Maintenance Flight Goes Bad, 2 Injuries Result

You know that nagging feeling that comes every now and then tells you that something bad is about to happen? If you read through the details of a prelim leading up to a fuel exhaustion accident that took down a TBM 700 (thankfully with only two minor injuries), you have to wonder how many times that feeling cropped up during a brief maintenance flight that went way wrong... If in doubt, figure it out... on the ground.

TBM 700 File Photo

NTSB Identification: ERA12FA023
14 CFR Part 91: General Aviation
Accident occurred Wednesday, October 12, 2011 in Hollywood, FL
Aircraft: SOCATA TBM 700, registration: N37SV
Injuries: 2 Minor.

This is preliminary information, subject to change, and may contain errors. Any errors in this report will be corrected when the final report has been completed.

On October 12, 2011, about 1334 eastern daylight time, a Socata TBM 700, N37SV, registered to and operated by SV Leasing Company of Florida, sustained substantial damage during a forced on a highway near Hollywood, Florida, following total loss of engine power. Visual meteorological conditions prevailed at the time and no 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 certificated 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 inspection. A mechanic involved with a post maintenance engine run reported that after the conclusion of the engine run, the right fuel tank reading was 51 gallons. No fuel was added to the airplane until the day of the accident.

According to the right seat occupant, prior to the flight he applied the aircraft’s battery power and noted the right fuel quantity was 108 gallons, and the left fuel quantity was 36 gallons. He added 72 gallons of fuel to the left fuel tank but did not add any fuel to the right fuel tank.

The PIC reported that because of the fuel load on-board, he did not visually check the fuel tanks because he would be unable see the fuel level. By cockpit indication, the left tank had approximately 104 gallons and the right tank had approximately 105 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, which took approximately 15 minutes. After leveling off at that altitude they received a low fuel warning for the right fuel tank. The warning lasted approximately 10 seconds then went out. He confirmed that the fuel selector automatically shifted to the left tank. He also reported performing a hands off flight control stability test; no discrepancies were noted and the airplane was flying straight and level.

At the end of the cruise portion at FL280, they had a fuel imbalance indication indicating the right side had a greater quantity of fuel that the left fuel tank. He shifted to supply fuel from the left fuel tank. He then initiated a quick descent to FL100 and during the descent accelerated to Vmo to test the aural warning horn. After leveling off at FL100, they had a low fuel warning annunciation from the right fuel tank which lasted approximately 10 seconds and then went out. He confirmed that the fuel selector automatically switched to the left tank and continued the flight. A short time later while flying at FL100, he received another fuel imbalance with the right fuel tank indicating a greater amount. He shifted to supply fuel from the left fuel tank.

When asked to clarify the time between fuel imbalance annunciations he estimated there was maybe 20 minutes. He also said that having an imbalance annunciation is not abnormal.

The flight proceeded to the Opa Locka Airport, where he executed an ILS approach which terminated with a low approach. The airplane then proceeded to HWO, and while on the downwind leg for runway 27L, he had the 3rd fuel imbalance annunciation. He believed the left fuel quantity was 60 gallons and the right was 75 gallons. Because he knew he was close to land, he moved the fuel selector switch on the overhead panel to the manual position, and then switched the fuel selector below the thrust quadrant from the left to right tank position. The flight turned base and final, and while on final approach, for runway 27L, air traffic control (ATC) asked him to maintain minimum speed for spacing. He slowed to 85 knots, extended flaps to the landing position, and lowered the landing gear.

While on final approach for runway 27L, the red “Fuel Press” warning light illuminated and the engine lost power. He told the right seat occupant to reposition the auxiliary fuel pump from the auto to the on position, and at the same time moved the fuel selector below the trust lever quadrant to the left tank position. He verified power loss by advancing the thrust lever forward, but there was no engine response.

He attempted an airstart, and moved the manual override lever to on, then moved the condition lever to the cutoff position. He verified that he had total loss of engine power, placed the starter switch to the on position, and though he did not check the Ng, moved the condition lever to the lo/idle position and high idle. He felt a sensation that the engine was starting, but did not accelerate in 2 seconds. Because the flight was low (100 to 150 feet) above ground level, he saw a highway, but with traffic on the highway elected to retract the landing gear.

The co-pilot reported that the airplane was landed in a southerly direction in the northbound lanes of the Florida Turnpike.

The PIC stated that he stalled the airplane before touchdown to avoid cars ahead. After impact, he turned off the fuel selector and pulled down the crash bar which turned off the airplane’s electrical system.

FMI: www.ntsb.gov