Oakland/Troy Airport
Aircraft Accident/Incident Report

Troy, Michigan 48084
Thursday, September 24, 2009 20:44 EDT

The pilot reported that, during his preflight inspection, he verified the fuel quantity and its distribution in the airplane's four fuel tanks. He noted that both inboard (main) fuel tanks were essentially empty and that both outboard (tip) tanks were almost full. He stated that he performed the accident takeoff using fuel from the left tip tank. Before takeoff, he verified that no anomalies existed with the engine operation during the engine check and when he applied power for takeoff. The pilot performed a short-field takeoff with 20 degrees of flaps. The pilot stated that, as the airplane approached the departure end of the runway, the engine experienced a "quick loss of power," which was shortly followed by a sustained loss of power. The pilot immediately performed a forced landing in a parking lot just north of the departure threshold. During the forced landing, the airplane impacted a shopping cart corral and a tree and then slid down an embankment. The right wing tip and tank were sheared off during impact, and a postimpact ground fire ensued at the sheared right wing tip. Postaccident examination of the airplane revealed that the left tip tank contained 4.5 gallons of fuel, about 1/4 of its 17-gallon capacity. (The pilot stated in a postaccident interview that the left tip tank contained 1/2 to 3/4 of its total capacity.) The left main tank contained about 0.6 gallons of fuel. The right main tank did not contain any fuel; however, the fuel drain for that tank was separated from the tank during impact. No fuel was observed leaking from the right main tank, nor was there an odor of leaking fuel. The right tip tank was destroyed by impact damage and the subsequent fire. The cockpit fuel selector was found positioned on the left tip tank. During a postaccident interview with a Federal Aviation Administration inspector, the pilot stated that, after the loss of engine power, he reached for the fuel selector but was unsure of what he did because his attention was diverted by the stall warning light. An operational engine test run revealed no anomalies. The pilot stated that he believed the loss of engine power during initial climb was likely due to fuel starvation, as a result of fuel sloshing in the left tip tank during rotation and initial climb. However, calculations, testing, and operational history showed that the left tip tank would not unport and experience fuel starvation leading to loss of engine power if it contained 4.5 gallons of fuel unless maneuvering during a turning takeoff was extreme. The accident airplane did not experience extreme maneuvers during or immediately after takeoff. Global positioning system (GPS) data downloaded from the pilot's handheld receiver showed that ground maneuvering for the accident takeoff was routine and did not achieve the lateral accelerations necessary to disrupt fuel flow from the left tip tank. Thus, a takeoff using the left tip tank containing 4.5 gallons of fuel would not result in fuel starvation and, ultimately, loss of engine power. Additional testing showed that if a fuel tank was depleted of its useable fuel, the engine would continue to run at takeoff power for an additional 35 to 40 seconds. GPS data for the accident flight showed that the loss of engine power likely occurred 22 to 27 seconds after the takeoff roll was initiated. A takeoff on an empty or nearly empty main tank could result in fuel starvation. The accident takeoff was likely performed on an empty or nearly empty main tank.

A loss of engine power during initial climb due to fuel starvation as a result of the pilot's selection of an empty or nearly empty main tank for takeoff.