# NTSB CHI84AA016: Kemmeyer Sonerai II, N22SK, Battle Creek, MI, October 9, 1983

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Final report
- Date: October 9, 1983, 11:47 local (15:47 UTC)
- Place: Battle Creek, MI
- Coordinates: 42.530677, -83.149124 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=42.5307&lon=-83.1491&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 1 fatal
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 12369
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI84AA016
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/12369/pdf
- Page: https://openairdocs.org/ntsb/CHI84AA016

## Sequence of events

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

- Airframe/component/system failure/malfunction, maneuvering
  - maneuver - performed, pilot in command
  - pull-up - initiated, pilot in command
  - wing,spar - overload (contributing factor)
  - design stress limits of aircraft - exceeded, pilot in command (cause)
  - wing,spar - buckled (contributing factor)
- In flight collision with terrain/water, descent - uncontrolled

## Analysis

THE PLT FLEW THE HOME BUILT ACFT FROM BATTLE CREEK TO MARSHALL, MI TO TALK TO FRIENDS. AFTER ABOUT 30 MIN, HE TOOK OFF WITHOUT REFUELING. SHORTLY AFTER THE ACFT DEPARTED, A WITNESS ON A GOLF COURSE HEARD THE SOUND OF THE ENG. HE LOOKED UP & SAW THE ACFT IN ABOUT A 30 DEG CLIMB. REPORTEDLY, THE ACFT CLIMBED APRX 400 TO 500 FT, TO A HEIGHT OF ABOUT 2000 TO 3000 FT, THEN THE NOSE CAME DOWN SLOWLY & THE ACFT STARTED DESCENDING. THE WITNESS OBSERVED THE ACFT CONTINUE DESCENDING UNTIL THE PLT STARTED TO PULL OUT OF THE DIVE. DURING THE PULL-OUT, THE RIGHT WING FOLDED UPWARD & SEPARATED. THE ACFT THEN WENT INTO A RAPID SPIN & CRASHED. AN EXAM OF THE WRECKAGE REVEALED THAT THE RIGHT WING HAD SEPARATED AT THE ROOT. THE SEPARATED WING HAD A CREASE STARTING AT THE LEADING EDGE WING ROOT & ANGLED OUTBOARD & REARWARD AT A 45 DEG ANGLE. AN EXAM OF THE TOP SPAR CAP SHOWED EVIDENCE OF BUCKLING PRIOR TO WING SEPARATION.A LOG SHOWED THAT THE PLT HAD PREVIOUSLY PERFORMED AEROBATIC FLT. THE ACFT WAS NOT CERTIFIED FOR AEROBATICS.

## Aircraft

- Registration: N22SK (not matched to a registry record)
- Reported make and model: KEMMEYER SONERAI II
- Category: Airplane, amateur-built
- Serial number: 00052
- Airframe hours: 91
- Engines: Volkswagen TYPE I 65 horsepower reciprocating
- Damage: Destroyed
- Flight: Personal, Part 91
- Registered owner: Thomas G. Baker
- Last inspection: Unknown, May 13, 1983, 24 hours before
- Departed: BTL, BATTLE CREEK, MI

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 36; airline transport, flight instructor; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: front; toxicology performed; flight hours: 4,397 total, 25 in this make and model, 2,440 as pilot in command, 100 in the last 90 days, 30 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 60° at 8 knots
- Visibility: 20 statute miles
- Lowest ceiling: 4,000 ft broken
- Temperature: 50 °F, dew point 39 °F
- Altimeter: 30.00 inHg
- Observed at: BTL, 8 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 19831009053409A](https://openairdocs.org/incident/19831009053409A), Oct 9, 1983: Amtrmo SONERAI2, Battle Creek, MI, Destroyed. Right wing separated in a dive from a hammerhead stall. Acrobatics were prohibited in the unmodified aircraft.

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.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.