CHI05FA162

The airplane was destroyed on impact with terrain during a forced landing following an observed in-flight loss of engine power after takeoff. A witness observed the takeoff and stated that the airplane took off from the end of runway 34. About halfway down the runway the airplane emitted a sound like a rapid misfire, a pop, and then no more audible engine sounds. The airplane was about 300 to 400 feet above ground level at that point. He said that the airplane turned right then turned left to a bank where the wing was straight down. The airplane's wings then leveled, the airplane descended, and it impacted terrain. He stated that the time from the sounds to the impact was about two to three seconds. An on-scene examination revealed no airframe pre-impact anomalies. An engine examination revealed a cracked crankshaft propeller flange. The engine without the turbochargers and with the original crankshaft was test run up to 2,100 RPM. A propeller and governor inspection revealed no anomalies. Examination of the turbocharger system's exhaust bypass valve assembly revealed its butterfly valve was stuck (bound) in the extended closed position. The engine's cracked crankshaft was removed and a serviceable crankshaft was installed. The engine was test run again with a serviceable exhaust bypass valve assembly. The engine produced rated power. The original exhaust bypass valve assembly was reinstalled. The exhaust bypass valve assembly's wastegate bound again during an engine run and a loss of engine power was observed. Sectioning of the bypass valve assembly revealed a bent wastegate shaft. The valve assembly lever arm was bent and exhibited pre-impact toolmarks consistent with pliers loosening a bound wastegate shaft. The airplane's pilot operating handbook and Federal Aviation Administration (FAA) approved airplane flight manual (POH), in part, stated, "ENGINE POWER LOSS DURING TAKEOFF If sufficient runway remains for a normal landing, leave gear down and land straight ahead." The engine manufacturer's maintenance and operator's manual stated that the wastegate is required to be checked for operation and condition during 100 hour inspections. The manual did not specify a procedure for maintenance personnel on how to check the wastegate's operation and its acceptable condition. National Transportation Safety Board Recommendation A-94-081, issued to the FAA in 1994, stated, "Require the amendment of pilot operating handbooks and airplane flight manuals applicable to aircraft equipped with engine turbochargers by including in the 'Emergency Procedures' section information regarding turbocharger failure. The information should include procedures to minimize potential hazards relating to fire in flight and/or loss of engine power." The airplane's POH latest revision was dated October 14, 2002 and review of the emergency procedures section showed that the POH did not contain information, procedures, or amplified procedures on turbocharger failures. The airplane accumulated 8.7 hours of operation since the last annual inspection.

History of flight

On July 4, 2005, about 1758 central daylight time, a Piper PA-46-310P, N4386G, piloted by a private pilot, was destroyed on impact with terrain during a forced landing following an observed in-flight loss of engine power after takeoff from runway 34 at the Grand Rapids/Itasca County Airport-Gordon Newstrom Field (GPZ), near Grand Rapids, Minnesota. The personal flight was operating under 14 Code of Federal Regulations Part 91. No flight plan was on file. The pilot sustained fatal injuries. The flight was originating at the time of the accident and its destination was unknown.

A witness located at GPZ observed the takeoff and stated that the airplane took off from the end of runway 34. About halfway down the runway the airplane emitted a sound like a rapid misfire, a pop, and then no more audible engine sounds. The airplane was about 300 - 400 feet above ground level at that point. He said that the airplane turned right then turned left to a bank where the wing was straight down. The airplane's wings then leveled, the airplane descended, and it impacted terrain. He stated that the time from the sounds to the impact was about two to three seconds.

Personnel information

The pilot held a private pilot certificate with airplane single-engine land and instrument airplane ratings. Federal Aviation Administration (FAA) records show that the pilot's last medical examination was completed on June 22, 2005, when he was issued a third-class medical certificate with the limitation that he shall possess glasses that correct for near vision. On the application for that medical certificate, the pilot reported that he had accumulated 2,200 hours of total flight time. He reported that he had accumulated 50 hours of flight time in the six months prior to that medical certificate application.

The pilot obtained flight instruction for the PA-46-310P from Simcom. Their training records showed that the pilot's last endorsement for a flight review was on July 1, 2004.

Aircraft information

N4386G, a 1985 Piper PA-46-310P, Malibu, serial number 46-8508037, was an all-metal airplane with semimonocoque fuselage and empennage construction. The airplane was powered by a six-cylinder, horizontally opposed, turbocharged, air cooled, fuel injected, Teledyne Continental Motors (TCM) TSIO-520-BE(1), serial number 528503, engine. The airplane's propeller was a two-bladed Hartzell BHC-C2YF-1BF model. The airplane was equipped with a pressurized cabin, wing flaps, spoilers, a constant speed propeller, and retractable tricycle landing gear. The airplane had a maximum seating capacity of six occupants, to include two cockpit positions and four cabin positions. The airplane has a certified maximum takeoff weight of 4,100 lbs.

The pilot's operating handbook and FAA approved airplane flight manual (POH), in part, stated:

Turbocharging is accomplished by two Garrett - A.I.D.

turbocompressors, one located on each side of the engine.

Turbochargers extract energy from engine cylinder exhaust

gases and use this energy to compress engine induction air.

This allows the engine to maintain rated power at altitude.

When engine induction air is compressed by the turbocharger,

the air temperature is increased. The elevated air temperature

is reduced by air aftercoolers located on each side of the engine.

This aids in engine cooling and improves engine power and

efficiency.

Each turbocharger extracts exhaust energy from its respective

bank of cylinders to pressurize the induction air. Air flows

through the induction inlet louvers into the induction air box,

where it is filtered and divided for distribution to the left and

right turbo compressors. At the compressor, air pressure and

temperature are increased. Pressure increases air density

making a greater mass of air available to the engine cylinders

on each intake stroke. Air then flows through an aftercooler

where air temperature is reduced, further increasing the density

of air available to each cylinder. Downstream the aftercoolers,

air flow joins at the "Y" junction of intake tubes on the top

front of the engine, then passes the throttle butterfly valve and

is divided to individual intake pipes flowing to each cylinder.

Metered fuel is injected into the cylinder head, upstream of the

intake valve. After the fuel burns in the cylinder, exhaust gases

flow into the exhaust manifold and then to turbocharger turbines

where exhaust energy is extracted to drive the compressor.

Turbo compressed air is throttled across the throttle butterfly

valve as set by the throttle lever. A sloped control system

monitors pressure differential and uses engine oil pressure to

automatically position the waste gate valve. The waste gate

bleeds excess exhaust gas from the exhaust manifold crossover

pipe and out the left exhaust stack, bypassing the turbocharger.

Thus the controller automatically maintains manifold pressure.

The engine is well protected against overboost damage from

excessive manifold pressure. The waste gate controller senses

manifold pressure and will continually adjust turbocharger

output, maintaining the manifold pressure set by the throttle. The

controller automatically protects the engine from overboost

damage by limiting manifold pressure to 38 in. Hg. In the event

of a controller malfunction, there is a pressure relief valve on

the induction manifold which will relieve manifold pressure at

42 in. Hg.

Manifold pressure limits can be exceeded with full throttle

operation during certain off standard ambient conditions and low

engine oil temperature. During such conditions limit manifold

pressure to 38 in. Hg maximum.

Aircraft logbooks show that the last annual inspection was performed on May 6, 2005. The aircraft had accumulated a total time of 1,847.7 hours at the time of that annual inspection.

The airplane's POH, in part, stated:

Engine power loss during takeoff

If sufficient runway remains for a normal landing, leave gear down and

land straight ahead.

If area ahead is rough, or if it is necessary to clear obstructions:

Landing gear selector .............................. UP

Meteorological information

At 1755, the recorded GPZ weather was: Wind 290 degrees at 11 knots gusting to 17 knots; visibility 10 statute miles; sky condition few 8,000 feet; temperature 21 degrees C; dew point 12 degrees C; altimeter 29.94 inches of mercury.

Airport information

The North Central US Region Airport/Facility Directory (A/FD) indicated that the airport elevation at GPZ was 1,355 feet above mean sea level (MSL). GPZ was an uncontrolled airport with two runways, 10/28 and 16/34. The A/FD stated that runway 16/34 was 5,755 feet long and 100 feet wide. That runway's surface was composed of asphalt.

Wreckage and impact information

The airplane fuselage came to rest upright northwest of the departure end of runway 34 at latitude 47 degrees 13.018 minutes North and longitude 93 degrees 30.918 minutes West. A ground scar, about 150 feet long with a 287 degrees magnetic heading, was observed. A radio antenna was found at the start of the scar. The airplane's propeller was detached from the engine propeller flange and was found about 135 feet from the start of the ground scar. The right wing was detached from the fuselage and was found near the end of the ground scar about 150 feet from the start of the scar. The airplane fuselage was about 168 feet from the start of the scar and the fuselage was orientated approximately on a 354-degree magnetic heading.

An on-scene examination was conducted. The propeller blades were marked A and B. The propeller blade marked with a "B" exhibited an s-shaped bend. Both propeller blades exhibited chordwise abrasion. The inboard section of the detached right wi