an air carrier flight, after being “cleared for the approach,” descended to 1,800 feet while outside of the Round Hill intersection during a VOR/DME approach to runway 12 at Dulles. The carrier involved had implemented an anonymous safety awareness program, was in fact made aware of the occurrence, and subsequently issued a notice to its flightcrews to preclude the recurrence of a near-fatal misinterpretation of an approach clearance. The Board is encouraged that such safety awareness programs have been initiated. It is through such conscientious safety management that the expected high level of safety in air carrier operations can be obtained. In retrospect, the Board finds it most unfortunate that an incident of this nature was not, at the time of its occurrence, subject to uninhibited reporting and subsequent investigation which might have resulted in broad and timely dissemination of the safety message issued by the carrier to its own flightcrews”

“Both the USAF and TWA had pointed out to the FAA that the terminology “cleared for the approach” could be misinterpreted and that pilots might understand that they could descend unrestricted unless a specific altitude restriction was included in the clearance. With respect to the crew of TWA 514, the conversation in the cockpit as reflected in the CVR transcript permits no other conclusions than that they assumed the clearance received permitted an unrestricted descent to 1,800 feet. Sub-questions requiring discussion are whether other available information should have indicated to the crew the unsafe nature of such a descent and why the crew was not alerted at least to the point of making inquiry to ATC.

“Considering the number of times the captain examined this chart after being informed that he was to divert to Dulles he should have realized that the minimum altitude of 1,800 feet might not be a safe altitude. Although the captain did not know his exact position relative to the terrain when he received the approach clearance, the Board believes that with his VOR tuned to Armel and with the information provided by that navigational aid, he should have been able to read his DME range from Armel. At the time he received the clearance, he was about 44 nmi from Arme1 on the 300° radial inbound to the station. By reference to the approach chart, he should also have been able to identify the high obstacles between that position and the Round Hill intersection. With that information, he should have been able to determine that 1,800 feet was not an adequate altitude to provide terrain clearance of 2,000 feet in this designated mountainous area. If he did not realize that he was over a designated mountainous area, he should have applied terrain clearance of 1,000 feet as prescribed for nonmountainous areas. He did notice the 3,400 feet associated with the course between Front Royal and Round Hill. That should have suggested that he should reexamine his decision regarding the descent to 1,800 feet. If he had questioned the controller regarding the minimum altitude in the area of his aircraft, he should have received information that would have alerted him that he could not descend to 1,800 feet until after he passed Round Hill.

“The information available to the pilot, including the approach chart, should have alerted the crew that an unrestricted descent would be unsafe. It does appear to the Board that there was a deficiency in the chart. This particular approach chart depicted the profile view from the final approach fix to the airport. It did not depict the intermediate fix, Round Hill, with its associated minimum altitudes. This information was available from the plan view of the chart, but it appears
that the crew gave their primary attention to the profile. If this was the case, it may have led the crew to discount the other information available on the chart and to continue their descent on the assumption that it was permissible by reason of the clearance they received.

“The second major question deserving consideration is the role of the ATC system in this accident, specifically why TWA 514 was not given an altitude restriction in its approach clearance. The testimony of all FAA witnesses, including the controller, was consistent in stating that Flight 514 was not a “radar arrival;” that because of this fact the controller was not required to implement the provisions of paragraph 1360 of the FAA Handbook 7110.8C; and that they considered TWA 514, after intercepting the 300° radial of Armel, as proceeding on its own navigation and as being responsible for its own obstacle clearance….

“The counterposition is that Flight 514 was operating in a radar environment, was receiving at least one type of radar service, and was on a course which would lead directly to the Round Hill intermediate approach fix. Furthermore it had been advised that the reason for the vector to the 300° radial was for a VOR/DME approach for runway 12. Consequently, it should have received services, including altitude restrictions. as set forth in Paragraph 1360 of 7110.8C.

“In evaluating these facts, the one issue present is whether the handling of Flight 514 required the provision of an altitude restriction. FAA witnesses agreed that, had Flight 514 been classified as a radar arrival within the meaning of the handbook, the flight would have been given an altitude restriction until it reached Round Hill. In resolving this issue, the Board has been troubled by the fact that ATC procedures are almost always dependent upon the usage of certain specified phrases and terms, many of which have no established definitions and mean different things to controllers and pilots.

“The term “radar control” is an example. The pilot witnesses believed that, when they were operating in a traffic control radar environment, they were being controlled by radar. The controller group was aware that this was not always the case, but the FAA apparently did not perceive the difference of understanding, and the efforts made by the FAA to clarify when an aircraft was or was not radar controlled did not eliminate the confusion.

“The Board concludes that based on the criteria in 7110.8C the system allowed for the classification and handling of Flight 514 as a nonradar arrival. The Board, however, believes that the flight should have been classified and handled as a “radar arrival.”….

“The system should clearly require controllers to give the pilots specific information regarding their positions relative to the approach fix and a minimum altitude to which the flight could descend before arriving at that fix. Pilots should not be faced with the necessity of choosing from among several courses of action to comply with a clearance.

“The Board believes that the clearance, under these circumstances, should have included an altitude restriction until the aircraft had reached a segment of the published approach procedure or the issuance of the approach clearance should have been deferred until the flight reached such segment. Therefore, the Safety Board concludes that the clearance was inadequate and its issuance and acceptance was the result of a misunderstanding between the pilot and the controller….” (NTSB 1975, 29-32)

Therefore, the Safety Board concludes that it is essential that a lexicon of air traffic control words and phrases be developed and made available to all controllers and pilots who operate within the National Airspace System. Additionally, there should be one book of procedures for use by both pilots and controllers so that each will understand what to expect of the other in all air traffic control situations. This manual must be used in the training of all pilots and controllers.” (NTSB 1975, 33)

“The issue of when flights are or are not radar arrivals must also be resolved. It is difficult for a pilot who is operating in a radar environment and communicating with a radar controller to realize that, under some circumstances, his flight is, without formal notification, considered to be a nonradar arrival and subject to a different ATC procedure. Specifically, he may not realize that the responsibility for obstacle clearance shifts from the controller to the pilot under some circumstances without the pilot being specifically informed. While the Safety Board recognizes that the FAA is concerned about radio frequency congestion in busy terminal areas, any control procedure which effects a change in the responsibility for providing terrain clearance must be communicated and clearly understood by both pilots and controllers. If radar service is terminated, the crew should be so informed. Then they will be prepared to resume the responsibility for navigation which was vested in the controller while the flight was classified and handled as a radar arrival….” (NTSB 1975, 34)

“In summary, this accident resulted from a combination of conditions which included a lack of understanding between the controller and the pilot as to which air traffic control criteria were being applied to the flight while it was operating in instrument meteorological conditions in the terminal area. Neither the pilot nor the controller understood what the other was thinking or planning when the approach clearance was issued. The captain did not react correctly to his own doubt about the line of action he had selected because he did not contact the controller for clarification. The action of the other air carrier pilot who questioned the clearance he received about 1/2 hour before the accident is the kind of reaction that should be expected of a pilot suddenly confronted with uncertainty about the altitude at which he should operate his aircraft.

“The Board again stresses that it is incumbent upon air carrier management to assure the highest possible degree of safety through an assertive exercise of its operational control responsibility. This management function must assure that flightcrews are provided with all information essential to the safe conduct of flight operations. Furthermore, the air carrier must assure that its flightcrews are indoctrinated in the operational control precept and that during flight the final and absolute responsibility for the safe conduct of the flight rests solely with the captain as pilot-in-command regardless of mitigating influences which may appear to dilute or derogate this authority.

“Whereas the air carriers and the pilots are expected to perform their services with the highest degree of care and safety, this same high level of performance must be expected from the management of the air traffic control system and the controller. The instant case provides a classic and tragic example of a pilot and controller who did not fully comprehend the seriousness of the issuance and acceptance of a clearance which was not precise or definitive. The pilot should question a clearance which leaves any doubt as to what course of action should be followed. The Board also believes that it is incumbent upon the controller to ascertain beyond a doubt that the terminology of a clearance conveys the intent to the pilot, and to question the pilot if there is any doubt that he has understood it and is initiating actions compatible with the intent of the clearance.” (NTSB 1975, 35-36)

“The FAA was not responsive to the long standing, expressed needs and concerns of the users of the Air Traffic Control System with regard to pilot/controller responsibilities pursuant to the issuance of an approach clearance for a nonprecision approach. Furthermore, the FAA did not provide users of the Air Traffic Control System with sufficient information regarding the services provided by the system under specific conditions.” (NTSB 1975, 39)

“Subsequent to the accident the FAA amended 14 CFR 91.75(a) to reemphasize that “If a pilot is uncertain of the meaning of an ATC clearance, he shall immediately request clarification from ATC.” (NTSB 1975, 36)

“Subsequent to the accident, the FAA has taken several actions in an effort to prevent recurrence of this type of accident.

1. The FAA has directed that all air carrier aircraft be equipped with a ground proximity warning system by December 1975.

2. The FAA has revised the provisions of 14 CFR 91 with regard to pilot responsibilities and actions after receiving a clearance for a nonprecision approach.

3. The FAA has established an incident reporting system which is intended to identify unsafe operating conditions in order that they can be corrected before an accident occurs.

4.The FAA has changed its air traffic control procedures to provide for the issuance of altitude restrictions during nonprecision instrument approaches.

5. The FAA is installing a modification to the ARTS III system that will alert air traffic controllers when aircraft deviate from predetermined altitudes while operating in the terminal area.” (NTSB 1975, 40-41) ….

“McAdams and Haley, Members, dissenting:

“We do not agree with the probable cause as stated by the majority. In our opinion, the probable cause was the failure of the controller to issue altitude restrictions in accordance with the Terminal Air Traffic Control Handbook 7110.8C, paragraph 1360(c), and the failure of the pilot
to adhere to the minimum sector altitude as depicted on the approach plate or to request clarification of the clearance. As a result, the pilot prematurely descended to 1, 800 feet.

“The flight was a radar arrival and, therefore, entitled to altitude protection and terrain clearance. If the controller, as required by the then-existing procedures for radar arrivals, had issued altitude restrictions with the approach clearance or had deferred the clearance, the accident probably would not have occurred. On the other hand, if the pilot had either maintained the minimum sector altitude of 3,300 feet as depicted on the approach plate, or requested clarification of the clearance, there would not have been an accident.

“The majority states (p. 32):

“The Board concludes that based on the criteria in 7 110.8C the system allowed for the classification and handling of Flight 514 as a nonradar arrival. The Board, however, believes that the flight should have been classified and handled as a ‘radar arrival. ‘ ”

“This statement cannot be reconciled with the probable cause as stated by the majority. If the majority believes that under all the circumstances the flight should have been classified and handled as a radar arrival, then the flight was in fact a radar arrival and the probable cause should so state, It is not possible to determine from the majority opinion whether Flight 514 was a radar or a nonradar arrival.

“The Board attributes the failure of the controller to handle the flight as a radar arrival to be a terminology difficulty between pilots and controllers, There was no terminology difficulty. The plain fact of the matter is that the controller simply did not treat the flight as a radar arrival as he
should have. All the criteria of paragraph 1360 for a radar arrival were present. Neither the pilot nor the controller had terminology difficulties. The pilot assumed he was a radar arrival and would be given altitude restrictions if necessary. Not having received such restrictions, he initiated a descent to 1,800 feet….

“In any event, we can only conclude that, in not handling the flight a radar arrival, the Dulles controller did not properly apply the provisions of the controller’s handbook. Furthermore, it appears from the testimony of other controllers at the hearing that they would have handled the flight a similar manner, which may in turn indicate a lack of understanding comprehension by controllers generally regarding the application of paragraph 1360….

“The real issue in this accident is not one of inadequacy of terminology or lack of understanding between controllers and pilots. Rather, it is a failure on the part of both the controllers and pilots to utilize the ATC system properly and to its maximum capability.” (NTSB 1975, 45-52)

SEMP: “At 11:10 a.m., December 1, 1974, TWA Flight 514, a Boeing 727 flying in bad weather, crashed into the wooded slope of a 1,725-feet mountain about 25 nautical miles northwest of Dulles International Airport (first opened in 1962), Washington, D.C., killing all 92 people aboard (85 passengers and 7 crew members) and destroying the plane. (1) It was the worst air disaster of 1974.

“The crash not only extinguished 92 precious lives, it also severed the main underground phone line to the federal government’s classified underground complex designed to serve as a headquarters for high government officials in the event of nuclear war, and divulged to the American public the hitherto unknown existence of the facility.

“The secret complex was one and one-half miles from the crash site. “People who went to the rescue noticed much more than the federal government would have preferred,” writes former FEMA Director Julius W. Becton, Jr. “The rescue crews found it mighty strange that cars were parked in the middle of nowhere near the mountaintop, and that was how the cover was blown for Mouth Weather, which is a classified, underground shelter for a sizeable number of people near the Pennsylvania border.” ….

“Flight 514 was a regularly scheduled flight from Indianapolis, Indiana, to Washington, D.C., with an intermediate stop at Columbus, Ohio…. Flight 514 departed Columbus at 10:24. Twelve minutes later, the Cleveland Air Route Traffic Control Center informed the crew of Flight 514 that “no landings were being made at Washington National Airport because of high crosswinds, and that flights destined for that Airport were either being held or being diverted to Dulles National Airport. At 10:42, Cleveland Air Route Traffic Control cleared Flight 514 to Dulles via the Front Royal VOR, and to maintain flight level….

“The controller subsequently testified that he noticed on the radarscope that the flight’s altitude was about 2,000 feet just before he called them. The flight data recorder readout indicated that after the aircraft left 7,000 feet, the descent was continuous with little rate variation until the indicated altitude was about 1,750 feet…The accident occurred on the west slope of Mount Weather, Virginia, about 25 nautical miles from Dulles, at an elevation of about 1,670 feet.” ….

“The wreckage covered an area about 900 feet long and 200 feet wide. “The evidence of first impact was trees whose tops were cut off about 70 feet above ground. The elevation at the base of the trees was 1,650 feet. After about 500 feet of travel through the trees, the aircraft struck a rock outcropping at an elevation of about 1,675 feet. Numerous heavy components of the aircraft were thrown forward of the outcropping. “The wing flaps, wing leading edge devices, and the landing gear were retracted.” The crash was not a survivable event….”(SEMP, “Horrific TWA Crash…” November 20, 2008)

Sources

Faith, Nicholas. Black Box: Why Air Safety is no Accident. London: Boxtree, 1996.

National Transportation Safety Board. Aircraft Accident Report. Trans World Airlines, Inc. Boeing 727-231, N54328, Berryville, Virginia, December 1, 1974 (NTSB-AAR-75-16). Washington, DC: NTSB, Nov 26, 1975. At: http://amelia.db.erau.edu/reports/ntsb/aar/AAR75-16.pdf

Suburban Emergency Management Project. “Horrific TWA Crash Inadvertently Exposed Fed’s Classified Mount Weather Installation, 1974.” Biot Report #565, November 20, 2008. Accessed at: http://www.semp.us/publications/biot_reader.php?BiotID=565