NTSB Factual Report

On November 6, 2010, at 1230 Pacific daylight time, an experimental light sport airplane Lansdorf Qualt 200, N3215S, experienced a partial loss of engine power shortly after takeoff from Sonoma Skypark Airport (0Q9), Sonoma, California. The certificated sport pilot/owner received minor injuries and the passenger received serious injuries. The airplane sustained substantial damage. The pilot operated the airplane under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed for the flight, and no flight plan had been filed. The flight was destined for Petaluma Municipal Airport (O69), Petaluma, California.

In the pilot's written statement to the National Transportation Safety Board (NTSB), he reported that after takeoff from runway 26, it felt as if the airplane were in a strong downdraft or strong tail wind gust, and that "somehow there was not enough power.” He reported that the climb was not regular. When the airplane reached about 100 to 150 feet above ground level (agl), it veered right and rapidly descended to the ground. The airplane subsequently collided with a warehouse about one block from the airport. The empennage and the left elevator separated from the airframe and both wings were crushed and broken.

According to a responding deputy from the Sonoma County Sheriff's Department, a witness reported hearing the engine running, but that it was only producing partial power.

Reported METAR (aviation routine weather report) for 0Q9 at 1154, indicated that winds were from 250 degrees at 4 knots; visibility 10 statute miles; overcast sky conditions at 1,300 feet; temperature 15 degrees Celsius (C ); dew point 11 degrees C; altimeter setting 29.99 inches of Mercury.

An examination of the airframe and engine by the NTSB investigator-in-charge and a representative from Rotech Flight Safety revealed no pre impact anomalies or failures. All of the propeller blades separated close to the blade hub and were torn and broken. During the engine test run, the engine started without hesitation and ran smoothly. An examination of the remaining airframe and related systems revealed no anomalies.

A review of the carburetor icing probability chart, located in the FAA's Special Airworthiness Information Bulletin CE-09-35, dated June 30, 2009, revealed that the airplane was operating in an area favorable for the formation of serious carburetor icing at cruise power.

NTSB Probable Cause

A partial loss of engine power for reasons that could not be determined because postaccident examination of the airframe and engine did not reveal any anomalies that would have precluded normal operation.