NTSB Identification: CHI04LA129.
The docket is stored in the Docket Management System (DMS). Please contact Records Management Division
Accident occurred Monday, May 31, 2004 in Vermontville, MI
Probable Cause Approval Date: 04/28/2005
Aircraft: Hall Lancair IV-P, registration: N707SH
Injuries: 3 Fatal.

NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.

The airplane flew into a thunderstorm during cruise flight and subsequently entered a flat spin until impact with terrain. The airplane had been given a heading to avoid the adverse weather by Lansing approach control. During transfer of control between Lansing approach and Cleveland center, the Cleveland controller was advised that the aircraft had been given a heading to avoid the adverse weather. After the handoff, the Cleveland controller instructed the pilot to proceed direct to an en-route fix when able, but did not provide any information about radar-observed weather ahead of the aircraft. The Chicago center controller who next handled the airplane was briefed that the airplane was proceeding direct to the en-route fix and had not requested any weather deviations. About seven minutes after the handoff between Cleveland and Chicago centers, the pilot transmitted, "Center this is uh 707SH what do you show us in up here?" Aircraft and weather radar data showed the accident airplane flew into an area of level six precipitation (extreme weather) prior to a rapid loss of altitude. Several witnesses reported first hearing the sound of a revving aircraft engine before seeing the airplane descending rapidly in a spiraling descent. A pilot-rated witness reported that the airplane was in a "flat spin" before impacting the terrain. Before the pilot departed on the accident flight, he was given a weather briefing that indicated his route of flight would take him into areas of thunderstorms, moderate turbulence, and icing. According to available pilot flight records, the pilot did not have a current biennial flight review and was not instrument current, as required by federal aviation regulations. No pre-impact anomalies were found with the airplane during the post-accident inspection.


The National Transportation Safety Board determines the probable cause(s) of this accident to be:

The failure of Air Route Traffic Control Center controllers to provide adverse weather avoidance assistance as required by FAA directives, which led to the airplane's encounter with a thunderstorm and subsequent loss of control. Contributing to the accident was the pilot's decision to conduct flight into an area of known thunderstorms.


Full narrative available

Index for May2004 | Index of months