LONE GROVE, OK, USA
N43763
Piper PA-28R-201T
The airplane impacted trees and terrain following a total loss of engine power and a total loss of electrical power during the cross country flight in dark night conditions. Engine continuity was confirmed and the engine did not exhibit any conditions that would have caused a loss of power. The primary electrical lead from the alternator to the main buss separated at the alternator terminal. NTSB metallurgist found that reconstruction of the broken ends of the alternator cable revealed that the cable was bent through an angle of 90 degrees adjacent to the separation, consistent with deformation associated with the crimping process. A few of the wires contained ductile dimple features on their fractured surfaces and necking down deformation adjacent to the fracture, features indicative of overstress separation. The total usable fuel was 72 gallons. The calculated fuel burn for the flight was 49 gallons.
On January 29, 1998, at 0030 central standard time, a Piper PA-28R-201T single engine airplane, N43763, sustained substantial damage when it impacted trees during a forced landing following a total loss of electrical power and engine power near Lone Grove, Oklahoma. The airplane was operated by a private individual under Title 14 CFR Part 91. The private pilot and the passenger received serious injuries. Night visual meteorological conditions prevailed for the cross country flight and a flight plan was not filed. The flight originated from Scottsdale, Arizona, the previous evening. According to the pilot, the flight departed Scottsdale between 1930 and 2030. Approximately 45 minutes after the departure, the pilot experience intermittent transmit problems with the radios. During the initial descent for the destination airport, the airplane was at 6,500 feet msl when the transponder operated intermittently, the cockpit lights flickered, and the gear warning light illuminated. A voltage check indicated 4 volts at a tachometer reading of 2,300 rpm. When the pilot increased the engine power to 2,575 rpm, the voltage increased to 9 to 10 volts. The pilot had the airport in sight when "the engine began running rough, quit, and everything electrical failed." A flashlight was used to illuminate the airspeed indicator and the altimeter. During the dark night conditions, the pilot observed a car traveling east on Highway 70 and turned the airplane for a forced landing on the highway. When the airplane was 300 to 400 feet agl, the pilot held the airplane in a landing flare attitude until the impact. During personal telephone interviews, conducted by the investigator-in-charge (IIC), and on the Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1/2), the pilot reported that he flew the airplane from the Centennial Airport, Englewood, Colorado, to the Ardmore Downtown Executive Airport, Ardmore, Oklahoma. He made 2 flights in the vicinity of Ardmore and a round trip flight to Gainesville, Texas. The pilot planned a west bound flight from Ardmore to Scottsdale, Arizona, with refueling at Portales, New Mexico. The pilot's estimated time en route at 75 percent power (2,575 rpm, 32 inches manifold pressure, 13 gph) was 5 hours 19 minutes. During the west bound flight, 43.9 gallons of fuel was added at Portales and 59 gallons was added at Scottsdale, Arizona, for a total of 102.9 gallons of fuel for the cross country flight. The flight altitude was 8,500 feet msl from Ardmore to Portales, and 12,500 feet msl to Scottsdale. The pilot planned the return flight to Ardmore at 11,500 feet msl with a 55 percent power setting. The estimated time en route at 2,300 rpm, 27 inches manifold pressure, and 10 gph with winds from 290 degrees at 20 to 26 knots was 4 hours 49 minutes. During a personal telephone interview, conducted by the IIC, the fixed base operator at Scottsdale, Arizona, reported that the airplane was fueled to the tank tabs with 41 gallons at 0406 mountain standard time on January 28, 1998, and topped with 18 gallons at 1630 the same day for a total fuel order of 59 gallons. The pilot paid for the fuel at 1730; however, the actual time of departure was not known. During a telephone interview, conducted by the IIC, and on the enclosed statement, the property owner at the accident site reported that he was qualified as a fireman, paramedic, and emergency rescue person. He stated that he did not hear any engine sounds. He was awakened by a noise and the pilot's knock on his door. The pilot reported to the property owner that he was trying to "land the aircraft on the highway and over shot by approximately 50 feet, and crashed in the trees." The property owner assisted the pilot and passenger, and notified local authorities for emergency transportation. The airplane came to rest approximately 160 feet from the property owner's house. The fuel system was compromised and fuel was leaking from the right wing area that separated from the airframe. The emergency locator transmitter (ELT) was disconnected and removed from the aircraft. There was less than one gallon of fuel removed from the airplane. During the recovery process by the retrieval crew, approximately 1.5 gallons of fuel was drained from the left wing of the aircraft. Local authorities and the FAA inspector, who responded to the site, reported that there was no physical evidence of fuel at the site. Fuel tanks were deformed and their integrity was compromised. During personal telephone interviews, conducted by the IIC, the flight school and the pilot's flight instructor reported that the pilot had approximately 155 hours of flight time when he enrolled in the Private Pilot Certification Course at Altitudes Flight School, Centennial Airport, Englewood, Colorado. The pilot had flown approximately 24 hours as a student at Altitudes. The pilot received his private pilot certificate on January 15, 1998. According to the flight instructor, the private pilot had received dual instruction in the PA-28R-201T airplane and a complex endorsement in his logbook. The instructor estimated that the pilot had 25 to 30 hours of complex aircraft time. The flight instructor contacted the owner of N43763, requested, and received authorization from the aircraft owner for the pilot to fly the airplane (N43763) round trip from Englewood, Colorado, to Ardmore, Oklahoma, with a return to Englewood. A review of the flight instructor's logbook, by the IIC, revealed that the pilot had received 5.4 hours of dual instruction in a PA-28R-201T aircraft from October through January 24, 1998. Dual instruction in the make and model of aircraft (N43761) on October 5, 1997, was a 1.9 hour cross country flight of which 1 hour was conducted at night. The pilot received a 0.9 hour dual instructional flight in N43763 on January 24, 1998. A review of the maintenance records by the IIC revealed a standard airworthiness certificate was issued on August 15, 1977. In October 1995, the engine was disassembled and reassembled IAW Continental overhaul manual. The Gill G-35 battery was installed on December 10, 1996. At the last 100 hour inspection, performed on September 10, 1997, the tachometer reading was 3,926.76 hours. During personal telephone interviews, conducted by the IIC, the airplane owner that he was contacted by the flight instructor, he gave permission on the morning of January 28, 1998, for the private pilot to fly the aircraft to Ardmore, Oklahoma, for the weekend. The owner reported the total usable fuel as 72 gallons with a fuel burn of 12 gph at 2,400 rpm and 30 inches manifold pressure. ATC Data Analysis Reduction Tool (DART) radar data provided by Albuquerque Air Route Traffic Control Center (ARTCC) was reviewed by the IIC. Information provided by the pilot, ATC data, winds aloft data, and aircraft performance data, were used to calculate the fuel burn for the flight from Scottsdale to Ardmore at 49 gallons. During telephone interviews, conducted by the IIC, personnel of the ATC Quality Assurance Staff (Southwest Region and Western Region) stated that a weather briefing was not requested for the flight. En route the aircraft received VFR flight following from Albuquerque ARTCC. The airplane was examined under the surveillance of the IIC on February 12, 1998, at Lancaster, Texas. The tachometer reading was 4,170.34 hours. Flight control system continuity was confirmed. Fuel system line integrity and operation of the fuel selector valve were verified by supplying the system with air pressure. The electrical fuel boost pump was operationally checked and residual fuel was noted from the fuel injector supply line. Examination of the electrical system found the primary electrical lead from the alternator to the main buss separated at the alternator terminal crimp. The alternator cable and terminal crimp were forwarded to the NTSB Metallurgical Laboratory for further examination. The Gill G-35 (S/N G01642742) battery was removed and found to be at 11.7 volts and when loaded dropped to 3.41 volts in 10 seconds. A charge of 15 amps was supplied to the battery for 3 hours and 35 which charged the battery to 13.2 volts. When an electrical load was applied to the battery, the voltage dropped from the 13.2 volts to 10.7 volts in 3 seconds. When the alternator was operationally rotated, the cockpit electrical system gauges and lights operated. The NTSB metallurgist found that reconstruction of the broken ends of the alternator cable revealed that the cable [lead] was bent through an angle of 90 degrees adjacent to the fitting [terminal crimp]. The majority of the separated wires of the cable had "flat sides adjacent to the separation, consistent with deformation associated with the crimping process. A few of the wires contained ductile dimple features on their fractured surfaces and necking down deformation adjacent to the fracture, features indicative of overstress separation." Engine continuity was confirmed to all the cylinders and the accessory case. The engine and accessories were forwarded to Teledyne Continental Motors, Mobile, Alabama, for further examination. The engine and accessories were examined on July 27, 1998, at Mobile, Alabama, under the surveillance of a NTSB investigator. According to the manufacturer representative, the engine "exhibited normal operational signatures throughout. All internal components appeared well lubricated. This engine did not exhibit any condition that would have caused an operation problem." According to the turbocharger manufacturer, "no pre-accident conditions were found during the inspection of the turbocharger and the associated controls which would have interfered with normal operation." The airplane was released to the owner.
The total loss of engine power for an undetermined reason. Factors were the total loss of electrical power resulting from a separated alternator cable due to improper maintenance by unknown maintenance personnel, the lack of suitable terrain for the forced landing, and the dark night conditions.
Source: NTSB Aviation Accident Database
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