National Transportation Safety Board
Office of Public Affairs
On March 23, 1999, an experimental Cirrus SR20 aircraft (N115CD) was destroyed on impact with terrain following a landing attempt at Duluth International Airport in Duluth, Minn. The National Transportation Safety Board continues to investigate the crash, which killed the plane's only occupant. A preliminary factual report is available on the Safety Board's web site, www.ntsb.gov. Although the probable cause of the crash has not been established, the Safety Board is releasing the following factual information developed during the course of its investigation:
Examination of air traffic control communications and radar data reveal that the airplane departed the Duluth International Airport at 1:12 p.m. and climbed to the north. The airplane made several right turns as it climbed to a maximum altitude of 6,500 feet above mean sea level. The airplane then began a descent and a turn to the left about the time that the pilot declared an emergency. Radar data and ground eyewitness statements indicate that the airplane made only turns to the left as it approached the airport. About 2 miles north of the airport, the pilot reported a flight control problem. The airplane subsequently impacted terrain in a nose-down, left-wing low attitude south of the airport after two passes along Runway 27. Gusting winds from the northwest prevailed at the time.
Examination of the wreckage revealed no evidence of a fire or in-flight structural failure. Also, no pre-impact failures or malfunctions with the engine, propeller, or systems were found, except for the flight control system of the roll axis. Examination of the wing and aileron structure revealed scratch and rub marks on the upper surface of the right wing skin near the mating area of the right aileron. Corresponding marks were found on the leading edge of the right aileron. Static testing on other Cirrus SR20 prototypes revealed that it is possible for the leading edge of the right aileron to become jammed against the wing when the aileron is deflected downward and the wing is flexed upward to its maximum design limit. The gap tolerances between the aileron and wing are critical factors in determining the potential for jamming.
Cirrus Design Corp. has informed the Safety Board that it is working with the Federal Aviation Administration to resolve the potential for aileron binding.
The Safety Board continues to investigate what role weather, flight control design and production, FAA certification, manufacturer flight test procedures, aircraft performance, and pilot performance may have played in the crash.
Additional factual material has been placed in the public docket. This factual material may be obtained from the Safety Board's Public Inquiries Branch at 202-314-6551. Please refer to case number CHI99FA112.
Although the final report and probable cause will not be released for at least several months, the Safety Board can issue safety recommendations at any time during the course of an investigation.
NTSB Office of Public Affairs: (202) 314-6100
The National Transportation Safety Board (NTSB) is an independent federal agency charged with determining the probable cause
of transportation accidents, promoting transportation safety, and assisting victims of transportation accidents and their families.