Skip Ribbon Commands
Skip to main content
Safety Recommendation Details

Safety Recommendation A-81-108
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 ADMINISTRATION: INCORPORATE THE FOLLOWING INFORMATION IN THE DC-9 SERIES -10 THROUGH -50 TRAINING MANUALS AND PROGRAMS UNDER THE FLIGHT CONTROL AND LANDING SECTIONS: WHEN THRUST REVERSERS (LOCATED JUST FORWARD OF THE VERTICAL STABLIZER) ARE USED DURING LANDING ROLLOUT, THE EXHAUST GASES FROM THE ENGINES ARE DEFLECTED BY THE THRUST REVERSER BUCKETS IN SUCH A MANNER THAT THE FREE STREAM AIRFLOW OVER THE VERTICAL STABLIZER AND RUDDER IS BLOCKED, REDUCING THE EFFECTIVENESS OF THESE SURFACES. AT A NOMINAL AIRSPEED OF 100 KIAS, THE REDUCTION IN RUDDER EFFECTIVENESS WITH INCREASING SYMMETRIC REVERSE THRUST LEVELS IS SHOWN BELOW. ENGINE THRUST MAXIMUM RUDDER SETTING EFFECTIVENESS AVAILABLE(PERCENT)*/ FORWARD IDLE 100 REVERSE IDLE 65 1.3 EPR (REVERSE) 25 1.6 EPR (REVERSE) MINIMAL */RUDDER EFFECTIVENESS ALSO DECREASES WITH DECREASING AIRSPEED. ON A DRY RUNWAY, DIRECTIONAL CONTROL IS EASILY MAINTAINED BY DIFFERENTIAL ANTISKID BRAKING AND NOSEHWEEL STEERING. HOWEVER, UNDER ADVERSE CONDITIONS SUCH AS A SLIPPERY RUNWAY WITH RAIN, SNOW, OR ICE, WHEN CROSSWINDS REDUCE THE BRAKING EFFECTIVENESS OF THE GEAR ON THE UPWIND WING, OR WHEN A HIGH-SPEED LANDING IS MADE WITH BOTH HYDRAULICS SYSTEMS OUT (I.E., FLAPS/SLATS RETRACTED, GROUND SPOILERS, RUDDER HYDRAULIC BOOST, NOSEWHEEL STEERING ALL RENDERED INOPERATIVE, AND BRAKE ANTISKID SYSTEMS LIMITED BY HYDRAULIC ACCUMULATOR PRESSURE), THE VERTICAL STABILIZER AND RUDDER WILL BE THE PRIMARY SOURCE OF DIRECTIONAL STABILITY AND CONTROL DURING THE HIGH SPEED PORTION OF THE LANDING ROLLOUT. UNDER THESE CONDITIONS, IT IS IMPORTANT TO MAKE ALLOWANCE FOR THE ADVERSE EFFECTS OF REVERSE THRUST ON THE EFFECTIVENESS OF THE VERTICAL STABLIZER AND RUDDER.
Original recommendation transmittal letter: PDF
Overall Status: Closed - Acceptable 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: 11/2/1984
Addressee(s) and Addressee Status: FAA (Closed - Acceptable Action)
Keyword(s):

Safety Recommendation History
From: FAA
To: NTSB
Date: 11/2/1984
Response:

From: NTSB
To: FAA
Date: 5/29/1984
Response: The memorandum from the Chairman of the DC-9 Flight Standardization Board, included with your letter, directing that all DC-9 aircraft training programs incorporate the information and problems associated with reverse thrust operation, fully satisfies the Board's Safety Recommendations. These Safety Recommendations, A-81-105 and - 108, will be classified as "Closed--Acceptable Action."

From: FAA
To: NTSB
Date: 1/26/1984
Response: FAA LETTER: ENCLOSED FOR THE BOARD'S INFORMATION IS A COPY OF A MEMORANDUM FROM THE CHAIRMAN, DC-9 FLIGHT STANDARDI ZATION BOARD, THAT DIRECTS THAT ALL DC-9 AIRCRAFT TRAINING PROGRAMS INCORPORATE THE INFORMATION AND PROBLEMS ASSOCIATED WITH REVERSE THRUST OPERATION.

From: NTSB
To: FAA
Date: 7/8/1982
Response: Your referral of these recommendations for review by the DC-9 Flight Standardization Board (FSB), which is responsible for establishing FAA DC-9 minimum training requirements, is considered reasonable and responsive. These recommendations are classified as "Open--Acceptable Action," pending the results of the FSB review.

From: FAA
To: NTSB
Date: 12/30/1981
Response: FAA LTR: THE FAA CONCURS IN THIS RECOMENDATION AND AGREES THAT FLIGHT TRAINING MANUALS AND TRAINING PROGRAMS SHOULD PROVIDE FLIGHT CREWMEMBERS INFORMATION IN SUFFICIENT DETAIL THAT THEY FULLY UNDERSTAND THE HANDLING CHARACTERISTICS OF THEIR AIRCRAFT UNDER ALL CONDITIONS. THE DC-9 FLIGHT STANDARDIZATION BOARD (FSB), RESPONSIBLE FOR ESTABLISHING FAA DC-9 MINIMUM TRAINING REQUIREMENTS, WILL REVIEW NTSB RECOMMENDATIONS A-81-105 AND 108 AND TAKE ACTION TO ASSURE THAT ALL PRESENTLY ESTABLISHED DC-9 TRAINING PROGRAMS REQUIRE ADEQUATE INFORMATION AND TRAINING IN GROUND REVERSE OPERATIONS. THE SAFETY BOARD WILL BE MADE AWARE OF THE FINDINGS OF THE FSB.