This June 2007 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.
Aircraft: Lancair IV-P.
Location: Parowan, Utah.
Aircraft damage: Substantial.
What reportedly happened: The airplane was cruising at 26,000 feet when the pilot noticed some moisture on the windscreen, then the turboprop engine lost power. The pilot performed an emergency descent and at 12,500 feet attempted an engine restart. The attempt was unsuccessful. The pilot glided to the nearest airport, circled, and performed a power-off landing. The airplane crossed the runway threshold at 120 knots, floated, and touched down more than halfway down the runway. The pilot was not able to bring the airplane to a stop before running out of pavement. The Lancair went off the end of the runway and into a fence. The landing gear collapsed.
FAA inspectors did not find any mechanical abnormality with the engine or fuel system during the post-accident inspection. The Pilot Operating Handbook states that an engine relight was possible below 13,000 feet mean sea level, and below 160 knots of airspeed. The pilot could not recall what his airspeed was when he attempted the engine restart. The airplane was not equipped with any type of engine inlet anti-ice or deicing equipment. The pilot said he had been in and out of moisture while at his 26,000 feet cruising altitude, but there had been no ice buildup on his wings or windscreen. A technical representative for Lancair stated that a 3/4 blockage of the engine cowling induction scoop might be enough to starve the engine of air and induce a flameout.
Probable cause: A loss of engine power due to engine inlet icing.
For more information: NTSB.gov/ntsb/brief2.asp?ev_id=20070607X00691&ntsbno=LAX07LA184&akey=1.