- Date
- April 24, 1990, 13:50 local (18:50 UTC)
- Place
- West Bend, WI
- Injuries
- 2 fatal
- Damage
- Destroyed
- Phase of flight
- Other
- Aircraft
- N2976RBellanca 8KCAB
- Weather
- Visual (VMC) · Day
- Status
- Completed · report January 23, 1992
- Report
- Approved by Office Director
- Safety recommendations
- Yes
- FAA report
- 19900424014939A
- Case key
- 14528
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
Inflight failure of the right wing strut-to-spar attachment fitting due to fatigue initiated by improper welding techniques involving inadequate post-weld cooling control.
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 right wing separated from the aircraft during an instructional aerobatic flight. Metallurgical examination revealed that the right wing's lift strut-to-wing spar attachment fitting had failed due to fatigue progression in both side plates of the fitting. The initiation areas were immediately adjacent to the ends of two welds. In the weld heat affected zone, the microstructure transitioned from a spheroidized pearlite region near the base metal into a coarse tempered martensite region adjacent to the fusion zone.
Aircraft
- Registration
- N2976R
- Reported as
- Bellanca 8KCAB
- Category
- Airplane
- Serial number
- 624-80
- Airframe hours
- 1,775
- Engine
- Lycoming AEIO-360-H1A, 180 horsepower, reciprocating
- Damage
- Destroyed
- Flight
- Instructional · Part 91
- Operator
- Gran-Aire, Inc.
- Airworthiness certificate
- Standard, Aerobatic
- Last inspection
- Annual · February 26, 1990 · 50 hours before
- Departed
- MWC · Milwaukee, WI
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
- 47
- Certificates
- Flight instructor, Commercial
- Airplane ratings
- Single-engine land, Multi-engine land
- Instrument ratings
- Airplane
- Medical
- Class 2, Valid Medical--w/ waivers/lim
- Toxicology
- Performed
- Flight hours
- 26,000 total · 4,000 in this make and model · 25,600 as pilot in command · 65 in the last 90 days · 25 in the last 30 days · 5 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 210° at 10 knots
- Visibility
- 7 statute miles
- Lowest ceiling
- None
- Temperature
- 82 °F, dew point 37 °F
- Altimeter
- 29.00 inHg
- Observed at
- MWC, 15 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.