- Date
- August 29, 1989, 19:45 local (Aug 30, 1989, 00:45 UTC)
- Place
- Moose Lake, MN
- Injuries
- 2 fatal
- Damage
- Destroyed
- Phase of flight
- Enroute
- Aircraft
- N2841PPiper PA-20
- Weather
- Visual (VMC) · Day
- Status
- Completed · report December 10, 1990
- Report
- Approved by Office Director
- FAA report
- 19890829032469A
- Case key
- 34694
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
Severe corrosion of the lower forward lift strut for the right wing, inadequate inspection of the lift strut by maintenance personnel, and subsequent failure of the lift strut, which resulted in an overload failure (folding back) of the wing. Related factors were: inadequate inspection procedures provided by the manufacturer & inadequate surveillance by the FAA.
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 acft (Piper PA-22, converted to a PA-20, iaw STC SA45AM) was being used to provide a biennial flt review for the owner/plt (considered as PIC on this flt). Drg flt, the rgt wing folded back over the fuselage & the acft crashed. An exam of the wreckage revealed the fwd lift strut for the rgt wing had failed in an area of severe corrosion. The failureoccurred at the lower part of the lift strut near the fuselage attachment point. An exam of the annual inspn checklist indcd all applicable airworthiness directives (ad's) were complied with as of 7/21/89 & that the lift struts were visually inspd at the annual inspn. The acft logbook showed that AD 77-03-08 (requiring mechanical testing of the lift strut for evidence of corrosion at 5 yr intervals) had been complied with in July 1988. The aroma of linseed oil was noted in all lift struts, but polymerized linseed oil was found in the rgt & left rear struts. Internal corrosion had perforated the rgt fwd lift strut prior to its failure.
Aircraft
- Registration
- N2841P
- Reported as
- Piper PA-20
- Category
- Airplane
- Serial number
- 22-3138
- Engine
- Lycoming O-360-A4A, 180 horsepower, reciprocating
- Damage
- Destroyed
- Flight
- Instructional · Part 91
- Operator
- Prachar, Kenneth M
- Registered owner
- Prachar, Kenneth M
- Airworthiness certificate
- Standard, Normal
- Last inspection
- Annual · July 21, 1989
- Departed
- 21Y · Moose Lake, MN
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
- 44
- Certificate
- Private
- Airplane ratings
- Single-engine land
- Medical
- Class 3, Valid Medical--no waivers/lim.
- Seat
- Left
- Toxicology
- Performed
- Flight hours
- 246 total · 218 in this make and model
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 360° at 19 knots
- Visibility
- 15 statute miles
- Lowest ceiling
- None
- Temperature
- 61 °F, dew point 57 °F
- Altimeter
- 29.00 inHg
- Observed at
- DLH, 38 nm away
FAA reports on this event · 1
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.