History of Flight
The flight departed Renton Municipal Airport at 1431 Pacific standard time on a local, visual flight rules (VFR) flight with a private pilot and one passenger. According to the surviving passenger, during engine start, the engine did not start immediately and turned over several times before starting, which was unusual compared to previous flights. About 30 minutes after takeoff, the engine began to sputter and then stopped completely. The passenger reported that the pilot attempted to restart the engine without success, and the airplane began losing altitude. The passenger observed the stall warning light illuminate while the airplane was in a turn. Several witnesses in the residential area reported hearing a pop or sputter followed by silence, and seeing the propeller stop before a thud. One witness observed the airplane in a hard bank and descending. Data from the pilot's handheld GPS device showed the airplane departed and flew northwest, then southeast, north, and northwest over about 18 minutes at altitudes between 1,500 and 1,700 feet mean sea level (msl) and groundspeeds around 107 knots. At about 1449, the airplane turned southwest toward the departure airport. At 1451:36, groundspeed decreased from 91 to 69 knots within 5 seconds, and the airplane began a slow descending right turn. The track showed a left turn at low altitude, with groundspeed dropping from 57 to 40 knots in the final seconds. The last recorded data at 1452:47 showed an altitude of 569 feet above ground level (agl) on a heading of 202 degrees.
Wreckage and Impact Information
The main wreckage came to rest partially inside a garage of a residence, with the engine and cockpit inside. The left wing initially struck a parked van, separating from the fuselage and coming to rest about 20 feet west. The aft fuselage remained intact and oriented upward at about 30 degrees. The forward cabin sustained extensive impact damage. The right wing remained attached and was angled upward. All flight control cables remained attached and continuity was confirmed from control surfaces to cockpit. The elevator trim tab was deflected full right. The tail wheel assembly was undamaged.
Personnel Information
The 45-year-old pilot held a private pilot certificate with single-engine land and instrument ratings and a third-class medical certificate issued September 2012. His logbook, last updated November 27, 2012, showed 946.3 total flight hours, including 897.3 as pilot-in-command, 110.7 hours in the accident make/model, and 668 hours of tailwheel time. His most recent flight review was completed September 7, 2012. The pilot had not flown the accident airplane since November 27, 2012, a period of 102 days. The airplane was not stored in a hangar and remained tied down outdoors at Renton Municipal Airport. No fueling records showed any refueling after the November flight.
Aircraft Information
The 1975 Maule M-5-210C is a single-engine, high-wing airplane equipped with a Teledyne Continental IO-360-D fuel-injected engine and a McCauley constant-speed propeller. The most recent annual inspection was performed July 26, 2011, at an engine total time of 1,802.2 hours, with 153.0 hours since major overhaul. At the accident, the tachometer read 3,143.7 hours.
Meteorological Information
Weather observations near the accident site at 1453 showed wind from 170 degrees at 5 knots at Renton (16 nm south-southwest) and wind from 290 degrees at 5 knots at Paine Field (14 nm northwest). Visibility was 10 miles, skies were clear. Temperature was 13°C at Renton and 9°C at Paine Field. Total monthly rainfall from November 2012 to March 2013 ranged from 1.58 to 8.28 inches.
Medical and Pathological Information
An autopsy attributed the pilot's cause of death to blunt force injuries. Forensic toxicology testing detected no ethanol, carbon monoxide, or drugs in the specimens. Cyanide tests were not performed.
Tests and Research
The engine was examined and showed no evidence of catastrophic failure. Crankshaft and camshaft continuity were confirmed through thumb compression in all cylinders. The mixture control lever was found in the idle-cutoff position. The throttle valve was in the full open position. The fuel system contained a small amount of beige sludge in the manifold valve plunger and a drop of beige water. Fuel recovered from the right wing tanks (about 5 gallons) was analyzed and found to be out of specification for potential gum, Reid vapor pressure, and distillation temperature, consistent with aged or exposed fuel. The fuel sample contained 113 mg/kg of absorbed water, which can separate under temperature changes and cause icing. The GPS device was downloaded and showed the final data point at 1452:47 PST at 650 feet GPS altitude, with average groundspeed of 40 knots between the last two track points.