- Date
- September 2, 1989, 00:00 local (07:00 UTC)
- Place
- California City, CA
- Injuries
- 2 fatal
- Damage
- Destroyed
- Phase of flight
- Enroute
- Aircraft
- N393DRuppercht Varieze
- Weather
- Visual (VMC) · Day
- Status
- Completed · report July 22, 1992
- Report
- Approved by Office Director
- FAA report
- 19890902033249A
- Case key
- 26147
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 wing failed due to the pilot/owners overtorquing the wing bolts and the improper installation of the wing attach plates/cones.
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 pic/owner/builder departed California City, CA, on a local personal flight. A gnd witness reported the airplane was at a high altitude in level flight when suddenly the wings folded. The airplane then descended out of control into a lake bed. Wreckage examination disclosed that one set of the wing attachment plate taper cones and the retaining bolts were missing. The remaining taper cones were not seated properly and the retaining bolts were stretched and necked down which are charteristic of overtorquing. The remaining bolts appeared to have been overtorqued in order to seat their respective attach cones.
Aircraft
- Registration
- N393D
- Reported as
- Ruppercht Varieze
- Category
- Airplane, amateur-built
- Serial number
- 393
- Airframe hours
- 149
- Engine
- Continental O-200, 100 horsepower, reciprocating
- Damage
- Destroyed
- Flight
- Personal · Part 91
- Registered owner
- Myron S. Rupprecht
- Airworthiness certificate
- Special, Experimental (Special)
- Last inspection
- Annual · May 20, 1989
- Departed
- L71
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
- 59
- Certificate
- Commercial
- Airplane ratings
- Single-engine land
- Medical
- Class 3, Valid Medical--w/ waivers/lim
- Toxicology
- Performed
- Flight hours
- 1,691 total · 152 in this make and model · 1,600 as pilot in command · 5 in the last 90 days · 3 in the last 30 days
Weather
- Conditions
- Visual (VMC) · Day
- Lowest ceiling
- None
FAA reports on this event · 1
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.