# NTSB LAX91LA260: Piper PA-22-135, N1429C, Sonita, AZ, June 16, 1991

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: June 16, 1991, 13:00 local (20:00 UTC)
- Place: Sonita, AZ
- Coordinates: 31.749568, -110.659126 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=31.7496&lon=-110.6591&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report May 7, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 27247
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX91LA260
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/27247/pdf
- Page: https://openairdocs.org/ntsb/LAX91LA260

## Probable cause

A LOSS OF ENGINE POWER DUE TO A BROKEN PISTON RING IN THE NUMBER 3 CYLINDER, WHICH RESULTED IN THE AIRCRAFT'S INABILITY TO MAINTAIN LEVEL FLIGHT.

## Sequence of events

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

- Loss of engine power, cruise - normal
  - engine assembly - failure,partial (cause)
  - engine assembly,ring - cracked (cause)
- Forced landing, descent - emergency
- Nose over, landing - roll
  - terrain condition - ditch

## Analysis

DURING CRUISE FLIGHT, THE AIRPLANE'S ENGINE BEGAN TO RUN ROUGH.  THE PILOT EXECUTED EMERGENCY PROCEDURES TO TRY TO REGAIN ADEQUATE POWER.  THE POWER WAS NOT RESTORED AND THE AIRCRAFT COULD NOT MAINTAIN LEVEL FLIGHT.  THE PILOT EXECUTED A FORCED LANDING TO A FIELD.  DURING THE LANDING ROLL, THE AIRCRAFT COLLIDED WITH A DITCH, TRAVELED ABOUT 20 YARDS, AND NOSED OVER. EXAMINATION OF THE AIRCRAFT'S ENGINE REVEALED THAT A PISTON RING IN THE NUMBER 3 CYLINDER WAS BROKEN WHICH ALLOWED BLOW BY IN THE CYLINDER. THE PILOT SAID THAT HE HAD VAPOR LOCK.  HE TOLD AN FAA SAFETY INSPECTOR THAT HE HAD USED AUTOMOBILE GAS FOR THE FLIGHT AND THE GAS WAS TRANSPORTED USING 'OLD CANS' FROM HIS FATHER'S HOUSE. NO EVIDENCE WAS FOUND TO INDICATE THAT THE AIRCRAFT'S ENGINE HAD VAPOR LOCK.

## Aircraft

- Registration: [N1429C](https://openairdocs.org/aircraft/N1429C), registered now, S/N 22-1183, built 1953 (OpenAirDocs)
- Reported make and model: PIPER PA-22-135
- Registry model: [Piper PA-22-135](https://openairdocs.org/model/piper-pa-22-135) (registry code 7102206) (OpenAirDocs)
- Registry engine: [Lycoming 0-290 series](https://openairdocs.org/engine/lycoming-0-290-series) (registry code 41506, 4 cycle) (OpenAirDocs)
- Category: Airplane
- Serial number: 22-1183
- Engines: LYCOMING O-290-D2 135 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Dennis Kt. Kirby/John C Davis
- Registered owner: Dennis Kt. Kirby/John C Davis
- Last inspection: Unknown, January 2, 2000
- Departed: RYN, TUCSON, AZ
- Destination: FHU, FT. HUACHUCA, AZ
- Flight plan: VFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 30; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, valid medical--w/ waivers/lim; flight hours: 368 total, 19 in this make and model, 340 as pilot in command, 18 in the last 90 days, 6 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Visibility: 60 statute miles
- Lowest ceiling: none
- Temperature: 104 °F

## 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 19910616021909A](https://openairdocs.org/incident/19910616021909A), Jun 16, 1991: Piper PA22135, Sonoita, AZ, Substantial damage. Low power en route precipitated landing. Struck a ditch. Nosed over. Found broken piston ring NR3 cylinder.

## Other investigations on N1429C (1)

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.

- [NTSB FTW69F0224](https://openairdocs.org/ntsb/FTW69F0224), Oct 1, 1968: Piper PA-22 (N1429C), Yukon, OK, substantial damage

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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