We know of the obvious ones. Here are some flight control related reports.
NTSB Identification: CHI98LA063 . The docket is stored in the (offline) NTSB Imaging System.
14 CFR Part 91: General Aviation
Accident occurred Wednesday, December 10, 1997 in ROCKFORD, IL
Probable Cause Approval Date: 5/29/98
Aircraft: Beech 1900C, registration: N79GL
Injuries: 4 Uninjured.
The airplane had just been refurbished, and it required a maintenance flight check before being released for flight. The pilot conducted a preflight of the airplane, checking the flight controls for freedom of movement and observing aileron movement up and down, but did not 'see' or notice incorrect aileron movement. The pilot used normal takeoff procedures. During rotation, the airplane's left wing began to drop to the left. The pilot applied right aileron, but with no effect. The airplane struck the left edge of the runway in a left wing low attitude, and the left wing impacted a taxi sign. An examination of the airplane revealed that the aileron cables were incorrectly connected at the turnbuckles in the wheelwell. The aircraft maintenance manual contained the following warning: 'Visually check to assure that aileron travel responds properly to the control wheel movement. When the control wheel is turned right, the right aileron should move up and the left aileron should move down.'
The National Transportation Safety Board determines the probable cause(s) of this accident as follows:
improper installation of aileron cables by the maintenance personnel, inadequate inspection by the company's maintenance personnel of maintenance performed, and inadequate preflight by the pilot.
NTSB Identification: NYC97IA123 . The docket is stored in the (offline) NTSB Imaging System.
Scheduled 14 CFR Part 121: Air Carrier MESA AIRLINES, INC.
Incident occurred Thursday, June 19, 1997 in CLARKSBURG, WV
Probable Cause Approval Date: 4/24/98
Aircraft: Beech 1900D, registration: N165YV
Injuries: 2 Uninjured.
The pilot lowered the flaps to 35 degrees while on final approach to runway 21. He noted aileron binding as the flaps traveled to 35 degrees, and at the same time heard a snap under the floor of the cockpit. After landing the flaps were not retracted. The airplane was taxied to the terminal where it was observed that the right outboard flap panel had became detached from the flap aft roller bearings at the inboard flap track. The flap was in contact with the aileron, which interfered with aileron control. The manufacturer had published a Safety Communique during May 1997. The Communique dealt with the inspection of the outboard flap attachment brackets and aft roller bearings of Beech 1900 series airplanes. The incident airplane was scheduled to have the inspection complied with during the next 30 days. The airplane had accumulated about 3,317 flight hours and 7,069 landings. An inspection of the remainder of the operator's fleet of Beech 1900D airplanes revealed that eight additional airplanes failed the inspection criteria, but had not reached the assigned number of cycles specified in the Communique.
The National Transportation Safety Board determines the probable cause(s) of this incident as follows:
The right outboard flap detaching from the flap aft roller bearings, at the flap track, which was a result of the manufacturer's inadequate inspection program.
NTSB Identification: SEA97IA051 . The docket is stored in the (offline) NTSB Imaging System.
Scheduled 14 CFR Part 135: Air Taxi & Commuter
Incident occurred Tuesday, January 21, 1997 in SEATTLE, WA
Probable Cause Approval Date: 6/26/97
Aircraft: Beech 1900D, registration: N75ZV
Injuries: 7 Uninjured.
While on final approach, the airplane commenced a rapid, uncommanded roll to the right when the 35-degree flap setting was selected. The flying pilot (1st officer) was able to counter the roll by applying almost full opposite aileron, during which time, he felt the aileron jam momentarily and then break free. The airplane landed without further incident. An examination revealed that the inboard, aft end of the right wing outboard flap was detached from the wing flap track. This resulted in flap asymmetry and mechanical interference with the aileron. The flap track roller bearing was seized and the flap mounting bracket was torn and separated from the bearing. The bearing outer roller was loose and could be shifted axially on the bearing outer ring. This allowed the outer roller flange to wear against and eventually tear through the flap mounting bracket. The operator was not using the most recent (revised) Beech 1900D maintenance manuals at the time of the incident and the airplane had not been subjected to a detailed inspection of the flap roller brackets, roller bearings, and attachment hardware as outlined in revised sections of the manual.
The National Transportation Safety Board determines the probable cause(s) of this incident as follows:
an axial shift of the aft flap track bearing's outer roller, resulting in erosion and failure of the flap track bracket/bearing assembly. A factor relating to the incident was: inadequate inspection of the flap roller bearing/bracket assemblies.
NTSB Identification: FTW96IA080 . The docket is stored in the (offline) NTSB Imaging System.
Scheduled 14 CFR Part 135: Air Taxi & Commuter
Incident occurred Monday, December 25, 1995 in DENVER, CO
Probable Cause Approval Date: 6/6/96
Aircraft: Beech 1900C, registration: N39019
Injuries: 21 Uninjured.
During landing flare, the elevator jammed. The pilot continued the landing using elevator trim to adjust nose attitude. Investigation revealed that an elevator counterweight bolt had backed out and jammed the elevators. The aircraft was on its first trip after being painted by an outside contractor and undergoing a return-to-service inspection by the operator.
The National Transportation Safety Board determines the probable cause(s) of this incident as follows:
failure by the outside contractor to perform adequate maintenance, and failure by the operator to perform an adequate inspection.
NTSB Identification: LAX95IA142 . The docket is stored in the (offline) NTSB Imaging System.
Scheduled 14 CFR Part 135: Air Taxi & Commuter
Incident occurred Friday, March 17, 1995 in LOS ANGELES, CA
Probable Cause Approval Date: 4/19/96
Aircraft: BEECH 1900C, registration: N1568W
Injuries: 19 Uninjured.
WHILE ON FINAL APPROACH, THE AIRPLANE EXPERIENCED A RAPID, UNCOMMANDED ROLL TO THE LEFT WHEN THE 35-DEGREE FLAP SETTING WAS SELECTED. THE PILOT WAS ABLE TO COUNTER THE ROLL BY APPLYING FULL OPPOSITE AILERON AND LANDED WITHOUT FURTHER INCIDENT. AN EXAMINATION REVEALED THAT THE WING FLAPS HAD BEEN FULLY EXTENDED IN THE AFT DIRECTION, BUT THAT THE INBOARD TRAILING EDGE OF THE LEFT OUTBOARD FLAP HAD BEEN FORCED UPWARD ABOUT 3 INCHES. THE INBOARD AFT FLAP TRACK ROLLER BEARING ASSEMBLY, INCLUDING THE ATTACHING BOLT AND WASHER, HAD PULLED THROUGH THE SKIN OF THE FLAP TRACK HINGE BRACKET. AN ANALYSIS OF THE FAILED PARTS BY BEECH REVEALED THAT THE OUTER ROLLER WAS LOOSE ON THE BEARING AND COULD BE SHIFTED AXIALLY. A CIRCULAR WEAR PATTERN MATCHING THE DIAMETER OF THE OUTER ROLLER FLANGE WAS FOUND ON THE PORTION OF FLAP TRACK HINGE BRACKET WHICH HAD PULLED OUT. BEECH CONCLUDED THAT THE BEARING OUTER ROLLER HAD SHIFTED ON THE ROLLER ELEMENT BEARING AND ALLOWED THE OUTER ROLLER FLANGE TO WEAR AGAINST THE SIDE OF THE FLAP HINGE BRACKET UNTIL THE BEARING ASSEMBLY WAS PULLED OUT. THE FAILED FLAP TRACK HINGE BRACKET AND BEARING ASSEMBLY IS CONTAINED WITHIN THE INTERIOR OF THE FLAP STRUCTURE.
The National Transportation Safety Board determines the probable cause(s) of this incident as follows:
AN AXIAL SHIFT OF THE OUTER BEARING ROLLER FOR AN UNDETERMINED REASON, RESULTING IN EROSION AND FAILURE OF THE FLAP TRACK HINGE BRACKET/BEARING ASSEMBLY. FACTORS RELATING TO THE INCIDENT WERE: THE ROLLER BEARING AND ASSOCIATED BRACKET ASSEMBLY WITHIN THE INTERIOR OF THE FLAP STRUCTURE COULD NOT BE ADEQUATELY INSPECTED WITHOUT DISASSEMBLY; AND LACK OF INSPECTION CRITERIA IN THE MANUFACTURER'S MAINTENANCE MANUAL CONCERNING FLAP ROLLER/HINGE BRACKET ASSEMBLIES.
NTSB Identification: CHI95IA066 . The docket is stored in the (offline) NTSB Imaging System.
Scheduled 14 CFR Part 135: Air Taxi & Commuter
Incident occurred Thursday, January 12, 1995 in WILLISTON, ND
Probable Cause Approval Date: 8/31/95
Aircraft: BEECH 1900D, registration: N118UX
Injuries: 6 Uninjured.
DURING AN INSTRUMENT DESCENT FROM CRUISE, THE ELEVATOR TRIM CABLE FAILED. THE CREW EXPERIENCED INCREASING NOSE DOWN PITCH REGARDLESS OF INPUT. A SAFE LANDING WAS ACCOMPLISHED BY BOTH PILOTS PULLING AFT ON THE YOKE TO OVERCOME PRESSURE, AND LOWERING FLAPS AND LANDING GEAR 50 AND 20 KNOTS ABOVE THEIR RESPECTIVE OPERATING SPEEDS TO REDUCE THE TRIM FORCES AND HELP SLOW THE AIRPLANE. INSPECTION REVEALED THAT THE TRIM CABLE HAD BEEN INCORRECTLY ROUTED AROUND A CABLE GUIDE DURING INITIAL PRODUCTION, AND HAD NOT REACHED THE FIRST REQUIRED INSPECTION WHICH WOULD HAVE ALLOWED THE DISCREPANCY TO BE DISCOVERED.
The National Transportation Safety Board determines the probable cause(s) of this incident as follows:
the improper installation and inadequate quality assurance inspection of the elevator trim cable during original manufacture, which resulted in fraying and failure of the cable prior to the first routine scheduled inspection of the system.
