Status | |
Date | Thursday 27 April 1995 |
Time | 17:35 |
Type |
![]() Airbus A320-211 |
Operator | Northwest Airlines |
Registration | N331NW |
MSN | 318 |
Year of manufature | 1992 |
Engines | CFMI CFM56-5A1 |
Crew | Fatalities: 0 / Occupants: |
Passengers | Fatalities: 0 / Occupants: |
Total occupants | Fatalities: 0 / Occupants: 108 |
Aircraft damage | None |
Location | Washington, DC ![]() |
Phase | Approach |
Nature | Passenger - Scheduled |
Departure Airport | Minneapolis, MN (MSP) |
Destination Airport | |
Narrative | THE PILOT REPORTED THAT DURING THE VISUAL APPROACH TO RUNWAY 18, THE AIRPLANE ENTERED UNCOMMANDED ROLLS. A GO-AROUND WAS PERFORMED. ACCORDING TO THE PILOT, ON THE SECOND APPROACH THE AIRPLANE ONCE AGAIN EXPERIENCED AN UNCOMMANDED ROLL. THE AIRPLANE WAS LANDED. FDR DATA SHOWS THE ROLL OSCILLATIONS WITH A MAX ROLL OF 15.5 DEGREES. DURING THIS TIME THE SIDE STICK WAS BEING MOVED BACK AND FORTH TO ITS FULL TRAVEL LIMITS. THE AIRPLANE MOVEMENTS AND THE PILOT'S ACTIONS ARE CONSISTENT WITH PILOT INDUCED OSCILLATIONS (PIO). THE AIRPLANE WAS BEING LANDED IN CONF 3 (20 DEGREES OF FLAPS) WHICH MAKES THE HANDLING CHARACTERISTICS OF THE AIRPLANE 'MORE CRISP'. IN 1993 AIRBUS PUBLISHED A TEMPORARY REVISION TO THE AIRPLANE'S FLIGHT CREW OPERATING MANUAL STATING THE AIRPLANE SHOULD NOT BE LANDED IN ADVERSE WEATHER CONDITIONS (GUSTY WINDS AND TURBULENCE) IN CONF 3 DUE TO THE POSSIBILITY OF PIO. NORTHWEST AIRLINES HAD NOT INCORPORATED THIS INFORMATION IN THEIR OPERATING MANUALS. Probable Cause: the pilot's excessive use of the flight controls during the landing approach, the company's disregard of information provided by the airplane manufacturer, and the company's failure to identify a potentially hazardous conditions based on the information provided by the airplane manufacturer. Factors associated with the incident were the gusty wind conditions and the pilot's failure to land with full flaps. |
ACCIDENT INVESTIGATION
Final report
Investigating agency: NTSB
Report nr: CHI95IA138
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