OLD FORGE, PA, USA
N70CM
Cessna 310N
Several witnesses saw the airplane before impact, and heard engine noise oscillating between no power and high power. Examination of the wreckage revealed that the two main fuel tanks were ruptured and charred, but the two auxiliary fuel tanks were not compromised, and appeared absent of fuel. Only drops of fuel were found in the mechanical fuel pumps, fuel lines from the pumps to the mixture controls, and the fuel lines from the mixture controls to the injection manifolds. Examination of the airframe, engines, and propellers, did not reveal any pre-impact mechanical malfunctions. Review of the fueling records revealed that all four tanks were completely fueled about 1 month prior to the accident. The airplane was operated several times after that fueling, and fuel was added to the main fuel tanks on four occasions before the accident. However, fuel was never added to the auxiliary fuel tanks. Although both auxiliary fuel tanks appeared absent of fuel at the accident site, the investigative team was unable to confirm the fuel selector positions prior to impact. The flight instructor had about 50 hours of flight experience in the make and model accident airplane, and the pilot/owner had about 100 hours of flight experience in the accident airplane.
HISTORY OF FLIGHT On January 6, 2000, at 1734 Eastern Standard Time, a Cessna 310N, N70CM, was substantially damaged when it descended into terrain at Old Forge, Pennsylvania, while on approach to Wilkes-Barre/Scranton International Airport (AVP), Wilkes-Barre, Pennsylvania. The certificated flight instructor and private pilot/owner were fatally injured. Visual meteorological conditions prevailed, and no flight plan was filed for the multi-engine instructional flight conducted under 14 CFR part 91. According to a Federal Aviation Administration (FAA) inspector, and review of recorded transmissions between N70CM and the AVP control tower; the pilots departed AVP about 1520, and flew to Tweed-New Haven Airport (HVN), New Haven, Connecticut. They completed one instrument approach to HVN, but did not land. They then flew to the Lake Henry VOR, and made a low pass over the flight instructor's private airstrip. The pilots returned to AVP and performed two touch and go landings to Runway 22. During the approach to a third landing, the following transmissions were recorded: 1734:03 N70CM "tower er we got a problem here seven zero charlie mike" 1734:08 ATC "what would you like to do sir" 1734:11 N70CM "we are trying to get it straightened out" 1734:14 ATC "roger that sir you are still cleared to land" 1734:35 ATC "hey charlie mike is there anything i can do for you" 1734:36 N70CM "...no not yet sir" There were no more recorded transmissions from N70CM. Two witnesses reported hearing the engines revving, "like a snowmobile in the distance." They stated that during a 5-6 second period, about 3 times, the engines sounded "as if they were coughing." Then there was silence, followed by a loud revving sound. A third witness stated: "...I saw an airplane flying low, I heard the engine sputtering on the aircraft, and then it had cut out. I then heard the engine come back on again and then it had cut out for a second time, the engine had caught and then it had cut out for the third and final time, I could see the plane drifting and in a split second the plane had done a nose dive..." According to video provided by a local news station, the airplane appeared to be in a slight right turn, and nose down, as it descended below the tree line. The accident occurred during the hours of night; located approximately 41 degrees 21.62 minutes north longitude, and 75 degrees 43.58 minutes west latitude. PERSONNEL INFORMATION The flight instructor held an airline transport pilot certificate and flight instructor certificate, with ratings for multi-engine land and instrument airplane. According to his logbook, he had a total flight experience of approximately 2,900 hours, of which, about 50 hours were in the accident airplane. Additionally, he had approximately 223 hours of experience as a flight instructor. The flight instructor's most recent FAA first class medical certificate was issued on December 16, 1999, with no restrictions The pilot receiving instruction held a private pilot certificate, with ratings for single engine land and instrument airplane. According to his logbook, he had a total flight experience of approximately 707 hours, of which, about 104 hours were in the accident airplane. The pilot's most recent FAA third class medical certificate was issued on September 29, 1998, with a restriction for corrective lenses. AIRCRAFT INFORMATION The airplane's last annual inspection was completed on December 1, 1999. Since the inspection, the airplane had approximately 9.1 hours of operation. The airplane was equipped with two main fuel tanks, one for each engine, located at the wingtips. Each main tank had a 51-gallon capacity, of which, 50 gallons were useable. The airplane was also equipped with two auxiliary fuel tanks, located at the inboard section of the wings. Each auxiliary tank had a 20.5-gallon capacity, of which, 20 gallons were useable. The airplane was not equipped with optional winglocker tanks. WRECKAGE DESCRIPTION The wreckage was examined at the accident site from January 6 through January 8. It was observed intact, approximately 30 degrees nose down into a berm, and oriented about a 105-degree magnetic heading. The accident site was about 1 mile north of AVP. All major components of the airplane were accounted for at the accident site. Flight control continuity was confirmed from all control surfaces to the forward cabin area. The right wing sustained impact damage to the leading edge. The aileron was slightly deflected downward. The flap was partially extended, about 15 degrees. The wingtip was separated from the wing. It was observed crushed and charred. The inboard auxiliary fuel tank was intact, and no fuel was observed in the tank. The landing gear was in the retracted position. The empennage, aft of the cargo door, was undamaged. It was inline with the fuselage, and no twisting or cantering was observed. The elevator was slightly deflected downward, and the rudder was slightly deflected to the left. The left wing was partially separated at the root, bent forward, and lying on top of a fallen tree. There was impact damage to the leading edge. The aileron was deflected upward, and the flap was extended approximately 15 degrees. The wingtip was separated from the wing. It was observed crushed and charred. The inboard auxiliary fuel tank was intact, and no fuel was observed in the tank. The cockpit area was crushed and buckled. The fuel selectors were not visible. The linkage in both wings indicated that both selectors were in the "OFF" position, after impact. When the wreckage was recovered from the berm; the left fuel selector was observed in the "LEFT AUX" position, and the right fuel selector was in the "LEFT CROSSFEED" position. The throttle levers, propeller levers, and mixture controls were in the forward positions. The left fuel boost pump was observed in the "LOW" position, and the right fuel boost pump was observed in the "HIGH" position. Both propellers were found attached to their respective engines, and partially buried approximately 2 feet into the berm. One blade from each propeller was not buried, and appeared undamaged. After recovery, the two blades from each propeller that were buried, were bent aft. None of the blades exhibited S-bending or twisting. The left propeller governor was destroyed, and the right propeller governor was retained for further examination. The valve covers and top spark plugs from both engines were removed for inspection. Oil was present on the rocker-arms and valves. The spark plug electrodes were intact, absent of debris, and light gray in color. Both engines were rotated by hand. Valve train continuity was confirmed, and thumb compression was attained on all cylinders. The fuel injection manifold covers were removed from both engines, and some fuel was present. The mechanical fuel pumps from both engines were removed and inspected. There was no visible damage to the pumps or the couplings. The mixture control units of both engines were examined, and both appeared to be in the full power position. Only a few drops of fuel were present in the mechanical fuel pumps, and in the fuel lines from the pumps, to the mixture controls, to the injection manifolds in both engines. Additionally, a witness at the accident site stated that he did not smell fuel. He extinguished both wingtip fires with two handheld fire extinguishers. MEDICAL AND PATHOLOGICAL INFORMATION Autopsies were performed on the flight instructor and pilot by Pathology Associates of N.E. Pennsylvania, on January 7, 2000. Toxicological testing was conducted at the FAA Toxicology Accident Research Laboratory, Oklahoma City, Oklahoma. Testing performed on the flight instructor revealed: "EPHEDRINE detected in Urine" "PSEUDOEPHEDRINE detected in Urine" "PHENYLPROPANOLAMINE detected in Urine" Testing performed on the private pilot was negative for drugs and alcohol. TESTS AND RESEARCH A cassette tape copy of recorded transmissions, between N70CM and the AVP control tower, was sent to the Safety Board's Audio Laboratory for a Sound Spectrum Study. The purpose of the study was to isolate background noise, and attempt to calculate propeller RPM. According to the study: "Although the signals present in the transmissions are distinct, the source of the signals could not be unequivocally identified-that is, the signals were attributed to propeller noise, thereby resulting in a calculated engine speed. Specifically, Transmission 1 occurred after N70CM performed a touch and go landing and its corresponding signature results in an engine speed of 2424 RPM. As the aircraft continued in the airport traffic pattern and transmitted normally (Transmissions 2-7), the signatures indicate an average engine speed of about 2300 RPM. The last transmissions, in which the pilot indicated that there was a problem, contain signatures that correspond to an engine speed as high as 2526 RPM. The Safety Board Specialist could not positively determine if one or two propellers were contributing to the signals, but there was no indication that an engine had slowed or stopped during the transmissions, and a second set of signals was not detected. On February 2, 2000, the wreckage was re-examined at Universal Loss Management, Saint Louis, Missouri, under the supervision of a FAA inspector. The inspector stated that a 24-volt DC power supply was connected to each engine's starter, one at a time. When both crankshafts were rotated via the starter motor, all ignition leads produced a visible spark. On February 8, 2000, the right propeller governor was examined at Woodward Governor Company, Rockford, Illinois, under the supervision of a FAA inspector. According to the examination report, "Nothing was found which would indicate that the unit was not operating as intended." On May 8, 2000, both propellers were examined at McCauley Propeller Systems, Vandalia, Ohio, under the supervision of a FAA inspector. According to the McCauley Propeller Systems report, both propellers possessed similar energy at impact. Both were being operated under conditions of low power, near or at the low pitch range. Additionally, examination of the feather stop mechanisms revealed that they were not engaged at the time of the accident. There was no evidence of any failure of the propellers, and all damage appeared to be impact related. FUELING RECORDS According to an airplane time sheet and the Hobbs meter, the duration of the accident flight was approximately 2.4 hours. Review of the Cessna 310N Owner's Manual revealed a cruise performance chart for normal lean mixture at 2,500 feet. According to the chart, an rpm setting of 2,450 with a manifold pressure setting of 24, yielded a 28.0 gallon-per-hour fuel burn (14.0 gallons per engine). The fueling records for N70CM were obtained from the operator. On December 3, 1999, a request to "TOP ALL TANKS" was submitted to the operator, and 86.1 gallons of fuel were added to the airplane. After 1.4 hours of operation, on December 12, 1999, a request to "TOP MAIN (TIP) TANKS" was submitted to the operator, and 19.0 gallons of fuel were added to the airplane. After 1.3 hours of operation, on December 17, 1999, a request to "TOP BOTH MAINS (TIPS)" was submitted to the operator, and 18.9 gallons of fuel were added to the airplane. After 1.1 hours of operation, on December 27, 1999, a request to "TOP BOTH MAINS (TIPS)" was submitted to the operator, and 19.9 gallons of fuel were added to the airplane. After 1.4 hours of operation, on December 30, 1999, a request to "TOP BOTH MAINS (TIPS) was submitted to the operator, and 23.5 gallons of fuel were added to the airplane. After December 3, 1999, there was no record of the auxiliary tanks being fueled. Although the auxiliary tanks were empty at the accident scene, the investigative team could not confirm that the tanks were selected when the accident occurred. ADDITIONAL INFORMATION Although the linkage for both fuel selectors corresponded to the "OFF" position, a representative from the airplane manufacturer stated that it was common for the linkage to be forced into the "OFF" position when subjected to impact forces. The wreckage was released to the TEEM Environmental Company Operations Manager on January 8, 2000.
Both pilots' failure to adequately manage the fuel supply, which resulted in fuel starvation.
Source: NTSB Aviation Accident Database
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