ERA11FA312

An in-flight fire that mostly likely occurred in the right front cockpit area behind the instrument panel and below the glare shield; the origin of the fire could not be determined because of the extensive fire damage.

After takeoff, the flight proceeded toward the destination airport and air traffic control communications were transferred between several facilities. While flying at 9,000 feet, the pilot attempted to establish contact with Knoxville Approach Control, but the controller did not reply. About 28 seconds later, the pilot broadcast on the same frequency that he needed to declare an emergency because of a fire but did not specify the location or extent of the fire. There were no further recorded radio transmissions from the pilot, and his declaration of a fire was the first and only transmission describing any abnormal event. Primary radar returns for the airplane depicted a turn to the northeast then north after which the returns were no longer noted. The airplane crashed in a wooded area located about 61 degrees and 3,140 feet from the last primary radar return, using straight line distance. No determination could be made regarding the airplane’s flightpath between the last primary radar return and the accident site; however, witnesses described seeing the airplane turn sharply to the right then hearing an explosion. Structural components consisting of the outer portion of the left wing, right wing outboard of the engine nacelle, vertical stabilizer, rudder, and both horizontal stabilizers were separated from the main wreckage, the farthest of which was located about 400 feet away. Examination of the fracture surfaces of the separated structural pieces revealed no evidence of preimpact failure or malfunction. The cockpit, cabin, instrument panel, nose compartment, empennage, and inboard sections of both wings were nearly consumed by the postcrash fire. The right wing’s upper skin between stations 105 and 115 exhibited fire damage but the lower wing skin just inboard and aft of the structurally separated area did not exhibit any fire damage. This indicates that the fire damage to the upper skin occurred after the lower skin piece separated. Examination of a recovered portion of the instrument panel glare shield revealed thermal damage concentrated around two openings on the right side of the glare shield’s surface. The bottom surface of the glare shield had a distinct area of thermal damage; the damage extended from the forward most area on the right side all the way aft. The severity of the thermal damage was more pronounced in the middle of this area. Photographs of the combustion heater revealed a lack of extensive fire damage and insulation that still covered the conductor on several electrical wires. Further, the surrounding area of the airframe near the heater (for example, the nose landing gear door) did not exhibit extensive fire damage. Therefore, the combustion heater is an unlikely source of the pilot-reported in-flight fire, even though, according to the airplane’s maintenance records, the combustion heater was beyond the recommended overhaul interval specified by the heater manufacturer. The airplane’s maintenance records indicated compliance with a 2008 airworthiness directive (AD) requiring replacement of the circuit breaker toggle switches with switches of an improved design. The AD resulted from reports of overheating of certain circuit breaker toggle switches used in various electrical systems throughout the affected airplanes. Although a portion of the circuit breaker panel from the accident airplane was severely damaged by fire, it did not reveal any signatures consistent with electrical arcing or any other electrical anomaly. The time interval between the pilot’s declaration of an emergency and the last radar return from the airplane was a little less than 1 minute, suggesting that the fire grew quickly without much of an incipient stage. These characteristics are consistent with a fuel-fed fire. Based on localized fire damage to the lower surface of the glare shield, the fire most likely occurred beneath the right side of the instrumental panel, an area that is near the direct-read oil pressure gauges. The exact source of the fire could not be determined because extensive fire damage precluded distinguishing between damage incurred in flight and postcrash.

HISTORY OF FLIGHT On May 25, 2011, about 1613 eastern daylight time, a Hawker Beechcraft Corporation 58, N77AR, collided with mountainous terrain near Murphy, North Carolina. The airline transport pilot and three passengers were fatally injured and the airplane sustained substantial damage. The airplane was registered to Aero Resources Corporation, and operated by Friendship Flying Service, Inc., under the provisions of 14 Code of Federal Regulations (CFR) Part 135 as an on-demand, non-scheduled, domestic passenger flight to Wendell H Ford Airport (K20), Hazard, Kentucky. Visual meteorological conditions prevailed in the area at the time of the accident and an instrument flight rules (IFR) flight plan was filed. The flight originated from Fulton County Airport (FTY), Atlanta, Georgia, about 1543. The flight plan indicated 3 on board; however, the airplane operator reported that an additional individual asked the pilot before departure to be flown to K20. According to a chronological summary of communications, at 1544, the pilot established contact with the Atlanta Terminal Radar Approach Control (Atlanta TRACON) and advised the controller that the flight had departed FTY and was at 1,700 feet. The flight was radar identified and the pilot was cleared to climb to 9,000 feet, which he acknowledged. Air traffic control communications were transferred to Atlanta Air Route Traffic Control Center (Atlanta ARTCC) and the pilot remained in contact with that facility from 1552 to 1611; normal communications were reported. At 1611, the pilot was advised to contact Knoxville Approach Control which he acknowledged. According to a transcription of communications with Knoxville Approach Control, at 1611:50, the pilot established contact with the facility and advised the controller that the flight was at 9,000 feet. The controller did not answer the radio call from the pilot. At 1612:18, the pilot advised the controller, “Knoxville seven seven alpha romeo we gotta declare an emergency got a fire”; but he did not specify the location or magnitude of the fire. The controller asked the pilot if he was going to land at McGhee Tyson Airport (TYS), located in Knoxville, Tennessee. The pilot did not respond and there were no further recorded transmissions from the pilot. According to a NTSB Radar Study that plotted radar targets and displayed key transmissions from the pilot and controller, after the pilot declared an emergency and advised he had a fire, a total of 7 transponder returns were noted. The transponder returns were between 1612:24, and 1612:48. During those 7 returns, the flight proceeded in a north-northeasterly direction with a decrease in altitude noted. The last 2 transponder returns did not have altitude report or had an erroneous altitude report. After the last secondary transponder return, 2 primary radar returns were noted. The second to last primary radar return was noted east-northeast of the last secondary transponder return, and the last primary radar return was located north of the previous primary return. The accident site was located approximately 061 degrees and 3,100 feet from the last primary radar return using straight line distance. No determination was made as to what flight path was made between the last primary radar return and the accident site. The last primary radar return at 1612:57, was located at 35 degrees 11.055 minutes North latitude and 084 degrees 09.7686 minutes West longitude. A witness reported to a Federal Aviation Administration inspector he heard a twin-engine airplane flying overhead his location, and observed the airplane flying straight and level about 1,500 feet above the mountains in a northwesterly direction. The witness reported hearing the engines accelerate and the airplane continued briefly then the right wing dipped and the airplane pitched nose down. While in the nose-low attitude the witness heard the engines accelerate more. He lost sight of the airplane over the ridge and heard an explosion seconds later. He could not see the registration markings or individuals inside, but reported he did not notice any smoke or flames coming from the airplane before losing sight behind the ridge. Another witness who was located at the Unaka Community Cemetery, and who was outside, reported first hearing the airplane. He reported the sound was loud which was what caught his attention and was consistent with a low flying airplane. He pointed out that the airplane was flying towards his position at the cemetery from the approximate location of the Hiwassee Dam Lake (approximately 060 degrees). He did not notice any extreme nose low or nose high pitch position. He noted that the airplane made a “sharp right turn” confirming the direction of the turn. The airplane then went behind trees and he heard an explosion much like a “sonic boom.” He then saw a puff of black smoke. Immediately after the explosion he looked at his watch noting the time of 1618 hours local. Another individual came to the cemetery, and they both went towards the area where they thought the airplane had crashed. They went down Joe Brown Highway, then turned onto Allen Bell Road. They drove to a house close to the crash site and hiked down to a creek. They went into the creek and about 50 to 60 yards downstream, saw smoke to their left. They saw a wing on the right side of the creek as they were walking. When they were about 25 yards from the crash site, he reported there was an explosion. The smoke was intense, and about that time, 1 acre of woods were on fire. He looked at his watch and noted the tine he arrived on-scene was about 1640. He reported the weather conditions were clear and sunny. Still another witness who was located at his house near the crash site reported hearing a low flying airplane with engine surging. He then heard a loud explosion which rattled his windows. He initially thought lightning had struck the house. He went onto his deck, and saw smoke. He and several individuals went to the crash site area and were on-scene about 10 minutes after the crash. When they arrived he noted that the fuselage was on fire, which was not spreading fast. He did not notice anything on fire on his side of the creek. He heard an explosion on the side he was on. A noticed a lot of paperwork with no char marks. The witness reported that there was no rain or breeze at the time, and the clouds were scattered. About 30 minutes after the crash he noted a helicopter was overhead. He estimated the time of the accident about 1615. PERSONNEL INFORMATION The pilot, age 26, held commercial, airline transport pilot, and certified flight instructor (CFI) certificates. At the commercial level he had airplane single engine land rating, and at the airline transport pilot level he had airplane multi-engine land rating issued April 13, 2011. On the CFI, he had airplane single engine and instrument airplane ratings. He held a first class medical certificate with a limitation to wear corrective lenses issued July 12, 2010. On the application for his last medical certificate he listed 2,250 hours as his total flight time. The pilot was hired by Friendship Flying Service, Inc., on March 1, 2009. Paperwork provided by the operator included the pilot’s resume on which he listed a total time of 2,469 hours, 2,370 hours as pilot-in-command, and 652 hours in multi-engine airplanes. The operator submitted a request to the FAA on July 21, 2010, in accordance with the Pilot Records Improvement Act of 1996. The reply to the operator dated August 16, 2010, indicated no legal enforcement actions resulting in a finding of a violation. On July 19, 2010, the pilot submitted to a pre-employment urine test; the results were negative. On September 30, 2010, the pilot completed basic indoctrination, general operation, and aircraft systems training under 14 CFR Part 135. Additionally, on September 30, 2010, October 2, 2010, and on October 4, 20