N4380D

HISTORY OF FLIGHTOn October 11, 2023, about 1150 mountain standard time, a Piper PA-46-310P Malibu, N4380D, was substantially damaged when it was involved in an accident near Chandler, Arizona. The air transport pilot and passenger were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.

The purpose of the flight was for the accident airplane to be photographed by another pilot from a different airplane. The pilot stated that he believed there were 35 gallons of fuel onboard the airplane based on the airplane’s flight logs. He was unable to visually verify the actual fluid quantity in the tanks during the preflight because it would be below the filler neck. After a normal run-up, the pilot departed runway 22R. During the initial climb, when the airplane was about 5 miles from the departure end of the runway, at an altitude of about 1,500 ft agl, the engine exhibited a partial loss of power.

The pilot declared an emergency to air traffic control and made 180° turn in an attempt to return back to the airport. The airplane was unable to maintain sufficient altitude and the pilot elected to retract the landing gear in an effort to reduce the drag. The pilot touched down in a dirt area about 500 ft short of the threshold for runway 04R. The airplane came to rest upright and sustained damage to the left aileron. AIRCRAFT INFORMATIONThe last maintenance was reported as being an annual inspection that was completed on February 08, 2023, about 52.1 hours before the accident.

A fuel receipt revealed that the last fueling was the addition of 16.5 gallons on September 19, 2023; it is unknown how much fuel was already in the tanks at that time. Since that fueling, the ADS-B showed that the airplane had flown about 2 hours and 45 minutes over 4 different flights. The FAA reported that the last occasion the fuel tanks were topped off to full was in March 2023. Thereafter, fuel quantities could not be definitely determined, nor could the fuel loss from evaporation be quantified.

According to the airplane’s Pilot’s Operating Handbook (POH):

Fuel is stored in two main integral wing tanks located outboard of the mid-wing splice. Fuel quantity held by each wing tank is 60 usable gallons with one gallon of unusable fuel, for a total of 122 gallons…Fuel quantity is indicated by gauges located above the fuel selector handle. Each tank has two sensor sending units. Gauges are electrical and will operate when the battery switch is ON. Fuel tanks can be visually confirmed full if fuel level is up to the filler neck…Selection of left or right auxiliary fuel pump is determined at the fuel selector by moving the selector handle to the left or right tank

The fuel tanks are independent of each other, and it is not possible to draw fuel from both tanks at the same time. AIRPORT INFORMATIONThe last maintenance was reported as being an annual inspection that was completed on February 08, 2023, about 52.1 hours before the accident.

A fuel receipt revealed that the last fueling was the addition of 16.5 gallons on September 19, 2023; it is unknown how much fuel was already in the tanks at that time. Since that fueling, the ADS-B showed that the airplane had flown about 2 hours and 45 minutes over 4 different flights. The FAA reported that the last occasion the fuel tanks were topped off to full was in March 2023. Thereafter, fuel quantities could not be definitely determined, nor could the fuel loss from evaporation be quantified.

According to the airplane’s Pilot’s Operating Handbook (POH):

Fuel is stored in two main integral wing tanks located outboard of the mid-wing splice. Fuel quantity held by each wing tank is 60 usable gallons with one gallon of unusable fuel, for a total of 122 gallons…Fuel quantity is indicated by gauges located above the fuel selector handle. Each tank has two sensor sending units. Gauges are electrical and will operate when the battery switch is ON. Fuel tanks can be visually confirmed full if fuel level is up to the filler neck…Selection of left or right auxiliary fuel pump is determined at the fuel selector by moving the selector handle to the left or right tank

The fuel tanks are independent of each other, and it is not possible to draw fuel from both tanks at the same time. TESTS AND RESEARCHThe FAA inspector who responded to the accident stated that upon arrival, he drained about 0.5 gallon from each wing tank. After turning the airplane's power on, he noted that the fuel gauges indicated that the fuel tanks were empty and the JPI engine monitor indicated that 32 gallons remained. Neither wings nor their respective fuel tanks were breached; there was no evidence of a fuel leak or blue staining on the airframe. The fuel selector was positioned on the “LEFT” tank.

A postaccident examination was conducted by a certified airframe and powerplant mechanic under the auspices of the FAA inspector. The fuel supply line was disconnected from the firewall supply line (that led to the engine-driven fuel pump). No residual fuel was observed in the line upon disconnection. A flexible extension hose was connected to the firewall line, which remained attached to the engine-driven fuel pump. The opposite end of the hose was placed into a five-gallon container.

With the airplane’s battery master switch powered on, the fuel quantity gauge indicated there was no fuel. Functional testing of the electric boost pumps confirmed operation on both high and low settings, with audible pump activity. Despite sounding as though they were functioning, no fuel exited from the tanks (even during manipulation of the fuel selector to different positions). A visual inspection confirmed that no circuit breakers were pulled or tripped.

The sump drains were removed from both the left and right collector tanks. Approximately six ounces of fuel exited as the drain fittings were being disconnected. There was no other fluid found in the system.

The airplane was equipped with a JPI EDM-900 Primary Engine Data Management System. The system includes several non-primary fuel functions that require manual input by the pilot, including "Fuel Remaining," "Fuel Required," and "Fuel Reserve." The displayed indication of 32 gallons remaining was based on pilot-entered values and was not consistent with the aircraft’s fuel quantity gauges, which indicated that no fuel was onboard.

A review of the non-volatile memory downloaded from the JPI revealed that the engine powered up to takeoff rpm at 1043:11. After 2 minutes of stable power indications, the manifold pressure began to fluctuate in conjunction with changes in exhaust gas temperatures (EGTs). The manifold pressure decreased to atmospheric pressure or below, then increased, as did the EGTs, until approximately 10:45:41. Thereafter, minor fluctuations were observed; however, engine power was not restored.

Fuel flow data from the transducer indicated residual flow around 2 to 3 gallons per hour, consistent with air and fuel droplets moving through the engine-driven and electric boost pumps, a pattern that is consistent with fuel starvation.