CHI93IA280

The commuter airline turbojet was climbing to its assigned altitude when the captain turned the airplane to avoid a thunderstorm. During the turn the airplane was struck by lightening several times and the right engine ceased operating. The engine was restarted as the airplane descended through 15,000 feet. The airplane continued to its destination after the engine was restarted. An on-scene investigation revealed the airplane had numerous burn spots on its fuselage, wing, right engine, elevator, and right engine.

On July 24, 1993, at 0840 central daylight time (CDT), a Canadair CL 600-2B19, N915CA, operated by Comair Airlines of Cincinnati, Ohio, as flight number 3707, and piloted by airline transport rated pilots, experienced a right engine failure after being struck by lightning during a climb to its assigned altitude. The 14 CFR Part 135 passenger revenue flight was operating on an IFR flight plan in instrument meteorological conditions. The airplane sustained minor damage. The two pilots, flight attendant, and eighteen passengers reported no injuries. The flight departed from Chicago, Illinois, at 0730 CDT.

The captain's NTSB Form 6120.1/2's written statement reveals the airplane was "... flying through intermittent, moderate precipitation, and moderate turbulence... ." The captain stated, "We just started a deviation to the east, left of course, to avoid a level one cell (thunderstorm)... ." After being struck by lightning several times the pilot declared an emergency at 27,000 feet when the right engine ceased operating. Shortly after descending through 15,000 feet the engine was restarted during a second attempt. The pilot requested, and was granted, a clearance to the flight's original destination.

The company's Chief Inspector of Maintenance stated N915CA had many burn marks on its fuselage, wing, right engine, and elevator. The company's chief pilot stated it was his belief the lightening strike caused an interrupted airflow into the engine resulting in the flameout.

Investigation into the chief pilot's statement revealed a NASA publication entitled: LIGHTNING PROTECTION OF AIRCRAFT, published during October 1977. According to this report, the turbojet engine's flameout is a "...result from disruption of the inlet air by shock wave associated with the lightning arc channel sweeping aft along a fuselage. This channel may indeed pass close in front of an engine intake, and if a restrike occurs, the accompanying shock wave is considered sufficient to disrupt engine operation."