Aviation Accident Summaries

Aviation Accident Summary LAX97FA123

PACOIMA, CA, USA

Aircraft #1

N3030H

Ercoupe (Eng & Research Corp.) 415-D

Analysis

While on a downwind departure, the pilot declared an emergency and requested an immediate landing. He was cleared to land on any runway. The pilot turned a close base entry to his departure runway, and the turn continued into a descending spiral to impact. Tower personnel observed smoke trailing from the aircraft at the time of the emergency. Postaccident examination revealed an improperly installed electrical system, which lacked circuit protection and proper use of aviation type wire.

Factual Information

HISTORY OF FLIGHT On March 15, 1997, at 1448 hours Pacific standard time, an Ercoupe 415 D, N3030H, operated by the pilot, was destroyed during an emergency landing approach at Pacoima, California. The pilot succumbed to his injuries while in the hospital, and the passenger was fatally injured. Visual meteorological conditions prevailed for the personal flight and no flight plan was filed. The flight originated at 1445 from Pacoima, and was destined for Oakland, California. According to air traffic control tower personnel, the pilot requested a downwind departure from runway 12. When the aircraft was abeam of the tower north, the pilot stated "we've got an emergency, we need to land." Tower personnel cleared the pilot to land on any runway, and noticed black smoke trailing from the aircraft as it started to turn base leg for runway 12. According to the control tower chief, the pilot flew the downwind leg about 1,700 to 1,800 feet msl. The normal pattern altitude is 2,000 feet msl. The quality of the aircraft radio remained good throughout the emergency. As the aircraft turned downwind to base, it continued into a descending left spiral to impact. According to the tower chief, the pilot remained composed and, as a result, he assumed it to be a routine or non-life threatening emergency, and immediately alerted the airport personnel. PERSONNEL INFORMATION The pilot's logbook was recovered from the wreckage. According to the fire damaged logbook, he had accumulated about 428 hours of flight time. AIRCRAFT INFORMATION The aircraft was certificated on September 26, 1946. On September 20, 1963, the airplane received major damage repairs to the lower forward fuselage area. At that time, both metal wings were replaced with fabric covered wings and the model was changed from a 415-C to a 415-D. According to the aircraft logbook, the last annual inspection was completed on October 3, 1996. At that inspection the aircraft total time was listed as 2,221.0 hours. On December 15, 1982, the original Continental C-85 engine with a generator and 85 horsepower engine was replaced with a Continental O-200 providing 100 horsepower and an alternator. The Federal Aviation Administration (FAA) approval for the installation was under Supplemental Type Certificate (STC) SA-2628-WE. The STC required the electrical system to be reworked per the STC holders drawing TAS-415-3. On October 5, 1985, an ARNAV model R21DB loran was installed. On December 5, 1985, a model A/200 VHF com/nav radio was removed. A model TX-720 VHF com and an R-250 transponder, an altitude digitizer, a marker beacon, an omni bearing selector, and antennas were installed. On June 9, 1986, a throttle quadrant modification was made to the instrument panel area, updating the airplane to a later configuration. On June 10, 1986, the battery was removed from the factory location in the baggage compartment and relocated to the forward side of the firewall. The installation was approved for return to service by an FAA licensed airframe mechanic holding an inspection authorization. The FAA approved data was listed as FAA Advisory Circular (AC) 43.13-2A and chapter 10 and 11 of AC43.13-1A. A June 10, 1986, logbook entry references an FAA Field Approval of the above item by the Farmingdale General Aviation District Office (GADO). That approval was not found in the aircraft paperwork. The aircraft electrical system had been changed from the original. The electrical switches had been replaced with circuit breaker switches. Strobe lights had been installed in three positions. The electrical master switch had been changed and relocated. According to information obtained during the investigation, the owner/pilot was doing his own maintenance where approved, and under the supervision of a licensed maintenance technician when required. METEOROLOGICAL INFORMATION At 1140 on the morning of the accident, the pilot called the FAA Hawthorne Automated Flight Service Station and obtained a preflight weather briefing for a flight from Whiteman to Oakland. At 1447, Whiteman Airport was reporting: wind direction 150 degrees at 10 knots; visibility 5 statute miles in haze; scattered clouds at 20,000 feet msl; temperature 75 degrees Fahrenheit; and the altimeter was 29.87 inHg. MEDICAL AND PATHOLOGICAL INFORMATION The pilot succumbed to his injuries while still in the hospital several days after the accident. There was no toxicological analysis performed. TESTS AND RESEARCH An on-scene and postaccident examination/reconstruction was conducted. Assisting in the examination were representatives from Continental Motors and an aircraft electrical system technician. A postaccident fire had consumed a major portion of the fuselage. The airplane service manual electrical system schematic did not compare with this airplane because the airplane had been changed and modified many times over the 50 years of it's existence. During the attempted reconstruction of the electrical system, two runs of 11 gauge copper sheathed (shielded) wires were found and traced. Examination of the wires revealed a frayed/worn through section that matched an area of the firewall penetration hole. At another location on the wire was multistrand copper wire that had become molten and necked down to a break. The two 11 gauge wires were located on the battery side of the master relay and were without circuit protection. Internal examination of the alternator revealed that the filter capacitor had failed under an electrical load, characteristic of an electrical overload and consistent with a dead short in the circuit. ADDITIONAL INFORMATION Examination of the fuselage fuel tank revealed several attempts to repair fuel tank leaks with at least two types of materials. One type was an integral tank sealant and another was a fiber glass type material. Fuel dye type stains were found on the bottom of the tank and the tank supply fitting. The tank is located above all electrical wiring. The wreckage was released to the insurance company representative on October 9, 1997.

Probable Cause and Findings

improper maintenance/installation of electrical wiring, the lack of circuit protection, and subsequent in-flight electrical fire.

 

Source: NTSB Aviation Accident Database

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