Aviation Accident Summaries

Aviation Accident Summary SEA97LA165

MILFORD, UT, USA

Aircraft #1

N6626W

YOUNG TURBO CRUISER

Analysis

The pilot reported that while cruising about 13,500 feet mean seal level over the Rocky Mountains, the engine abruptly stopped. The pilot switched fuel tanks and achieved a restart and then continued to his destination. Approaching the destination, the aircraft developed a moderate vibration which subsided with the reduction and re-application of throttle. The pilot executed a normal approach but was high and initiated a go-around. During the left crosswind turn, the engine abruptly quit for a second time, and the pilot executed a forced landing. During the landing roll, the aircraft's main landing gear folded and collapsed. Post-accident examination of the aircraft revealed 3.5 gallons of fuel remaining in the left wing and 1.5 gallons of fuel remaining in the right wing. The pilot stated that he had departed with full fuel tanks on this flight, which was his first long-distance flight in the experimental airplane. The aircraft's records indicated that its fuel capacity was 60 gallons, of which 56 gallons were considered usable fuel; however the actual fuel capacity and unusable fuel were not verified after the accident. The pilot stated that the aircraft did not have a flight manual, so he based his estimates of 10 gallons per hour fuel burn rate and 130 knots cruise speed at high altitude as a conservative interpretation of the information that had been given to him by the airplane's previous owner (8 to 9 gallons per hour, and 140 knots cruise speed). The pilot flight-planned for an estimated flight time of three hours, and estimated that he would have consumed about half of the fuel carried in the airplane. While en route, he determined that his true airspeed and ground speed were about 103 knots; less than what he had been told by the airplane's previous owner. Actual total flight time for the flight was four hours. No evidence of preexisting mechanical anomalies was found during the post-accident inspection of the damaged airplane.

Factual Information

On July 9, 1997, approximately 0945 mountain daylight time, an experimental Young Turbo Cruiser, N6626W, recently purchased and being flown by a private pilot, was substantially damaged during a forced landing following a total power loss approximately one mile southwest of the Milford airport, Milford, Utah. The pilot was uninjured. Visual meteorological conditions existed and a VFR flight plan had been filed. The flight, which was personal, was to have been operated under 14CFR91, and originated from Boulder, Colorado, approximately four hours earlier. The pilot reported that while en route to Milford, and approximately 13,500 feet MSL over the Rocky Mountains, the engine abruptly stopped. The pilot switched fuel tanks and achieved a restart and then continued to his destination. Approaching Milford the aircraft developed a moderate vibration which subsided with the reduction and re-application of throttle. The pilot executed a normal approach but was high and initiated a go-around. During the left crosswind turn, the engine abruptly quit for a second time, and the pilot executed a forced landing. During the landing roll, the aircraft's main landing gear folded and collapsed. The pilot reported that the aircraft was a modified Piper PA-22 with a Lycoming O-320 engine equipped with a turbo-charger. The pilot stated that the aircraft had a history of the fuel tanks experiencing vacuum problems during flight. The pilot stated that the vents were installed pointing to the rear of the aircraft and that appeared incorrect to him. He was unable to contact the builder to determine the correct installation before he departed for Milford. The pilot reported that at Corona Pass the engine "stopped suddenly" but kept windmilling. After changing the fuel tank selector from the right to the left tank, the engine restarted. The pilot stated that after recovering from his first engine failure he "spent a little extra time" in the vicinity of Granby Airport to regain his comfort level. The pilot further stated, "By this time I concluded that I was going to be about an hour late on my flight plan." Attempts to reach Denver Flight Service to notify them of a delay in his arrival time were unsuccessful. The rest of the flight was uneventful until the approach into Milford. The pilot stated, "Since I was late on my flight plan, I chose to do a full power descent... I remember my indicated airspeed reading about 135 MPH, but there was no mention of the Vne in the logbooks, so I assumed that the speed was reasonable. The airframe began to vibrate very loudly and I thought the propeller was going to come apart... I touched down at the half-way point of the runway and bounced three times and then decided to go around. After the start of the turn to crosswind the engine quit." The pilot then executed an emergency landing off-field. The FAA representative on-site stated that there were 3.5 gallons of fuel remaining in the left wing and 1.5 gallons of fuel remaining in the right wing at the time of the post-crash inspection. The pilot stated that he had departed with full fuel tanks on this flight, which was his first long-distance flight in the experimental airplane. The aircraft's records indicated that its fuel capacity was 60 gallons, of which 56 gallons were considered usable fuel; however the actual fuel capacity and unusable fuel were not verified after the accident. The pilot stated that the aircraft did not have a flight manual, so he based his estimates of 10 gallons per hour fuel burn rate and 130 knots cruise speed at high altitude as a conservative interpretation of the information that had been given to him by the airplane's previous owner (8 to 9 gallons per hour, and 140 knots cruise speed). The direct line mileage between Boulder, Colorado, and Milford, Utah, (due southwest) is approximately 370 nautical miles. The pilot stated that he crossed the Rocky Mountains at Corona Pass, which is approximately 60 miles due south of Boulder and not along the direct flight path, increasing the mileage for the proposed route of flight. The pilot flight-planned for an estimated flight time of three hours, and estimated that he would have consumed about half of the fuel carried in the airplane. While en route, he determined that his true airspeed and ground speed were about 103 knots; less than what he had been told by the airplane's previous owner. Actual total flight time for the flight was four hours. No evidence of preexisting mechanical anomalies was found during the post-accident inspection of the damaged airplane.

Probable Cause and Findings

Loss of engine power due to fuel starvation. Factors include the pilot's fuel consumption calculations based upon insufficient or erroneous information provided by the amateur-built airplane's builder and previous owner, and terrain conditions not suitable for a successful forced landing.

 

Source: NTSB Aviation Accident Database

Get all the details on your iPhone or iPad with:

Aviation Accidents App

In-Depth Access to Aviation Accident Reports