Cessna 172M N61560

Summary

On 21 June 1999 at about 05:20 local time, a Cessna 172M registered N61560, operated by Plus One Flyers Inc., was involved in an accident near San Diego, California, United States. One person was on board and one was seriously injured. The aircraft was destroyed. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

21 June 1999 at 05:20

Classification

Accident

Location

San Diego, California, United States

Nearest airport

Miramar (NKX)

Coordinates

32.7096, -117.1590

Aircraft

Cessna 172M

Registration

N61560

Category

Airplane

Engines

1

Operator

Plus One Flyers Inc.

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Aircraft damage

Destroyed

Weather

VMC

Light

Night/Dark

NTSB number

LAX99LA221

1 person was seriously injured.

The mechanic's improper installation of nonapproved automotive electrical system parts, and his failure to ensure that all electrical connections were secure during the reinstallation, which resulted in the failure of the electrical system. The pilot's becoming lost and disoriented during the subsequent attempt to find an airport on the dark night flight was a factor.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

During a practice instrument approach on a dark night, the aircraft began losing electrical power. The airplane was over a low cloud layer and the pilot cancelled his IFR clearance, informed ATC that he was losing electrical power and that he would fly back to home base under visual flight rules. He then flew in a southerly direction, following roads until he decided that he had flown far enough to locate his home airport. He was unable to locate the airport, made a 180-degree turn in an attempt to locate another airport, and found that he was unsure of his position. He elected to land on a large well-lit parking lot and collided with concrete barriers during the landing roll. An automotive alternator was found installed on the airplane, with a nonapproved support bracket that allowed for pulley misalignment, slack belt tension, and excessive vibration. The voltage regulator, alternator, and associated wiring harnesses were removed for functional testing. The voltage regulator and the alternator as separate units passed functional tests. The power input connector on the regulator fit loosely and allowed an intermittent electrical connection. Failure of the connection would allow the alternator to cease operating. A month prior to the accident, in response to pilot reports of intermittent low system output, a mechanic removed the alternator for repair. The automotive shop that performed the work found the unit had an acceptable voltage output, but the amperage was low. A diode in the bridge rectifier was replaced and the mechanic reinstalled the alternator on the engine. The mechanic said the alternator had been on the airplane for several years and 'it never occurred to [him] to check the Type Certificate Data Sheet' to ensure the alternator was approved for airplanes.

Quoted verbatim from the NTSB record.