Piper PA-32-300 N717RL

Before the accident flight, the airplane had sat in its hangar for the previous 2 months with its fuel tanks half full under varying temperature conditions. The pilot had planned on flying to a safety seminar that began at 1630, so he had the airplane pulled out of its hangar, and its main fuel tanks were topped off from a fuel truck. After his arrival at the airport shortly before 1700, the pilot performed a preflight inspection. The manager of the hangar facility described the pilot's preflight inspection as "real quick." A lineman observed the pilot in a position to reach the fuel strainer valve, but he did not see the pilot sumping the main fuel tanks. When the lineman drove by the airplane, he saw a puddle about 1 foot in diameter on the tarmac beneath the fuel strainer, but he did not note anything under either main fuel tank drain. The lineman also noted that the airplane had an underinflated tire, but, due to other duties, he could not warn the pilot before he taxied the airplane away. About 2 minutes after takeoff, the pilot reported an "engine problem" to air traffic control and turned the airplane back toward the airport. The airplane subsequently descended at a steep angle, consistent with a stall, into a house located in a populated area. The airplane impacted the roof, came to rest upside down, and was subsequently mostly consumed in a postcrash fire. Postaccident examination of the airplane revealed evidence indicating that the airplane was not under power at the time of the accident; the fuel-injected engine was charred and the propeller did not exhibit torsional bending or leading edge damage that would have been present if it had been under power. No preexisting mechanical anomalies were found that would have precluded normal engine operation. However, when the fuel flow divider was opened, water was found in it, which likely resulted in the loss of engine power. Water typically enters fuel tanks via three sources: leakage, normally through a fuel cap; contaminated fuel sources; and fuel tank condensation. The fuel cap was likely not the source of water since the airplane was stored in a hangar. Contaminated fuel from the fuel truck was also not the likely source of water since the truck was reportedly sumped daily. Further, on the day of the accident, five airplanes received fuel from the same truck before the accident airplane with no reports of any performance anomalies, and a clean fuel sample was taken from the truck about 20 minutes after the accident. It is more likely that condensation occurred in the half-filled fuel tanks during the previous 2 months that the airplane was sitting in the hangar under varying temperature conditions. Regardless, the pilot had an opportunity to eliminate the condensation during the preflight inspection. However, as noted previously, not enough evidence existed to determine whether the pilot actually drained each main tank to ensure that all of the water was removed. It is likely that the pilot either did not sufficiently drain the main fuel tanks or that he was relying on draining the main fuel tanks through the fuel strainer and fuel lines and did not sufficiently drain them all. Given witness statements indicating that the pilot was in a hurry and his oversight of the underinflated tire, it is likely that the pilot's preflight inspection was inadequate, which resulted in his failure to notice the fuel tank condensation.

Quoted verbatim from the NTSB record.