NTSB Identification: DFW08FA036.
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Accident occurred Friday, November 23, 2007 in Mesquite, TX
Probable Cause Approval Date: 08/28/2008
Aircraft: Cessna A150K, registration: N8301M
Injuries: 1 Fatal,1 Serious.

NTSB investigators either traveled in support of this investigation or conducted a significant amount of investigative work without any travel, and used data obtained from various sources to prepare this aircraft accident report.

Witnesses related that the airplane had been refueled prior to departing on an instructional flight. Shortly after departure, during the initial climb, a witness saw the airplane in a steep turn, followed by the nose dropping, and the airplane entering a spin prior to impact. A flight instructor, familiar with accident type airplane, also saw it prior to impact, and said he thought the wing flaps were extended approximately 20 to 30 degrees. During the wreckage examination, the wing flap indicator was found damaged, and read about 28 degrees down. The flap actuator jackscrew measurement equated to flaps extended about 30 degrees. A separate electrical supply was connected to the flap motor, bypassing the internal electrical circuits, and the motor was energized. The jackscrew successfully raised and lowered the flaps. The fuse for the electric flap motor was removed from the instrument panel. Beneath the fuse holder, the instrument panel was marked: "FLAPS SLO-BLO." The fuse had the markings: "BUSS AGS 10" on the side. An examination of the fuse revealed that it was blown (nonfunctional). The Operators Manuel states: "Note: A special "SLO-BLO" fuse protects the wing flaps circuit. If this fuse is replaced, care should be taken to assure that the replacement fuse is of the proper type and capacity. A "SLO-BLO" fuse is identified by an integrally mounted spring encircling the fuse element." Additionally, the manual calls for a SLO-BLO fuse rated for 15 amps. On flap operation, the following is noted; "Flap deflections of 30 and 40 degrees are not recommended at any time for take-off." An examination of the engine did not reveal any preimpact mechanical anomalies that would have prevented normal operation. The gross weight of the airplane was estimated to be approximately 1,770 pounds, or about 170 pounds over the allowable gross weight.

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

The flight instructor's failure to maintain sufficient airspeed to avoid a stall during takeoff-initial climb. Factors contributing to the accident are the instructor's decision to takeoff with excessive flaps, the improper maintenance replacement of the flap fuse, and the inability to raise the flaps due to a nonfunctional flap fuse.

Full narrative available

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