Accident Overview
On July 25, 2015, at approximately 1630 Pacific daylight time, a Stinson 108-3 airplane, registration N6152M, sustained substantial damage during a forced landing near North Las Vegas Airport (VGT) in Las Vegas, Nevada. The aircraft was operated by the pilot under Part 91 of the Federal Aviation Regulations. The private pilot, who was the sole occupant, was not injured. The flight was a personal cross-country trip destined for Triangle Airpark in White Hills, Arizona, and had just departed VGT at the time of the incident. Visual meteorological conditions prevailed, and no flight plan was filed.
According to the pilot, no anomalies were noted during preflight inspection or engine runup. The tower controller instructed departure from runway 12R with left traffic. After takeoff, the pilot maintained about 80 mph during climb. At approximately 800 feet above ground level, while initiating a left turn, the airplane stopped climbing and began shaking. The pilot lowered the nose, and some power returned. He initially continued the turn to attempt a landing on runway 30R, but when the airplane began to sink, he chose to land straight ahead on a paved parking area. Using a slip maneuver to descend, he touched down about halfway down the tarmac. After deploying flaps and maneuvering to avoid obstacles, the airplane departed the tarmac, struck a fence, and nosed over. The pilot reported no preimpact mechanical malfunctions or anomalies related to the airframe, stating that an additional 50 feet of distance would have allowed him to stop.
An examination by a Federal Aviation Administration inspector revealed substantial damage to the rudder.
Pilot Information
The pilot/owner held a private pilot certificate with a single-engine land rating, issued on July 16, 2014. His most recent FAA third-class medical certificate was issued on September 30, 2010, with no limitations. According to his logbook, he accumulated 98 total flight hours, with 48 hours in the accident aircraft make and model. He had not flown in the three months preceding the accident.
Aircraft Information
The Stinson 108-3 (N6152M) was manufactured in 1948 and registered to Arizona Land Holdings, LLC, on July 16, 2014. The most recent annual inspection was completed on June 12, 2014, at a recorded tachometer time of 2,835.8 hours, though the pilot noted that the mechanic erroneously recorded the time and it should have been 283.58 hours. The tachometer had been replaced about 20 years prior, but no installation record was found. At the accident time, the aircraft had accumulated approximately 44.6 flight hours since the last inspection, and about 2,868 total flight hours.
The aircraft was equipped with a Franklin 6A4-165-B3, 165-horsepower engine. The engine's last annual inspection on June 12, 2014, recorded cylinder compression values between 71 and 74 psi for all six cylinders. The last engine overhaul could not be determined as the engine logbook was not provided.
Engine Examination
On August 26, 2015, an examination of the engine was conducted by a certified mechanic under NTSB and FAA supervision. The right-side engine mount was found fractured. The crankshaft rotated by hand with valve-train continuity and thumb compression observed on all cylinders. The propeller remained attached, with one blade showing leading edge damage and the faceplate bent.
Borescope examination revealed normal operating signatures in all cylinders except the number 1 cylinder, which had heavy carbon deposits and a compression reading of 20/80 psi. A pressure test indicated a leak in the exhaust valve, with air flowing through the exhaust pipe. Further inspection showed degradation on one side of the exhaust valve seal, preventing proper seating.
The top spark plugs showed normal wear, but their gaps measured about 0.032 inches, exceeding the prescribed tolerance of 0.014–0.018 inches. Testing of the magnetos found that the number 6 cylinder top magneto primary lead did not produce spark during propeller rotation or when tested with a high-tension lead tester.
Environmental Conditions
An air traffic controller reported winds from 180 degrees at 5 knots, gusting to 14 knots, a few minutes before departure. According to the National Oceanic and Atmospheric Administration, the density altitude at the accident time was 5,538 feet.
The landing area was a parking tarmac on the east side of the airport, approximately 1,000 feet long by 600 feet wide. An airport perimeter fence bordered the north end. The airplane's landing path included obstacles such as two concrete drums and two light posts about 50 feet from the accident site, and several parked airplanes, one about 60 feet from where the aircraft came to rest. An airport employee observed a significant amount of fuel draining from the aircraft during recovery.