History of Flight
On September 24, 2009, about 2044 eastern daylight time, a Piper PA-32-260 (Cherokee Six), N4864S, was substantially damaged when it impacted terrain following a loss of engine power shortly after takeoff from Oakland/Troy Airport (KVLL), Troy, Michigan. The pilot sustained minor injuries. The flight was operated under 14 CFR Part 91 as a personal flight destined for Hillsdale Municipal Airport, Michigan. Night visual meteorological conditions prevailed; no flight plan was filed.
The pilot reported performing a preflight inspection, noting that both inboard (main) tanks were nearly empty and both outboard (tip) tanks were almost full. He had flown earlier that day and his last landing used fuel from the left tip tank. For the accident flight, he did not reposition the fuel selector, so takeoff was performed using the left tip tank. No anomalies were observed during pre-takeoff engine checks. After configuring for a short-field takeoff with 20 degrees of flaps, the pilot established takeoff power and reconfirmed engine operation. Shortly after liftoff, as the airplane approached the departure end of the runway, the engine experienced a quick loss of power followed by total power loss. The pilot noted the airplane was too low for emergency checklists. Seeing the stall light flicker, he focused on a forced landing in a parking lot north of the departure threshold. During the forced landing, the airplane impacted a shopping cart corral and a tree before sliding down an embankment into another parking lot and grassy area. A postimpact ground fire at the right wingtip was quickly extinguished by first responders.
A witness reported hearing the engine momentarily "stall" after takeoff, then resume briefly before a complete loss of power. Multiple witnesses saw the airplane impact the corral and descend the embankment. The pilot had already extracted himself and did not appear seriously injured.
Wreckage and Examination
After the accident, the pilot and airport manager visually inspected the fuel tanks. Both main tanks were visibly empty. The right tip tank was destroyed by impact and fire, containing no recoverable fuel. The left tip tank appeared "full of fuel" to the pilot. No fuel leakage or spill was observed at the site. The airplane was recovered to a locked hangar at KVLL.
On September 28, 2009, FAA inspectors examined the wreckage. The airplane rested on its fractured right wing and engine, with right main and nose landing gear collapsed. In that attitude, the left tip tank appeared between 1/2 and 3/4 of its 17-gallon capacity. The left main tank had no visible fuel; the right main tank was empty but had a damaged fuel drain port. The cockpit fuel selector was positioned on the left tip tank.
On October 6, 2009, FAA conducted an operational engine test run at NTSB request. The airplane was lifted to a slightly right-wing-down, near-level attitude. No fuel leaks were observed when the system was pressurized using the left tip tank. The engine ran smoothly at various speeds; no anomalies were noted on cockpit gauges. The test lasted about 1 minute 17 seconds per engine monitor data.
On October 26, 2009, NTSB and FAA revisited. The airplane remained in its postaccident attitude. The left tip tank appeared 1/2 to 3/4 full. After leveling, it appeared 1/4 to 1/2 full. No fuel loss occurred between observations. Using the electric fuel pump, investigators drained the left main and left tip tanks. The left main contained about 0.6 gallons; the left tip contained about 4.5 gallons. All fuel was blue, consistent with 100LL, and free of water or contaminants. The right main was reconfirmed empty.
Fuel System Analysis
The left tip tank was removed and the 4.5 gallons returned. The fuel outlet port was near the aft inboard corner. The tank was rotated to simulate aircraft attitudes. With 4.5 gallons, the outlet became uncovered when the tank was rotated 20.5 degrees left from a 7-degree right-wing-down (aligned with wing dihedral). This indicated that a lateral acceleration of about 0.35 Gs at the tank could unport it in a ground turn. Recorded GPS data suggested the airplane turned 90 degrees in about 2 seconds at low speed before takeoff, potentially unporting the tank briefly. After liftoff, high pitch attitude would increase fuel level at the outlet, requiring greater lateral Gs to unport.
Fuel starvation tests on another PA-32-260 showed that with an empty tip tank selected, the engine could run up to 40 seconds at full throttle after switching. The accident flight's GPS data showed power loss occurred 22 to 27 seconds after takeoff roll began.
Placards and Flight Manual
The airplane's placard (part number 69192) stated: "All Weight In Excess of 3112 Pounds Must Be Fuel Weight Only; Fill Tip Tanks First, Use Main Tanks First; Restrict Passenger Weights or Cargo Weight As Required For Compliance." The applicable Owner's Handbook recommended takeoff on the fullest main tank to ensure best fuel flow. It did not address takeoffs from tip tanks when main tanks were empty. The required AFM (Report VB-156, revision 7) contained the same placard language. The pilot had revision 6 in the airplane, but the placard itself was correct.
Postaccident Calculations
Fuel consumption calculations based on pilot logs and engine data showed that since last fueling on September 2, 2009 (46.43 gallons added), the engine had operated about 4.5 hours. Average burn rate was estimated at 11.9 gph, yielding about 54 gallons used. With 84-gallon capacity, up to 30 gallons could remain. However, the pilot reported using both main tanks before selecting the left tip tank. Postaccident, about 22 gallons were accounted for: 4.5 in left tip, 0.6 in left main, empty right main, and an unknown amount in the destroyed right tip (17 gallons or less). The pilot contended the left tip had 1/2 to 3/4 of its 17 gallons before the flight, and that fuel starvation likely resulted from fuel sloshing during rotation and climb.
Propeller and Impact Evidence
Both propeller blades had leading-edge damage and curled tips. Four strike marks in the parking lot were consistent with a rotating propeller; distances between marks ranged from 41 to 72 inches.
Probable Cause
The source does not state a probable cause. The pilot suggested the loss of engine power was likely due to fuel starvation from fuel sloshing in the left tip tank during rotation and initial climb.