Factual Report: Learjet 35 crashes in forest

 - September 21, 2010, 9:56 AM

Bombardier Learjet 35A, Prospect Heights, Ill., Jan. 5, 2010–The twinjet, owned and operated as a cargo hauler by Waterford, Mich.-based Royal Air Freight, was destroyed when it crashed into a forest preserve approximately two miles short of Chicago Executive Airport, killing the pilot and copilot. The Learjet landed in the Des Plaines River at the conclusion of a short flight from Pontiac-Oakland County Airport. 

According to investigators, the crew was performing a circling approach to Runway 34 when the accident occurred. During the right turn to final, witnesses saw the airplane enter a 90-degree-bank right turn, roll inverted and enter a nose-down descent. VMC prevailed at the time of the accident, with 10 miles visibility and a broken cloud layer at 5,500 feet. The airplane was operating on an IFR flight plan for the Part 91 positioning flight. According to airport authorities, no emergency transmissions were received from the aircraft before the accident. 

The wreckage was removed from the river and transported to a secure facility for examination. The Learjet's cockpit voice recorder was recovered intact, and the tape revealed that the crew was concerned about the weather conditions above Lake Michigan. The pilots reported light to moderate icing while passing through clouds at approximately 3,000 feet on approach. After breaking through the cloud layer, the crew lined up for landing and lowered the gear. After requesting full flaps, the captain noticed a problem with the aircraft's handling and asked the copilot if the autopilot was disengaged and to check for any fuel imbalance. The copilot replied, "Looks good. I don't think that spoileron thing is working for some reason." The CVR transcript ended 10 seconds later. 

Also recovered from the wreckage was the non-volatile memory from the digital electronic engine controls, which revealed no performance faults were recorded. An examination of the right-hand spoiler actuator found the piston jammed in the actuator housing, and the hydraulic fluid in the unit appeared to be darker than that found in the other units. Further examination found two gouges on the inside of the housing corresponding with two dents on the outside.