N37SV

HISTORY OF FLIGHT

On October 12, 2011, about 1334 eastern daylight time, a Socata TBM 700, N37SV, registered to SV Leasing Company of Florida, operated by SOCATA North America, Inc., sustained substantial damage during a forced landing on a highway near Hollywood, Florida, following total loss of engine power. Visual meteorological conditions prevailed at the time and an instrument flight rules (IFR) flight plan was filed for the 14 Code of Federal Regulations (CFR) Part 91 maintenance test flight from North Perry Airport (HWO), Hollywood, Florida. The airline transport pilot and pilot-rated other crewmember sustained minor injuries; there were no ground injuries. The flight originated from HWO about 1216.

The purpose of the flight was a maintenance test flight following a 600 hour and annual inspection.

According to the right front seat occupant, in anticipation of the flight, he checked the fuel load by applying electrical power and noted the G1000 indicated the left fuel tank had approximately 36 gallons while the right fuel tank had approximately 108 gallons. In an effort to balance the fuel load with the indication of the right fuel tank, he added 72.4 gallons of fuel to the left fuel tank. At the start of the data recorded by the G1000 for the accident flight, the recorded capacity in the left fuel tank was approximately 105 gallons while the amount in the right fuel tank was approximately 108 gallons.

The PIC reported that because of the fuel load on-board, he could not see the level of fuel in the tanks; therefore, he did not visually check the fuel tanks. By cockpit indication, the left tank had approximately 105 gallons and the right tank had approximately 108 gallons. The flight departed HWO, but he could not recall the fuel selector position beneath the thrust lever quadrant. He further stated that the fuel selector switch on the overhead panel was in the "auto" position.

After takeoff, the flight climbed to flight level (FL) 280, and levelled off at that altitude about 20 minutes after takeoff. While at that altitude they received a "Fuel Low R" amber warning CAS message on the G1000. He checked the right fuel gauge which indicated 98 gallons, and confirmed that the fuel selector automatically switched to the left tank. After about 10 seconds the amber warning CAS message went out. He attributed the annunciation to be associated with a failure or malfunction of the sensor, and told the mechanic to write this issue down so it could be replaced after the flight. The flight continued and they received an amber warning CAS message, "Fuel Unbalance" which the right fuel tank had more fuel so he switched the fuel selector to supply fuel from the right tank to the engine. The G1000 indicates they remained at that altitude for approximately 8 minutes.

He then initiated a quick descent to 10,000 feet mean sea level (msl) and during the descent accelerated to Vmo to test the aural warning horn. They descended to and maintained 10,000 feet msl for about 15 minutes and at an unknown time, they received an amber warning CAS message "Fuel Low R." Once again he checked the right fuel gauge which indicated it had 92 gallons and confirmed that the fuel tank selector automatically switched to the left tank. After about 10 seconds the CAS message went out. Either just before or during descent to 4,000 feet, they received an amber CAS message "Fuel Unbalance." Because the right fuel gauge indicated the fullest tank was the right tank, he switched the fuel selector to supply fuel to the engine from the right tank.

The flight proceeded to the Opa-Locka Executive Airport, where he executed an ILS approach which terminated with a low approach. The pilot cancelled the IFR clearance and proceeded VFR towards HWO. While in contact with the HWO air traffic control tower, the flight was cleared to join the left downwind for runway 27L. Upon entering the downwind leg they received another amber CAS message "Fuel Unbalance" and at this time the left fuel gauge indicated 55 gallons while the right fuel gauge indicated 74 gallons. Because he intended on landing within a few minutes, he put the fuel selector to the manual position and switched to the fullest (right) tank.

Established on final approach to runway 27L at HWO with the gear down, flaps set to landing, and minimum speed requested by air traffic for separation (85 knots indicated airspeed). When the flight was at 800 feet, the red warning CAS message "Fuel Press" illuminated and the right seat occupant with his permission moved the auxiliary fuel boost pump switch from "Auto" to "On" while he, PIC manually moved the fuel selector to the left tank. In an effort to restore engine power he pushed the power lever and used the manual over-ride but with no change. Assured that the engine had quit, he put the condition lever to cutoff, the starter switch on, and then the condition lever to "Hi-Idle" attempting to perform an airstart. At 1332:42, a flightcrew member of the airplane advised the HWO ATCT, "…just lost the engine"; however, the controller did not reply.

The PIC stated that he looked to his left and noticed a clear area on part of the turnpike, so he banked left, and in anticipation of the forced landing, placed the power lever to idle, the condition lever to cutoff, the fuel tank selector to off, and put the electrical gang bar down to secure the airplane's electrical system. He elected to retract the landing gear in an effort to shorten the landing distance. The right front seat occupant reported that the airplane was landed in a southerly direction in the northbound lanes of the Florida Turnpike. There were no ground injuries.

AIRCRAFT INFORMATION

The airplane was manufactured in 2008, by EADS Socata as model TBM 700, and was designated serial number 441. At the time of the accident, it was powered by a 850 horsepower Pratt & Whitney Canada PT6A-66D engine and equipped with a Hartzell HC-E4N-3/E9083 propeller with reverse capability.

The airplane's fuel system consists of a 150.5 gallon capacity wet wing fuel tank in each wing, with a resulting total usable capacity of 292 gallons. Fuel gauging is a capacitance type with 3 probes installed in each wing, and a low fuel sensor installed in each wing inboard of the inboard fuel probe, which provides a low level CAS messages when the fuel quantity remaining in the concerned tank is under about 9 U.S. gallons. The fuel probes are capacitors connected in parallel via electrical harness to the fuel amplifier (FCU) which in turn is connected electrically to the G1000 in the cockpit for display for the fuel tank readings.

Review of the maintenance records revealed an entry on August 4, 2010, indicating, "Troubleshoot right fuel quantity, found pin B at P61 connector loose, removed and replaced pin B at P61 connected as required, performed an operational check of right fuel quantity, system operates normal." The airplane total time at that time was recorded to be 451.1 hours. There was no other record of repair of the right fuel harness.

On September 29, 2011, the airplane was flown to HWO for compliance with an annual/600-Hour inspection. A pre-inspection engine run-up was performed and according to a fuel timeline provided by the maintenance facility, the reading for the fuel level in the right fuel tank at the completion of the run was recorded by the G1000 to be 41 gallons. On October 4, 2011, due to fuel leaking from 2 panels of the right wing, it was drained of fuel. A total of about 70 gallons of fuel were drained from the right fuel tank. The same day, electrical power was applied for about 43 seconds and during this time the right fuel quantity at the beginning and ending of the power-up was recorded to be approximately 11 gallons, though there was no remaining fuel in the fuel tank. The leaking panels were removed, repaired, and reinstalled. On October 5th, the fuel drained from the right tank were placed back into the right wing, and a post maintenance run-up was performed using only fuel from the right fuel tank. This was done in an effort to balance the fuel load. The G1000 recorded that at the completion of the engine run, the right fuel tank contained 51 gallons. The G1000 indicated power application 2 days later indicating the right fuel tank had approximately 143 gallons, despite the fact that it had not been fueled. Five days later, on October 12, 2011, the G1000 indicated power application for less than 30 seconds which indicated the right fuel tank had 107 gallons of fuel, while the left fuel tank had 35.5 gallons of fuel. No maintenance was done to evaluate the reason for the changing right fuel quantity.

Further review of the maintenance records revealed that the airplane was last inspected in accordance with a 600 hour inspection and annual inspection which was signed off as being completed the day before. The airplane total time at that time was recorded to be 593.4, while the airplane total time at the time of the accident was 595.2 hours.

FLIGHT RECORDERS

The airplane was equipped with a Garmin G1000 Integrated Flight Deck, which is a collection of multiple avionics units which include flight displays. Each display has two SD card slots. The SD memory card was removed from the MFD and sent to the NTSB Vehicle Recorder Division for readout.

According to the NTSB Factual Report, the data was extracted normally and contained 59 log files. The event flight was recorded and contained approximately 1 hour and 38 minutes of data; the calculated sample time interval was 1.055 seconds per data record. A review of the recorded data with respect to the fuel level revealed that beginning about 1218, or about 2 minutes after takeoff until 1229, during which time the airplane was at FL190 and climbing to FL280, the fuel level indication for the left steadily decreased consistent with supplying fuel to the engine, while the fuel level indication for right varied with increases noted. The left fu...