- Date
- October 15, 1991, 16:55 local (Oct 16, 1991, 00:55 UTC)
- Place
- Montague Island, AK
- Injuries
- 1 minor
- Damage
- Substantial damage
- Phase of flight
- Enroute
- Aircraft
- N3850ZPiper PA-18
- Weather
- Visual (VMC) · Day
- Status
- Completed · report May 3, 1993
- Report
- Approved by Office Director
- NTSB office
- Alaska Regional Office
- FAA report
- 19911015046529A
- Case key
- 5637
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 NTSB’s determination of the probable cause, and any contributing factors.
The power loss due to the crankshaft failure. Contributing to the accident was improper maintenance during the last engine overhaul.
Analysis
During cruise flight, the engine seized without warning. With no suitable landing area on the beach, the pilot ditched in the ocean and swam ashore about 1/2 mile away. An investigation revealed that the crankshaft had broken at the forward cheek of the #3 main bearing. A reddish sealant residue was found around the main bearing thru stud holes of the crankcase. According to Lycoming service instruction #1125A, sealant should not have been applied in this area.
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.
Aircraft
- Registration
- N3850Z
- Reported as
- Piper PA-18
- Category
- Airplane
- Serial number
- 18-7608
- Airframe hours
- 1,653
- Engine
- Lycoming O-320-B2B, 160 horsepower, reciprocating
- Damage
- Substantial damage
- Flight
- Business · Part 91
- Operator
- Monnett, Charles W.
- Registered owner
- Monnett, Charles W.
- Airworthiness certificate
- Standard, Normal
- Last inspection
- Annual · February 18, 1991 · 63 hours before
- Departed
- CDV · Cordova, AK
- Destination
- CDV · Cordova, AK
- Flight plan
- VFR
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
- 42
- Certificate
- Commercial
- Airplane ratings
- Single-engine land
- Medical
- Class 2, Valid Medical--no waivers/lim.
- Seat
- Front
- Flight hours
- 1,000 total · 75 in this make and model · 950 as pilot in command · 100 in the last 90 days · 40 in the last 30 days · 4 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 120° at 2 knots
- Visibility
- 50 statute miles
- Lowest ceiling
- None
- Temperature
- 39 °F
FAA reports on this event · 1
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.