NTSB Identification: IAD02LA079.
The docket is stored in the Docket Management System (DMS). Please contact Records Management Division
Accident occurred Wednesday, July 31, 2002 in WEST MIFFLIN, PA
Probable Cause Approval Date: 08/26/2003
Aircraft: Beech A-36, registration: N3869Z
Injuries: 1 Uninjured.

NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.

The pilot reported that immediately after takeoff, he lost the use of the radios and other electrical equipment. The red landing gear position light remained dimly illuminated, which indicated that the landing gear was neither securely stowed or in the down and locked position. The red alternator-out warning light was also illuminated, and the ammeter registered a discharge. The pilot contacted a 911 dispatcher on his cell phone, reported his landing intentions and proceeded toward the airport. He attempted to manually extend the landing gear with the emergency landing gear extension hand crank located behind his seat, but was unable to engage the hand crank handle. Once at the airport, the pilot flew by the control tower and a controller confirmed that the landing gear were not fully extended. The pilot then flew several traffic pattern circuits before landing on a grassy area next to a runway. Upon touchdown, the airplane continued on a straight path until it collided with a runway marker, veered left, and stopped. Examination of the alternator revealed an open rotor circuit between the F1 and F2 terminals. In addition, alternator disassembly revealed an open rotor between the rotor and slip rings. According to the airplane's pilot operating handbook, an inoperative alternator would have placed the entire electrical system operation of the airplane except engine ignition on the battery, and would have been indicated by the illumination of the ALT OUT warning light and a discharge on the ammeter.

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

The failure of the alternator. A factor was the pilot's inability to manually extend the landing gear.

Full narrative available

Index for Jul2002 | Index of months