NTSB Says Contaminated Wing Caused Fatal Crash In Colorado

Washington, DC - The National Transportation Safety Board today determined that the probable cause of a corporate jet crash in Colorado was the flight crew's failure to ensure that the airplane's wings were free of ice or snow contamination that accumulated while the airplane was on the ground. This failure resulted in an attempted takeoff with upper wing contamination that induced the subsequent stall and collision with the ground.

"It is imperative that flight crews adhere to the ground inspections and deicing guidelines that are in place when freezing precipitation is present while on the ground," said NTSB Acting Chairman Mark Rosenker. "It is paramount that the aircraft is free of contamination before attempting to takeoff during periods of freezing precipitation."

On November 28, 2004, a Canadair, Ltd., CL-600-2A12, registered to Hop-a-Jet, Inc., and operated by Air Castle Corporation dba Global Aviation as Glo-Air flight 73, collided with the ground during takeoff at Montrose Regional Airport, Montrose, Colorado. Instrument meteorological conditions prevailed, and snow was falling. Of the six occupants on board, the captain, the flight attendant, and one passenger were killed, and the first officer and two passengers were seriously injured. Impact forces and postcrash fire destroyed the airplane.

The Board's investigation found that the presence of upper wing contamination is likely because the airplane was parked on the ground for about 40 to 45 minutes during freezing precipitation and it was not deiced. Witness reports state that upper wing surface contamination was evident while the airplane was parked as well as slush sliding from the top of the fuselage before takeoff, which further confirms the presence of contamination.

The investigation confirmed that this type of contamination can easily accumulate while an airplane is parked and exposed to freezing precipitation and it accumulates on upper surface areas that cannot be protected by the wing leading-edge anti-ice system.

Although it is evident that the upper wing surface contamination accumulated while the airplane was on the ground, the Board found that, on the basis of the witness reports, the flight crewmembers would have seen the contamination if they had carefully visually examined the airplane's upper wing surfaces. A tactile examination of the wings is necessary to detect hazardous accumulation of ice that may be visually difficult to detect.

As a result of the information found while conducting the investigation, the Safety Board concluded that the flight crew attempted to take off with upper wing contamination that induced a stall and loss of roll control shortly after lift off. The airplane did not climb but rolled violently left and right several times before it collided with the ground.