CircumFlightN1972M accident
NTSB CEN14LA196 · 2014-04-11 · West Chicago, IL · near DPA
Docket — crew, injuries and powerplant
Summary
The commercial pilot was conducting a business flight and was preparing to land the airplane. He reported that, during the landing approach, he lowered the landing gear, which resulted in a gear down-and-locked indication. He subsequently made a smooth landing, but as soon as the nose gear touched down, the airplane "yanked severely to the left." He attempted to maintain directional control, but the airplane exited the left side of the runway into grass, the right wing contacted an airport sign, and the landing gear collapsed. A postaccident examination revealed that the nose gear actuator attachment to the engine mount was fractured in two places. A metallurgical examination revealed that the fracture surfaces and deformation patterns were indicative of overstress separations at both locations. No preexisting cracking was noted. The investigation could not determine whether the overstress damage occurred during the accident landing or previous landings. The airplane manufacturer had previously issued a service bulletin (SB), which recommended that an initial inspection of the engine mount for cracks in the area of the nose gear actuator attachment be accomplished at 740 hours time in service (TIS). However, the airplane only had 550 hours TIS at the time of the accident; therefore, it had not undergone the initial inspection recommended by the SB. Following the accident, the manufacturer reduced the initial inspection time to 200 hours TIS and redesigned the engine mount.
Full narrative
On April 11, 2014, about 1607 central daylight time, N1972M, a Piper Mirage PA-46-350P airplane, experienced a landing gear collapse following a loss of directional control on landing at the DuPage County Airport (DPA), West Chicago, Illinois. The commercial pilot and passenger were not injured. The airplane received substantial damage to the firewall and wings. The airplane was registered to General Leasing of Michigan LLC and was operated by the pilot/owner as a 14 Code of Federal Regulations Part 91 business flight. Visual meteorological conditions prevailed for the flight, which operated on an instrument flight rules flight plan. The flight originated from the DuPont-Lapeer Airport (D95), Lapeer, Michigan, about 1430.
The pilot stated that he received a gear down and locked indication when he lowered the landing gear and during the approach. He stated the landing was smooth and as soon as the nose gear touched down, the airplane "yanked severely to the left." He attempted to maintain control, but the airplane ultimately traveled into the grass off the left side of the runway. The right wing contacted an airport sign and the landing gear collapsed.
A postaccident examination revealed that the nose gear actuator attachment was fractured in two places. Further examination revealed that the fracture surfaces and deformation pattern were indicative of overstress separations at both locations. No preexisting cracking was noted.
The nose gear position switch is located on the nose gear actuator. As the nose gear retracts, the steering linkage separates from the gear so that movement of the rudder pedals does not move the position of the nose gear. The nose gear is designed to rotate 90 degrees to stow in the retracted position. The nose gear actuator is bolted to the lower aft engine mount, which is constructed of welded tubes. The nose gear actuator extends from the engine mount and attaches to the nose landing gear.
Piper Aircraft Service Bulletin 1103D dated February 2, 2011, was current at the time of the accident. The service bulletin addressed engine mount inspection intervals for PA-46-310P, PA-46-350P and PA-46-350T airplanes as a result of several accidents and incidents where cracks developed on the engine mount in the area of the nose gear actuator attachment. For the accident airplane, the service bulletin required the first engine mount inspection to be accomplished at 740 hours of time in service, and thereafter at a frequency not to exceed 100 hours of time in service. The accident airplane had 550 hours of time in service when the accident occurred, thus it was 190 hours below the initial inspection time requirement.
On June 5, 2014, subsequent to the accident, Piper Aircraft updated the service bulletin reducing the initial inspection time to 200 hours of time in service and thereafter at intervals not to exceed 100 hours of time in service. The service bulletin also stated that Piper Aircraft had redesigned the engine mount and if the new engine mount was installed, the inspections could be eliminated.
On April 8, 2010 the National Transportation Safety Board had issued Safety Recommendation A-10-44 and -45, suggesting that the Federal Aviation Administration: 1) require repetitive inspections for fatigue cracks on all PA-46-310 and -350P airplanes, and 2) require Piper Aircraft to redesign the PA-46-310 and -350P engine mounts so that they would not be susceptible to fatigue cracking.
Probable cause
The failure of the nose gear actuator attachment to the engine mount due to overstress, which resulted in the loss of directional control during landing. The National Transportation Safety Board determined the probable cause of this accident.
Circumstances
- Event type
- Accident
- Highest injury
- None
- Weather conditions
- Visual Meteorological Cond
- Light condition
- Day
- Sky condition
- BKN
- Ceiling (ft)
- 10000
- Visibility (sm)
- 10
- Wind direction
- 240
- Wind speed (kt)
- 14
- Nearest airport
- DuPage County Airport
- Distance from field
- 0.0
- Airport elevation
- 759
Aircraft
| Registration | Make | Model | Damage | FAR part |
|---|---|---|---|---|
| N1972M | — | — | SUBS | 091 |
Sequence of events
| # | Occurrence | Phase |
|---|---|---|
| 1 | Landing-landing roll Aircraft structural failure defining | Cruise |
| 2 | Landing-landing roll Loss of control on ground | Cruise |
| 3 | Landing-landing roll Collision with terr/obj (non-CFIT) | Cruise |
| 4 | Landing-landing roll Landing gear collapse | Cruise |