FAA Cautions Pilots After The Crash Of A Beechcraft Duke Aircraft (BE-60)

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FAA Cautions Pilots After The Crash Of A Beechcraft Duke Aircraft (BE-60) By Daniel Baxter

		February 8, 2011 - The FAA is cautioning pilots and operators to properly check flap operation prior to takeoff on the Beechcraft Duke (BE-60) by performing a flap prefight check. This comes after the crash of a Beechcraft Duke (BE-60) model airplane, N105PP that crashed just after takeoff killing the pilot. The initial impact point was in a grassy area, left of runway 27, near taxiway F. On December 4, 2007, a Beechcraft Duke (BE-60), N105PP, was destroyed when it crashed after takeoff from New Castle Airport (ILG), New Castle, Delaware. The pilot was killed and the aircraft was destroyed.

No flight plan had been filed for the flight to Lehigh Valley International Airport (ABE), Allentown, Pennsylvania. The investigation revealed that the flap actuators may have undergone improper maintenance practices. One actuator was fully retracted and the other was fully extended which may have contributed to the accident. The pilot, age 40, held a private pilot certificate with airplane single engine land, airplane multi-engine land, and instrument airplane ratings. In excerpts from the pilot's logbook, he indicated 1,080 hours of total flight time, with 425 hours in multiengine airplanes. The pilot completed Beech 60 recurrent training on October 16, 2007. The FAA is recommending that pilots and operators of the Duke (BE-60) should properly verify the full operation of their wing flaps prior to takeoff in accordance with the Before Takeoff procedures. The Pilot?s Operating Manual reads ?Flaps ? Check operation and set.? This can include a visual verification of flap position and corresponding agreement with cockpit indicators. If improper operation is suspected, they should visually inspect each flap position. According to an airport employee, a certificated flight instructor, who was at the time in an airport vehicle near the approach end of runway 27, observed the Beechcraft Duke Aircraft in the engine run-up area. The flight instructor reported the run-up appeared normal, he did notice the airplane's flaps were extended. After the run-up, the airplane taxied toward the runway with both flaps still extended.

The New Castle Airport tower controller reported that he cleared the airplane to depart from runway 27, and based on previous communications, expected the pilot to turn right, to the north after departure. After takeoff, the airplane's initial climbout was "normal" until it was 50 to 70 feet in the air.

The airplane then entered a "slight" left bank, and the controller asked the pilot if he still intended turning to the north. The pilot responded, "five papa papa," and the transmission "cut off." The airplane then made a "steep climb" to 250 to 300 feet, and as it climbed, the angle of bank appeared to increase. As the airplane reached the top of its climb, the nose "came down and went straight into the ground." Upon impact, the airplane became engulfed in flames.

According to the Duke 60 Series Maintenance Manual, "the flaps consist of a section on each wing driven by a single electric motor. A flexible drive shaft extends from the motor assembly to a jackscrew actuator for each section." In addition, limit switches are installed on the outboard side of the inboard left wing flap track to stop flap travel at 0 degrees (full up), 15 degrees (approach), and 30 degrees (full down), depending on the position of the flap control switch. "To indicate the position of the flaps...an adjustable flap position transmitter is installed on the flap actuator in the right wing. An indicator on the right subpanel provides a visual indication of the flap position."

The airplane's logbooks were not located. A mechanic who had previously worked on the airplane recalled the pilot mentioning that the flap motor had been worked on in North Carolina; however, an FAA check of maintenance facilities in that state could not confirm that any work was done. In addition, the pilot's wife and his business associates could also not locate any receipts or work orders referring to flap system maintenance. The mechanic also thought that the airplane's latest annual inspection occurred on October 15 or 16, 2007. Estimated operating time since then, based on the pilot's logbook, was about 19 hours.

The flap drive mechanism was examined at Hawker-Beechcraft facilities, Wichita, Kansas, under FAA oversight. The examination confirmed that the left flap actuator was retracted and the right flap actuator was extended. Further examination revealed that the left flap drive cable was separated from the flap motor, and the actuator attachment fixture socket was disconnected from the hex nut fitting that was still attached to the 90-degree drive assembly. All right side actuator system components were intact except that the key on the drive shaft inside the right 90-degree drive assembly adapter was fractured and the drive shaft could be turned freely without engaging the actuator.

The key was found inside the keyway. Key fracture surfaces were examined stereoscopically and found to be characteristic of shear overload, "indicating torsional shear with the output drive shaft turning a clockwise direction." The metallurgical report also noted that the direction of the overload corresponded to the "flap extension direction" and that "metallurgical forensic evidence was not conclusive as to when the fracture occurred."

Lubricants found on the internal screw shafts and pistons were covered in a dark, grease-like substance. A review of applicable engineering drawings indicated that the parts were supposed to be lubricated with lubricating oils, not grease.

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