NTSB Factual Report

On April 5, 2010, at 1233 eastern daylight time (EDT), a Beech 35-A33, N156J, was substantially damaged after catching fire immediately following a, rejected takeoff at Allegheny County Airport (AGC), Pittsburgh, PA. The airplane sustained substantial damage to the fuselage. The private pilot/owner and certificated flight instructor (CFI) were not injured. Visual meteorological conditions prevailed, and no flight plan was filed for the local instructional flight. The flight was conducted under the provisions of 14 Code of Federal Regulations Part 91.

In an interview with the Safety Board, the private pilot stated that the purpose of the flight was for an insurance required proficiency check. He further stated that the CFI had flown the airplane earlier in the day in the local area and had performed two takeoff and landings. After the CFI returned both pilots went to lunch and upon their return, they performed a preflight inspection started the engine, received weather information from the automated terminal information system (ATIS), and then called ground control for taxi clearance.

After performing the pre-takeoff checklist in the run-up area for runway 28, the pilot detected a smell but could not confirm what he smelled. After clearance for takeoff was received from the air traffic control tower and takeoff power was applied, the pilot smelled and visually confirmed smoke coming from the instrument panel area. He immediately aborted the takeoff at a speed no greater than 20 knots, and exited the runway at the next taxiway. After shutting off the master and alternator switches, the smoke continued to emanate from the instrument panel. The pilot shut down the engine and both occupants exited the airplane onto the taxiway. They attempted to extinguish the fire with a hand held fire extinguisher that was obtained from a first response vehicle. The CFI observed the exterior paint begin to blister on the left side of the airplane near the area between the instrument panel and firewall. The Airport Rescue and Fire Fighting personnel arrived and extinguished the fire within a few moments; however, the airplane cabin area had been consumed by fire.

The pilot also stated that the airplane was owned by the Pittsburg Institute of Aeronautics, and the college purchased the airplane approximately six months prior to the accident. The airplane logbooks had been lost prior to the purchase of the airplane and the college attempted to reconstruct the logbooks. The college completed all of the required annual inspections on the airplane. He also mentioned that the college had not completed any work on the avionics or wiring of the airplane since they purchased it.

According to the pilot and Federal Aviation Administration (FAA) records, he held a private pilot certificate with ratings for airplane single-engine, multiengine land, and instrument airplane. His most recent FAA third-class medical certificate was issued on May 11, 2009, and at the time of the accident, he had accrued 387 total hours of flight experience and no hours in the accident airplane make and model.

According to FAA records, the CFI held an airline transport pilot certificate with a rating for airplane single-engine land, a commercial pilot certificate with ratings for airplane multiengine land, rotorcraft-helicopter, glider, and lighter-than-air free balloon, and a flight instructor certificate with ratings for airplane single-engine, multiengine, instrument airplane, and glider. His most recent FAA second-class medical certificate was issued in April 2009, and at that time he reported 25,000 total hours of flight experience.

The airplane was a Beech 35-A33 manufactured in 1961. It was equipped with a Continental Motors IO-470-J series engine and a Hartzell propeller. It was a high performance, all-metal, low-wing, single-engine cantilever monoplane with fully retractable tricycle landing gear.

The 1253 recorded weather observation at AGC, included winds from 250 degrees at 10 knots with gusts of 25 knots, broken clouds at 4,900 feet and 6,000 feet above ground level, 10 miles visibility, temperature 23 degrees C, dew point 12 C, and an altimeter setting of 30.02 inches of mercury.

The airport has two crossing runways designated 10/28 and 13/31. The accident flight was departing off of runway 28 which was a 6,501-foot-long and 150-foot-wide concrete runway. Taxiway A5 was located approximately 350 feet from the beginning of the accident flight takeoff roll.

The sections of the airplane consumed by fire were aft of the firewall including the cabin area and roof structure. Examination of the wreckage by the FAA discovered that the source of the fire began on the left side of the instrument panel, in the vicinity of the communication radios, circuit breakers, and electrical bus bar.

Communiqué No. 116 provided by Hawker Beechcraft Corporation dated June 2008 "ATA24 Electrical Wire Chafing Protection" states in part "Chafing can lead to failed components, inadvertent operation of equipment and the potential for smoke and fire...the factory configuration requires wire bundle protection adjacent to the fuel tube assembly by use of nylon spiral wrap on earlier airplanes or continuous Varglas sleeving on later airplanes...chaffing reports from three main areas; under the instrument panel, in the engine compartment next to the battery box and wiring routed close to fluid tubes. The area under and forward of the instrument panel not only has the greatest concentration of wiring but also has moving components that can damage improperly secured wiring in a very short period of time...there are multiple locations throughout the airplane where wiring and wire bundles are in close proximity to fluid lines where proper security and protection are important to minimize the potential for chafing damage...periodic inspection of wiring is required at each 100 hour or Annual inspection for proper routing and security." According to an email provided by the mechanic, the only maintenance done to the avionics was replacing the altitude encoder. He could not verify if the wires were protected by the sleeving or the wrap and also stated he had not seen the Communiqué before.

NTSB Probable Cause

A fire of undetermined origin behind the left instrument panel.