- Date
- January 6, 1990, 17:02 local (Jan 7, 1990, 01:02 UTC)
- Place
- Santa Ana, CA
- Injuries
- 1 minor
- Damage
- Substantial damage
- Phase of flight
- Approach
- Aircraft
- N74520Mooney M20B
- Weather
- Visual (VMC) · Day
- Status
- Completed · report October 2, 1992
- Report
- Approved by Office Director
- FAA report
- 19900106000199A
- Case key
- 26717
From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.
On this page
Probable cause
The failure of bolts retaining the idler shaft allowing the cam shift timing to change and by its failure to drive the left magneto.
Sequence of events
NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.
Analysis
The engine on a Mooney M20B failed while on short final approach. Examination revealed that the bolts retaining the idler shaft had sheared allowing a change in the internal timing and failure to drive the left magneto. Both bolt heads, the lockplate, and the cotter keys were found in the oil sump. The ignition springs on the electrical harness had evidence of arcing.
Aircraft
- Registration
- N74520
- Reported as
- Mooney M20B
- Category
- Airplane
- Serial number
- 1907
- Engine
- Lycoming O-360-A1D, 180 horsepower, reciprocating
- Damage
- Substantial damage
- Flight
- Personal · Part 91
- Operator
- Robley D. Mc Cants
- Departed
- SNA
- Destination
- SNA
- Airport
- SNA · John Wayne, runway 19, 5,700 × 150 ft, macadam
Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.
Flight crew
As NTSB recorded them. NTSB leaves out names.
- Role
- Pilot
- Age
- 40
- Certificate
- Private
- Airplane ratings
- Single-engine land
- Medical
- Class 3, Valid Medical--w/ waivers/lim
- Flight hours
- 557 total · 86 in this make and model
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 190° at 5 knots
- Visibility
- 5 statute miles
- Lowest ceiling
- None
- Temperature
- -0 °F, dew point -0 °F
FAA reports on this event · 1
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.