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Safety Recommendation Details

Safety Recommendation A-81-122
Details
Synopsis: ON JUNE 19, 1980, A MCDONNELL DOUGLAS DC-9-80, N1002G, SKIDDED OFF THE RIGHT SIDE OF RUNWAY 21R WHILE ATTEMPTING A SIMULATED HYDRAULIC SYSTEMS INOPERATIVE LANDING AT THE YUMA INTERNATIONAL AIRPORT, YUMA, ARIZONA. THE AIRCRAFT CAME TO REST ABOUT 6,700 FEET BEYOND THE LANDING THRESHOLD OF THE RUNWAY. THE AIRCRAFT WAS DAMAGED SUBSTANTIALLY; HOWEVER, THE THREE FLIGHTCREW MEMBERS WERE NOT INJURED. THERE WERE NO PASSENGERS. THE PURPOSE OF THE FLIGHT WAS TO DEMONSTRATE THAT THE AIRCRAFT COULD BE FLOWN AND LANDED SAFELY WITH A COMPLETE FAILURE OF ITS HYDRAULIC SYSTEMS TO DEMONSTRATE COMPLIANCE WITH A SPECIAL CONDITION TO THE PROVISIONS OF 14 CFR 25. (FOR MORE INFORMATION READ NTSB-AAR-81-16.)
Recommendation: THE NTSB RECOMMENDS THAT THE FEDERAL AVIATION ADMINSTRATION: ENSURE THAT PHASE I, II, AND III SIMULATOR REQUIREMENTS FOR OTHER MODEL AIRCRAFT AS DEFINED IN 14 CFR 121, APPENDIX H, SPECIFICALLY INCLUDE THE REPRESENTATIVE DEGRADATION OF DIRECTIONAL CONTROL ASSOCIATED WITH THE EFFECT OF REVERSE THRUST ON THE AERODYNAMIC CONTROL SURFACES IF THE SIMULATED AIRCRAFT HAS SUCH CHARACTERISTICS FOR NORMAL AND ABNORMAL CONFIGURATIONS OR SYSTEMS CONDITION, AND REVISE ADVISORY CIRCULAR 121-14C ACCORDINGLY.
Original recommendation transmittal letter: PDF
Overall Status: Closed - Unacceptable Action
Mode: Aviation
Location: Yuma, AZ, United States
Is Reiterated: No
Is Hazmat: No
Is NPRM: No
Accident #: LAX80FA111
Accident Reports: McDonnell Douglas Corporation, DC-9-80, N1002G
Report #: AAR-81-16
Accident Date: 6/19/1980
Issue Date: 9/15/1981
Date Closed: 10/3/1988
Addressee(s) and Addressee Status: FAA (Closed - Unacceptable Action)
Keyword(s):

Safety Recommendation History
From: NTSB
To: FAA
Date: 10/3/1988
Response: This is in reply to your recent letter on National Transportation Safety Board's Recommendations A-81-106, -109, and -122, in which we requested the FAA to require flight simulators to incorporate correct stability and control characteristics when reverse thrust is used during landings. This would include characteristics in both normal and abnormal flight regimes, as pointed out in your letter. The Safety Board understands that flightcrews are generally trained not to use asymmetric reverse thrust in conditions such as those which caused this accident. The Safety Board's investigation did consider whether the pilot's decision to use reverse thrust was or was not correct, as discussed in the accident report. It is also understood that flight testing in these potentially hazardous maneuvers is not a requirement of the flight test program in actual aircraft. As the simulators must therefore be programmed using mathematical predictions validated by what data is available, the simulators may have a degree of inaccuracy. However, this does not mean that this is an inappropriate condition to include in the simulator programming. On the contrary, this gives the pilot who is training in the simulator what may be his best and only chance to make this mistake without causing a catastrophe. Therefore, we believe that we must insist that the use of the words "Require" as used in Safety Recommendations A-81-106 and -109 and "Ensure" as used in Safety Recommendation A-81-122 are appropriate terms. While we note and appreciate the fact that the FAA will revise AC 120-40A, "Airplane Simulator and Visual System Evaluation," to incorporate a reverse thrust objective test for advanced simulators, we do not consider this to be an acceptable alternate action to the regulatory action suggested by the above safety recommendations. Based on this review, we have classified Safety Recommendations A-81-106, -109, and Data Source: NTSB Recommendations to FAA and FAA Responses -122 as "Closed--Unacceptable Action."

From: FAA
To: NTSB
Date: 6/20/1988
Response: ON MAY 11, 1987 THE NATIONAL SIMULATOR PROGRAM MANAGER SENT A LETTER TO ALL OPERATORS/SPONSORS OF ADVANCED SIMULATORS FOR AIRPLANES WHICH POTENTIALLY DISPLAY DEGRADATION OF AERODYNAMIC CONTROL EFFECTIVENESS WITH INCREASING REVERSE THRUST LEVELS TO ESTABLISH A SCHEDULE FOR INCORPORATING APPLICABLE DATA INTO THE RESPECTIVE SIMULATORS. I (ALLAN MCARTOR) HAVE ENCLOSED A COPY OF THE LETTER FOR THE BOARD'S INFORMATION. I WOULD LIKE TO POINT OUT...THE PRESENCE OF THESE DATA WILL PROVIDE ONLY MINIMUM, IF ANY, TRAINING VALUE. THE AIRPLANE ACCIDENT...OCCURRED...SIMULATING A COMPLETE LOSS OF HYDRAULIC SYSTEMS. ALTHOUGH THE FAA BELIEVES THAT THE PROCEDURES USED BY THE TEST PILOT WERE IN AN EFFORT TO EXPLORE THE BOUNDARIES OF DIRECTIONAL CONTROL CAPABILITY...THEY ARE EXPRESSLY WARNED AGAINST IN FLIGHT TRAINING PROGRAMS FOR ALL AIRPLANE TYPES. FLIGHTCREWS...ARE TRAINED TO IMMEDIATELY SELECT "REVERSE IDLE" AT THE FIRST INDICATION OF ANY YAWING...THIS TRAINING IS PREDOMINATELY APPLICABLE TO OPERATIONS ON WET OR ICY RUNWAYS. ALTHOUGH THE PILOT MAY NOT KNOW THE REASON FOR THE PROBLEM, HE/SHE HAS BEEN TRAINED IN THE SOLUTION... ADDITIONALLY, THE FAA IS NOT IN A POSITION TO REQUIRE CURRENTLY CERTIFICATED AIRPLANES TO BE FLIGHT TESTED UNDER THESE POTENTIALLY DANGEROUS CONDITIONS. AS A RESULT, THE DATA USED FOR PROGRAMMING THE SIMULATOR FOR THIS CONDITION MAY, IN MANY CASES, BE ONLY PREDICTED OR MATHEMATICALLY DERIVED. ANY USE...MAY BE INACCURATE AND, THEREFORE, INAPPROPRIATE. I (ALLAN MCARTOR) BELIEVE THAT THE FAA HAS MET THE INTENT OF THESE SAFETY RECOMMENDATIONS (A-81-106 & -109), AND I URGE THE SAFETY BOARD TO CLASSIFY THESE SAFETY RECOMMENDATIONS AS "CLOSED". THE FAA IS WORKING WITH INDUSTRY TO REVISE AVIATION CIRCULAR (AC) 120-40A, AIRPLANE SIMULATOR AND VISUAL SYSTEM EVALUATION. IT IS ANTICIPATED THAT THIS REVISED AC WILL BE ISSUED BY DECEMBER 31, 1988.

From: NTSB
To: FAA
Date: 4/13/1988
Response: This is a two part recommendation. We trust that the first part is being treated along with Safety Recommendations A-81-106 and A-81-109, and will be addressed in your next response. We are pleased that the FAA is reviewing a draft Advisory Circular (AC) 120-40A, Airplane Simulator and Visual System Evaluation which will incorporate a reverse thrust objective test for advanced simulators. Because of the slow progress, this recommendation also remains classified as "Open--Unacceptable Action."

From: FAA
To: NTSB
Date: 1/14/1988
Response: ENSURE THAT PHASE I, II, AND III SIMULATOR REQUIREMENTS FOR OTHER MODEL AIRCRAFT AS DEFINED IN 14 CFR 121, APPENDIX H, SPECIFICALLY INCLUDE THE REPRESENTATIVE DEGRADATION OF DIRECTIONAL CONTROL ASSOCIATED WITH THE EFFECT OF REVERSE THRUST ON THE AERODYNAMIC CONTROL SURFACES IF THE SIMULATED AIRCRAFT HAS SUCH CHARACTERISTICS FOR NORMAL AND ABNORMAL CONFIGURATIONS OR SYSTEMS CONDITION, AND REVISE ADVISORY CIRCULAR 121-14C ACCORDINGLY.

From: NTSB
To: FAA
Date: 10/13/1987
Response: Investigation of the subject accident disclosed that the effectiveness of the primary sources of directional control, i.e., the vertical stabilizer and rudder, were substantially degraded with application of reverse thrust. It was further disclosed that the airplane configuration and crew procedures established for this FAA certification test were not adequate to assure that the pilot could maintain directional stability and control for stopping the airplane in a reasonable distance. In these three recommendations we essentially requested the FAA to require flight simulators to incorporate correct stability and control characteristics when reverse thrust is used during landings. We are pleased to note that the FAA will revise AC 120-40A, Airplane Simulator and Visual System Evaluation to incorporate a reverse thrust objective test for advanced simulators. However, these recommendations are now 6 years old and we see little in the FAA's response to assure us of their satisfactory resolution within the next 2 or 3 years. We request that the FAA address each of these recommendations separately and inform the Safety Board as to what specifically has been accomplished Data Source: NTSB Recommendations to FAA and FAA Responses thus far, and what plans are underway by the FAA to take the recommended regulatory action. Pending your further response, these recommendations are classified as "Open--Unacceptable Action."

From: FAA
To: NTSB
Date: 5/6/1987
Response: THE FAA IS REVISING AC 120-40A, AIRPLANE SIMULATOR AND VISUAL SYSTEM EVALUATION, TO INCORPORATE A REVERSE THRUST OBJECTIVE TEST FOR ADVANCED SIMULATORS. THE TEST WILL REQUIRE VERIFICATION OF A REPRESENTATIVE DEGRADATION OF DIRECTIONAL CONTROL ASSOCIATED WITH THE EFFECT OF SYMMETRIC AND/OR ASYMMETRIC REVERSE THRUST ON AERODYNAMIC CONTROL SURFACES FOR AIRPLANES WITH REAR POD-MOUNTED ENGINES IN BOTH NORMAL AND ABNORMAL CONFIGURATIONS OR SYSTEM CONDITIONS. ALSO, A SUBJECTIVE EVALUATION OF THE STABILITY AND CONTROL CHARACTERISTICS WITH THE USE OF REVERSE THRUST ON AIRPLANE SIMULATORS WITH REAR POD-MOUNTED ENGINES WILL ALLOW A QUALITATIVE ASSESSMENT BY THE NATIONAL SIMULATOR EVALUATION TEAM MEMBER IN ACCORDANCE WITH THE REPRESENTATIVE FIGURES ESTABLISHED BY MCDONNELL DOUGLAS CORPORATION FOR REDUCED RUDDER EFFECTIVENESS WITH INCREASING SYMMETRIC REVERSE THRUST LEVELS. THE ABOVE TESTS WILL BE INCLUDED IN THE REVISED AC AND WILL BE EVALUATED FOR BOTH INITIAL AND RECURRENT ADVANCED SIMULATOR QUALIFICATION. IN ADDITION, OPERATORS OF THOSE ADVANCED SIMULATORS, WHICH SHOULD DISPLAY THIS REPRESENTATIVE DEGRADATION OF DIRECTIONAL CONTROL ASSOCIATED WITH THE EFFECT OF INCREASING REVERSE THRUST LEVELS, WILL BE NOTIFIED OF THIS FORTHCOMING REQUIREMENT AND WILL BE REQUESTED TO SUBMIT TO THE NATIONAL SIMULATOR PROGRAM MANAGER THEIR PROPOSAL FOR INCORPORATING THE APPLICABLE FLIGHT TEST DATA CONTAINED IN MCDONNELL DOUGLAS' REPORT MDC-J9005 INTO THEIR RESPECTIVE SIMULATORS. I WILL PROVIDE THE BOARD WITH A COPY OF THE REVISED AC AS SOON AS IT IS ISSUED.

From: NTSB
To: FAA
Date: 2/2/1987
Response: The FAA's last letter on this subject, dated January 26, 1984, indicated that efforts were being made to comply with the intent of these recommendations. In our evaluation of the FAA's letter, we stated that while the FAA's planned actions were acceptable, we believed that all of the necessary data were available and that the FAA should expedite its actions. The subject recommendations were all classified as "Open--Acceptable Action," in our letter of May 29, 1984. The Safety Board now notes that two more years have passed without any further response from the FAA. More importantly, the Safety Board is unaware of any further action being taken to correct the safety issue involved. Therefore, the Safety Board has now classified Safety Recommendations A-81-106, A-81-109, A-81-122, and A-81-123 as "Open-- Unacceptable Action," and requests that you inform the Board of the actions now being taken to comply with these recommendations.

From: FAA
To: NTSB
Date: 1/26/1984
Response: FAA LETTER: THE FAA'S NATIONAL SIMULATOR EVALUATION TEAM UNDERTOOK AN INDEPTH EVALUATION OF THE DC-9 AND B-727 TRAINING SIMULATORS OF WHICH ONLY ADVANCED SIMULATORS WERE CONSIDERED. THE RESULTS OF THE SIMULATOR TEAM EVALUATION CAN BE CATEGORIZED INTO THREE MAJOR FINDINGS AS FOLLOWS: (1) NO REDUCTION IN RUDDER EFFECTIVENESS VERSUS REVERSE ENGINE THRUST IS MEASURABLE. THIS PARTICULARLY TRUE OF DC-9 SIMULATORS. (2) THE RUDDER EFFECTIVENESS OF SOME SIMULATORS IS UNPREDICTABLE, UNEXPLAINABLE, AND NOT CHARACTERISTIC OF WHAT WOULD BE EXPECTED OF THE AIRCRAFT. THE RATE OF TURN IN SOME SIMULATORS ACTUALLY CHANGED SIGN (DIRECTION) AFTER A FEW SECONDS OF REVERSE THRUST APPLICATION AGAINST A FULL RUDDER INPUT. (3) SOME OPERATORS HAVE ATTEMPTED TO MODEL THEIR OWN REVERSE THRUST CHARACTERISTICS FROM FLIGHT TEST DATA. WHILE THIS CAUSES PERFORMANCE SIMILAR TO THAT EXPECTED, THESE MODELS DO NOT HAVE THE ENDORSEMENT OF THE AIRFRAME MANUFACTURER; THEREFORE, THEIR FIDELITY CANNOT BE GUARANTEED. IT IS APPARENT FROM THESE FINDINGS THAT THERE IS NO CONSISTENCY IN THE SIMULATOR PERFORMANCE THROUGHOUT THE INDUSTRY FOR THIS PARTICULAR EFFECT. IF EFFECTIVE TRAINING IS TO BE ACCOMPLISHED, THEN THE FIRST STEP WOULD BE TO ACQUIRE THE NECESSARY DATA AND THEN DEVELOP THE MATHEMATICAL MODELS WITH SUFFICIENT FIDELITY TO PROVIDE AN EFFECTIVE BASIS FOR TRAINING FOR THE DC-9 AND B-727 AIRPLANES. 14 CFR 121, APPENDIX H, REQUIRES THAT ADVANCED SIMULATORS INCORPORATE AERODYNAMIC PROGRAMMING TO INCLUDE: "C. GROUND HANDLING CHARACTERISTIC-STEERING INPUTS TO INCLUDE CROSSWIND, BRAKING, THRUST REVERSING, DECELERATION, AND TURNING RADIUS." WHILE DIRECTIONAL CONTROL WITH REVERSE THRUST IS NOT SPECIFICALLY ADDRESSED, IT IS IMPLIED IN THE ABOVE QUOTATION. THE NEED FOR DIRECTIONAL CONTROL WITH REVERSE THRUST IN ADVANCED SIMULATORS AND THE TRAINING VALUE TO BE DERIVED WAS, THEREFORE, RECOGNIZED IN THE DEVELOPMENT OF THE ADVANCED SIMULATION PLAN. IT WAS ALSO RECOGNIZED THAT DATA WAS NOT AVAILABLE TO PROGRAM SIMULATORS SINCE INCORPORATE NEW FEATURES IS SERIOUSLY LIMITED BY AVAILABLE QUALITATIVE EVALUATION DURING AIRPLANE CERTIFICATION. 14 CFR 121, APPENDIX H, SPECIFIES REVERSE THRUST DATA FOR AIRPLANES ON WHICH A TYPE CERTIFICATE WAS ISSUED AFTER JUNE 1, 1980. BUT TO HAVE REQUIRED SUCH DATA FOR ALL AIRCRAFT WOULD HAVE BEEN AN ECONOMIC BURDEN TO THE INDUSTRY WHICH WAS NOT WARRANTED IN VIEW OF THE TRAINING VALUE WHICH COULD BE DRIVED. FURTHER, THE CAPABILITY OF OLDER SIMULATORS TO INCORPORATE NEW FEATURES IS SERIOUSLY LIMITED BY AVAILABLE COMPUTER CAPACITY. IN THE DEVELOPMENT OF ADVISORY CIRCULAR (AC) 120-40, WHICH SUPERSEDED AC 121-14C, IT WAS CONTEMPLATED TO MAKE RUDDER EFFECTIVENESS DURING REVERSE THRUST AN OBJECTIVE TEST FOR SIMULATOR APPROVAL. IN CONSIDERATION OF THE AVAILABLE DATA, HOWEVER, TESTING WAS LIMITED TO QUALITATIVE EVALUATION. THE FAA'S EVALUATION OF ADVANCED SIMULATORS, WITH A SPECIFIC LOOK AT RUDDER EFFECTIVENESS VERSUS REVERSE ENGINE THRUST, HAS NOW BEEN COMPLETED BY THE NATIONAL SIMULATOR EVALUATION TEAM. ITS FINDINGS SHOW A LACK OF CONSISTENCY IN SIMULATOR RESPONSES AND SUGGEST THAT NEGATIVE TRAINING MAY RESULT FROM SOME OF THE SIMULATORS. BECAUSE OF THE SIMULATOR TEAM'S FINDINGS THAT THE SIMULATORS ARE NOT PROGRAMMED FOR THIS MANEUVER, THE FAA WILL CONTINUE TO WORK ON THIS AREA. IF, IN THE FUTURE, THE NECESSARY DATA CAN BE ACQUIRED AND VALIDATED FOR USE IN THE SIMULATORS, THE FAA WILL CONSIDER A CHANGE TO INCORPORATE THE MANEUVER INTO 14 CFR 121 TRAINING PROGRAMS. FOR THE PRESENT, A LETTER WILL BE SENT TO ALL APPROPRIATE FAA REGIONS TO ASSURE THAT THE DIFFICULTIES ENCOUNTERED IN THE REVERSE THRUST MANEUVER ARE PART OF THE CLASSROOM TRAINING PROGRAM.

From: NTSB
To: FAA
Date: 7/8/1982
Response: Your agreement with these recommendations and action to initiate a study of reverse thrust as it applies to training simulators is acceptable. We would appreciate being informed of the status of this study and of any decisions regarding additional reverse thrust programming. These recommendations are classified as "Open-- Acceptable Action."

From: FAA
To: NTSB
Date: 12/30/1981
Response: FAA LTR: THE FAA AGREES THAT THIS RECOMMENDATION HAS MERIT AND WILL INITIATE A STUDY ON THE EFFECT OF REVERSE THRUST AS IT APPLIES TO FLIGHT TRAINING SIMULATORS. RESEARCH ORGANIZATIONS SUCH AS NASA WILL BE CONSULTED AS PART OF THE STUDY. SHOULD THE FAA CONCLUDE THAT ADDITIONAL REVERSE THRUST PROGRAMMING IS REQUIRED IN FAA APPROVED FLIGHT TRAINING SIMULATORS, SPECIFIC REVERSE THRUST PERFORMANCE TEST CRITERIA WILL BE ADDED TO EXISTING TEST REQUIREMENTS.