# NTSB CHI88FA240: Bellanca 8KCAB, N50702, Oswego, IL, September 20, 1988

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: September 20, 1988, 18:25 local (23:25 UTC)
- Place: Oswego, IL
- Coordinates: 41.689548, -88.32904 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=41.6895&lon=-88.3290&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 1 fatal
- Status: Completed, report January 31, 1990
- Report: Approved by Office Director
- Safety recommendations: Yes
- NTSB case key (mKey): 13973
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI88FA240
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/13973/pdf
- Page: https://openairdocs.org/ntsb/CHI88FA240

## Probable cause

INADEQUATE DESIGN INTHE MANUFACTURE OF THE PILOT'S SEAT WHICH FAILED DURING INTENTIONAL AEROBATIC MANEUVERS FOR WHICH THE AIRCRAFT INCLUDING THE SEAT WERE INTENDED.

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- Airframe/component/system failure/malfunction, maneuvering
  - aerobatics - initiated, pilot in command
  - fuselage,seat - worn (contributing factor)
  - fuselage,seat - failure,total (cause)
  - acft/equip,inadequate design, manufacturer (contributing factor)
  - flt control syst,elevator control - disabled (cause)
  - design stress limits of aircraft - exceeded (contributing factor)
  - wing - failure,total
  - wing - separation
- In flight collision with terrain/water, descent - uncontrolled

## Analysis

DRG AEROBATICS, THE ACFT WENT IN A DIVE, GAINED SPEED, LEVELED OFF & PULLED UP ABRUPTLY. DRG THE PULL-UP, THE RGT WING FAILED UPWARD & SEPD FM THE ACFT. THE ACFT THEN WENT OUT OF CTL & CRASHED. THE PLT WAS WEARING A PARACHUTE, BUT DID NOT BAIL-OUT; HE WAS FOUND STRAPPED IN HIS SEAT & THE DOOR RLS PIN WAS STILL IN PLACE. THERE WAS EVIDENCE OF UPWARD BENDING OF THE LEFT WING; BOTH HORIZONTAL STABILIZERS HAD EVIDENCE OF BEING COMPROMISED IN A DWNWRD DRCTN. AN EXAM OF THE PLT'S SEAT REVEALED THE TUBULAR ENDS OF THE SEAT-BACK FRAME HAD FAILED AT THE PIVOT POINTS (PVT PTS), WHERE THE SEAT-BACK WAS DESIGNED TO PIVOT FWD OVR THE SEAT PAN TO ALLOW ENTRY TO THE AFT SEAT. ATTACHING BOLTS AT THE PVT PTS HAD PULLED THRU THE ENDS OF THE FRAME. EVIDENCE OF OVERSTRESS SHEAR WAS FND AT THE RGT PVT PT AS IF THE SEAT-BACK HAD FAILED AFT. EVIDENCE OF OVERSTRESS SHEAR & TWISTING DEFORMATION WAS FND AT THE LEFT PVT PT. BELLANCA 7 & 8 SERIES ACFT HAVE HAD SVRL SEATBACK FAILURES AT THE HINGE POINT OR AT THE WELDED JUNCTION OF THE SEAT'S LOWER SIDE TUBE & SEATBACK SIDE BRACE.

## Aircraft

- Registration: [N50702](https://openairdocs.org/deregistered/N50702-2013-03-21), registration cancelled 2013-03-21, S/N 616-80 (OpenAirDocs)
- Reported make and model: BELLANCA 8KCAB
- Registry model: [Bellanca 8KCAB](https://openairdocs.org/model/bellanca-8kcab) (registry code 1220801) (OpenAirDocs)
- Registry engine: [NONE](https://openairdocs.org/engine/none) (registry code 00000, none) (OpenAirDocs)
- Category: Airplane
- Serial number: 616-80
- Airframe hours: 1343
- Engines: LYCOMING AEIO-360-H1A 180 horsepower reciprocating
- Damage: Destroyed
- Flight: Personal, Part 91
- Operator: Lewis, Richard A.
- Registered owner: Lewis, Richard A
- Airworthiness certificate: Standard, Normal; Standard, Aerobatic
- Last inspection: Annual, April 29, 1988, 117 hours before
- Departed: 1C5, PLAINFIELD, IL

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 52; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, valid medical--w/ waivers/lim; seat: front; toxicology performed; flight hours: 1,312 total, 333 in this make and model, 55 in the last 90 days, 22 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 300° at 10 knots
- Visibility: 15 statute miles
- Lowest ceiling: none
- Temperature: 63 °F, dew point 52 °F
- Altimeter: 29.00 inHg
- Observed at: DPA, 14 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 (OpenAirDocs).

- [Accident 19880920039529A](https://openairdocs.org/incident/19880920039529A), Sep 20, 1988: Bbavia 8KCAB, Oswego, IL, Destroyed, 1 fatal. During acrobatic practice, nosed up abruptly and right wing separated. Seat back had also failed.

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

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