# NTSB CHI83FA370: Zenair Cricket MC12, Oshkosh, WI, August 5, 1983

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Field investigation · Final report
- Date: August 5, 1983, 15:45 local (20:45 UTC)
- Place: Oshkosh, WI
- Coordinates: 44.060626, -88.540618 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=44.0606&lon=-88.5406&mi=10
- Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 1 minor
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 12015
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI83FA370
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/12015/pdf
- Page: https://openairdocs.org/ntsb/CHI83FA370

## Sequence of events

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

- Loss of engine power(partial) - mech failure/malf, takeoff - initial climb
  - ignition system,spark plug - disabled (cause)
- Loss of control - in flight, takeoff
  - airspeed(vmc) - not maintained, pilot in command (cause)
  - stall - inadvertent, pilot in command (cause)
- In flight collision with terrain/water, descent - uncontrolled

## Analysis

DURING A FORMATION TAKEOFF, THE PLT WAS FLYING IN A LEFT WINGMAN POSITION & THE FLT ENTERED A RELATIVELY STEEP CLIMB. THE PLT STATED THAT THE AIRSPEED WAS SLIGHTLY ABOVE THE STALL SPEED AT ABOUT 100 TO 150 FT AGL WHEN THE LEFT ENG LOST POWER & THE ACFT BEGAN TURNING LEFT & LOSING ALT. HE REPORTED THAT THE PLANE STALLED & HE COULD NOT CONTROL THE LEFT YAW & TURN, UNTIL AFTER HE LOWERED THE NOSE & REGAINED AIRSPEED. HE DID NOT REDUCE POWER ON THE OPERATING ENG. SUBSEQUENTLY, THE ACFT STRUCK THE GROUND IN A SLIGHT NOSE DOWN ATTITUDE. AN INVESTIGATON REVEALED THAT THE SINGLE SPARK PLUG IN THE LEFT, SINGLE CYLINDER, 2 STROKE ENG WAS NOT FIRING AT THE ELECTRODE TIP.

## Aircraft

- Registration: CGAYW (not matched to a registry record)
- Reported make and model: ZENAIR CRICKET MC12 (CRICKET MC)
- Category: Airplane, amateur-built
- Engines: JPX POL reciprocating
- Damage: Substantial damage
- Flight: Part 91
- Registered owner: Zenair Corp
- Airworthiness certificate: Special, Experimental (Special)
- Last inspection: Annual, August 1, 1985, 10 hours before
- Airport: OSH, Wittman Field, runway 36, 6,700 × 150 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 53; private; airplane ratings: multi-engine land, single-engine land; medical: class 3, valid medical--no waivers/lim.; seat: front; flight hours: 9,000 total, 125 in this make and model, 100 in the last 90 days

## Weather

- Conditions: Visual (VMC), Day
- Visibility: 15 statute miles
- Lowest ceiling: none
- Temperature: 91 °F

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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