WPR13FA368

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.

The airplane was a Beech E-35, serial number D-3891. A review of the airplane's logbooks revealed that the airplane had a total airframe time of 6,016.5 hours at the last annual inspection dated June 12, 2013. The tachometer read 1,912.5 at the last inspection. The tachometer read 1,960.48 at the accident scene. The engine was a Continental Motors E-225-8, serial number 30267-D-4-8. Total time recorded on the engine at the last 100-hour inspection was 3,652.5 hours, and time since major overhaul was 1,693.3 hours. Last maintenance entry in the engine logbook was dated June 25, 2013, Engine tach time of 1,915.7, installed fuel pump: Romec RD77Q0, SN 19956. The logbook entry was signed by the accident pilot. The most recent maintenance entry regarding the generator was dated June 9, 1982; the recorded tach time was 847.48. The entry stated the generator was removed, and the bearings and oil seal was replaced. The weight and balance was computed using known data and was found to be within the aircraft operating limitations at the time of the accident. The accident airplane's stall speeds were computed using the calculated weight of 2,262 pounds. The stall speeds of the airplane with the flaps retracted, at a 0-degree bank angle was 54 knots, a 30-degree bank angle was 57 knots, a 45-degree bank angle was 63 knots, and a 60-degree bank angle was 74 knots. Yellowstone Airport is an uncontrolled airport, which operated annually between the months of June 1 through September 30. The Airport/ Facility Directory, Northwest U.S., indicated that Yellowstone Airport had an Automated Weather Observation System (AWOS)-3, which broadcast on frequency 118.100. The Airport/ Facility Directory also indicated that Yellowstone runway 19/1 was 8,400 feet long and 150 feet wide. The runway surface was asphalt. The pilot was attempting to contact personnel at the airport via the airport unicom on frequency 123.0 but was unable to hear the responses from personnel on the ground. The pilot was transmitting on the radio trying to establish communication with the Yellowstone unicom but did not indicate there was anything wrong with the airplane. Post accident examination found the volume knob on the airplane communication radio was in the lowest volume setting. On August 12, 2013, about 1130 mountain daylight time (MDT), a Beech E35, N3226C, impacted terrain while landing at Yellowstone Airport (WYS), West Yellowstone, Montana. The airplane was registered to Avery Enterprises, Inc., and operated under the provisions of 14 Code of Federal Regulations (CFR) Part 91. The commercial pilot was fatally injured, and the one passenger sustained serious injuries; the airplane sustained substantial damage by impact forces. The cross-country business flight departed Rigby, Idaho, sometime after 1000, with a planned destination of Tioga, North Dakota. Visual meteorological conditions prevailed, and no flight plan had been filed. The passenger was hospitalized for an extended periodof time and the family reported he had no recollection of the accident. Witnesses at WYS reported that the accident pilot repeatedly attempted to make radio contact on the airport unicom frequency (123.0), but he did not respond to any of the fix base operator's replies. The accident airplane was observed making a low approach down runway 19 between 100-200 feet above ground level, with the landing gear extended. When the witnesses next observed the airplane, it was on the downwind, about 50-75 feet above the ground. The landing gear was still in the extended position, and the engine sounds were normal. One witness watched the airplane as it turned left onto the base leg. It appeared to him that the airplane had overflown final, and was attempting to correct "when it stalled." The witness then saw the airplane descend in a nose low attitude until it impacted the ground. The Gallatin County Coroner completed an autopsy on August 12, 2013. The FAA Civil Aerospace Medical Institute (CAMI), Oklahoma City, Oklahoma, performed toxicological testing of specimens of the pilot. Analysis of the specimens for the pilot contained no findings for carbon monoxide, volatiles or tested drugs. They did not perform tests for cyanide. A review of Federal Aviation Administration (FAA) airman records revealed that the 67-year-old pilot held a commercial pilot certificate with ratings for airplane single-engine land, and instrument airplane. The pilot held a second-class medical certificate issued on June 6, 2013. It had the limitations that the pilot must wear corrective lenses. An examination of the pilot's logbook indicated he had a total flight time of 4,516.0 hours as of July 31, 2013. He logged 35.9 hours in the last 90 days; all of which were in the accident airplane. He completed a biennial flight review on June 12, 2013. On August 14, 2013, investigators examined the airplane wreckage at Arlin's Aircraft Service, Inc., in Belgrade, Montana. The aircraft battery was disconnected at the accident site. Upon examination, no damage was noted to the battery. The voltage was tested at 12 volts with a 60 percent charge load level. External battery power was applied to the airplane with no indication of any energizing of the airplane's systems. The solenoid was found to have a broken post, which prevented activation. It appeared the broken post may have been a result of impact damage. The solenoid was activated by use of a jumper wire. Once the solenoid was activated the electrical systems inside the airplane become energized. Upon examination of the comm-1 radio, the volume knob was observed turned all the way down. The radio exhibited impact damage and was stuck in transmit mode. The generator (Delco-Remy 50 amp, Model 1101908-50A, SN 4116) was removed from the engine and placed on a test stand. The generator failed to produce power. During the disassembly, it was noted that the rear cap bearing was worn and in pieces. The stator was eroded from contact with thearmature. A review of the engine logbook records indicated that the generator was last serviced 1,113 hours prior to the accident. Investigators examined the wreckage at the accident scene. The first identified point of contact (FIPC) was a ground impact where the airplane came to rest. There was no debris path. The orientation of the fuselage was 172 degrees on a 40-degree up-slope. Flight control continuity was established for all flight control surfaces. The airplane was intact with the main landing gear struts protruding through the top of both wings. Both 20-gallon wing fuel tanks were intact; the right fuel tank was void of any fuel, and the left fuel tank contained 12-15 gallons of aviation fuel. The fuel tank selector valve was selected to the left tank. The auxiliary (wobble) fuel pump handle was noted to be extended from its stowed position. The manual landing gear extension handle boot was removed, and the manual landing gear hand crank was engaged, which is the manual landing gear extension position. The landing gear motor circuit breaker was not pulled out. The flap actuation switch was in the extend selection position, and the flaps were found in the retracted position.