NTSB Identification: FTW99LA272.
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Accident occurred Thursday, September 30, 1999 in POTEAU, OK
Probable Cause Approval Date: 12/05/2000
Aircraft: Cessna 150F, registration: N8092S
Injuries: 1 Fatal,1 Serious.

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 student pilot planned the night cross-country flight; however, the flight instructor performed the fuel calculations by using a 4-hour fuel endurance minus the student's flight time to the origination airport. The instructor determined that there was enough fuel for the flight and elected not to have the fuel tanks filled prior to the flight. During the first leg of the flight, the generator warning light illuminated. The student indicated to the instructor that he thought it was an indication problem and not a generator problem. The instructor and student elected to continue the flight, performing touch-and-go landings at two separate airports. On the third/last leg of the flight, after the instructor noticed the fuel gauges reading empty in one fuel tank and 1/4 full in the other, the student informed the instructor that his airplane only had a 3.5-hour fuel endurance. During the last leg of the flight, the electrical system failed. Due to the low fuel status, the instructor did not divert to an airport with automatic runway lighting, but continued to the original destination airport, which had a pilot controlled runway light system. The instructor attempted two approaches with no runway or aircraft lighting. On the second approach, the airplane impacted the ground and a ditch. A work order included in the maintenance records indicated that the generator 'fuses' were 'replaced' 2.5 months prior to the accident. Examination of the electrical system revealed that a 30-amp fuse was installed in the generator fuse holder, and the fuse had 'blown.' The aircraft's electrical system required a 35-amp generator fuse.

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

The instructor pilot's inadequate in-flight decision making, which resulted in the continued flight with a disabled generator and subsequent total failure of the electrical system. Factors were the installation of the inadequate generator fuse by unknown person(s), the instructor's failure to refuel the airplane prior to the flight, and the dark night conditions.

Full narrative available

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