History of Flight
On October 21, 2011, about 0415 Pacific daylight time, N422HP, a Piper PA-46R-350T airplane, sustained substantial damage as a result of a forced landing following a loss of engine power near Paso Robles Municipal Airport (PRB), Paso Robles, California. The pilot, the sole occupant, suffered minor injuries. The airplane is registered to Central Valley Mortgage Services of Porterville, California. The cross-country business flight was operated under 14 CFR Part 91 with an instrument flight rules (IFR) flight plan. The flight departed Porterville Municipal Airport (PTV) about 0300, with PRB as destination.
The pilot reported that after missing the first instrument approach, he was cleared for a second approach. While inbound, the engine made a sound similar to fuel starvation. The pilot set the mixture to full rich and turned on the fuel pump, but no change occurred. He switched fuel tanks with no effect. As altitude was lost rapidly, he prepared for a glassy water-type landing due to fog, dark night, and hilly terrain. The throttle was full forward, but the engine did not produce full power. The airplane impacted an open field in the landing configuration and came to rest upright.
An onsite postaccident examination by an FAA inspector revealed substantial damage to both wings. Both main landing gear and flaps were extended; the nose landing gear was bent aft. The empennage was undamaged. The airplane was recovered for further examination.
Pilot Information
The pilot, age 65, held an airline transport pilot certificate with ratings for airplane single-engine land and sea, multiengine land and sea, and instrument airplane. He also held a flight instructor certificate. He reported 32,476.7 total flight hours, with 23,061.7 in single-engine airplanes and 420 hours in the accident make and model. His most recent flight review was September 21, 2010. A second-class medical certificate was issued on July 29, 2011, with the restriction that glasses must be available for near vision.
Aircraft Information
The 2009 fixed-wing single-engine airplane, serial number 4692122, received its airworthiness certificate on May 29, 2009. It was equipped with a Lycoming TIO-540-AE2A turbocharged, fuel-injected reciprocating engine rated at 350 horsepower, and a three-blade Hartzell constant speed propeller. The most recent annual inspection was on May 4, 2011, at 281.1 total aircraft hours. A left magneto was removed and reinstalled on October 18, 2011, at 336.6 hours.
The airplane had an Avidyne Flightmax Entegra EX5000 R8.1 Multi-function Display (MFD). The most recent fueling was on October 7, 2011, at Visalia Municipal Airport, with 69.4 gallons of 100LL aviation fuel. The only flight during the preceding two weeks was a reposition flight from Visalia to Porterville (about 23 nautical miles).
Meteorological Information
At 0403, PRB weather reported wind 310° at 6 knots, visibility 1¾ miles, mist, overcast clouds at 200 feet msl, temperature 12°C, dew point 11°C, altimeter 30.08 inHg. At 0414, wind 300° at 4 knots, visibility 2½ miles, mist, overcast 200 feet msl, temperature 12°C, dew point 11°C, altimeter 30.09 inHg.
Wreckage and Impact Information
The airplane came to rest upright in an open field with gentle rolling terrain, about 3.07 nm north and slightly west of the extended centerline of runway 19 at PRB. Coordinates: 35°43.862'N, 120°36.905'W; elevation 927 feet msl. Both wings sustained substantial damage; all three propeller blades were damaged; flaps and landing gear were extended. The cabin and aft fuselage, including empennage, were intact and undamaged.
Tests and Research
On November 9–10, 2011, the NTSB, FAA, Lycoming Engines, and Piper Aircraft examined the airplane at Plain Parts in Pleasant Grove, California.
Multi-Function Display (MFD) Examination
The MFD memory card provided GPS data and engine parameters. Data covered 03:15:00 to 04:15:00 PDT, with the last point at 04:14:06. A Lycoming engineer noted that during the missed approach at 04:01, the engine was not at full rich. At 04:06, full power was made (42 inHg MAP, 2500 RPM) but with low fuel flow (0.43 BSFC), causing high turbine inlet temperature (TIT) up to 1768°F and cylinder head temperature (CHT) around 450°F. At 04:06:30, the pilot went to full rich. At 04:09:30, manifold pressure dropped to about 18 inHg, suggesting throttle closure. A Piper engineer stated that the data ends during a second approach attempt; MAP decreased in steps, and at the end, MAP was about 5-6 inHg, indicating throttle closed or nearly closed. No obvious evidence of a powerplant-related failure was found.
Engine Examination
The engine was examined. Fuel injection servo, throttle/mixture controls, and fuel lines were secure. Fuel flow divider and nozzles were intact. Fuel pump was not removed. The fuel selector/gascolator filter screen was clean. An engine operational check showed no anomalies. Spark plugs indicated even fuel distribution. Turbocharger components were undamaged. The crankshaft rotated freely with thumb compression on all cylinders. A test propeller was installed for an engine run. The engine started smoothly, produced normal oil and fuel pressure, and magnetos checked within specifications. Throttle advanced to maximum stop produced manifold pressures within specification.
Fuel Samples
Two fuel samples were tested. Results were within specification except: potential gum (ASTM D873) higher than spec, and vapor pressure (ASTM D5191) lower than spec. These are consistent with aged fuel or fuel exposed to air.
Fuel Servo and Flow Divider Examination
On November 28, 2011, the fuel servo and flow divider were examined at Precision Airmotive. No anomalies were noted that would preclude normal operation.