Undetermined · NTSB WPR13FA368
BEECH E35 — West Yellowstone, MT
| Date | August 12, 2013 |
| Location | West Yellowstone, MT |
| Aircraft | BEECH E35 |
| Purpose of flight | Business |
| Conditions | Day · Visual Meteorological Cond |
| Phase / occurrence | Enroute-cruise Electrical system malf/failure |
| Pilot age | 67 |
| Pilot total time | 4,516 hrs · High time |
| Time in type | 36 hrs |
| Fatalities | 1, 1 serious |
Probable cause
NTSB findings
- Aircraft-Aircraft oper/perf/capability-Performance/control parameters-Angle of attack-Capability exceeded - C
- Personnel issues-Task performance-Use of equip/info-Aircraft control-Pilot - C
- Aircraft-Aircraft systems-Electrical power system-AC generation system-Failure - F
- Personnel issues-Psychological-Attention/monitoring-Monitoring equip/instruments-Pilot - F
What happened
During a cross country flight, the pilot diverted to another airport. An airport employee who witnessed the accident reported that the pilot made several attempts to contact the airport over the common traffic advisory frequency; however, the pilot did not respond to replies from airport personnel. The airplane made a low pass heading south over the runway with the landing gear extended. After flying out of view, the airplane returned heading north over the parking ramp, about 50-75 feet above ground level. According to the witness, the pilot made a left turn to land but overflew final approach and was attempting to correct and line up with the runway when the airplane stalled and descended in a nose-low attitude to ground impact. It is likely that the critical angle of attack was exceeded during the turn, which resulted in the stall.
Postaccident examination of the wreckage revealed several indications of an electrical problem: the manual fuel pump handle was extended from its stowed position; the manual landing gear hand crank was engaged; and, although the flap switch was in the extend position, the flaps were not extended. When the airplane's generator was placed on a test stand, it failed to produce power. No other mechanical malfunctions or failures with the airframe or engine were found that would have precluded normal operation.
The generator failure was likely the reason that the pilot diverted from his planned route. After the generator failed, limited electrical power would have remained for a short time via the battery, allowing the pilot to transmit over the radio. However, the radio's volume knob was found in the lowest volume setting, which was likely the reason that the pilot did not hear airport personnel responding to his radio calls. It is likely that the generator failure distracted the pilot and contributed to his failure to maintain airplane control while landing.