# NTSB ATL91LA113: Rockwell S-2R, N8549V, Camilla, GA, June 17, 1991

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: June 17, 1991, 08:30 local (12:30 UTC)
- Place: Camilla, GA
- Coordinates: 31.220623, -84.210243 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=31.2206&lon=-84.2102&mi=10
- Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report March 31, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 8421
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ATL91LA113
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/8421/pdf
- Page: https://openairdocs.org/ntsb/ATL91LA113

## Probable cause

RESTRICTED EXHAUST VALVE MOVEMENT, LOW CYLINDER COMPRESSION, AND FOULING OF THE ENGINE SPARK PLUGS, WHICH RESULTED IN THE LOSS OF ENGINE POWER. FACTORS WERE THE IMPROPER SERVICING OF THE AIRCRAFT, AND THE USE OF AN IMPROPER FUEL GRADE.

## Sequence of events

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

- Loss of engine power(total) - mech failure/malf, takeoff - initial climb
  - maintenance,service of aircraft/equipment - improper, company/operator management (contributing factor)
  - fluid,fuel grade - improper (contributing factor)
  - engine assembly,valve,exhaust - movement restricted (cause)
  - engine assembly,cylinder - low compression (cause)
  - ignition system,spark plug - fouled (cause)
- Forced landing, descent - emergency
- In flight collision with terrain/water, descent - emergency
  - object - tree(s)

## Analysis

THE PILOT REPORTED THAT SHORTLY AFTER TAKEOFF, THE ENGINE SHUDDERED VIOLENTLY, THEN QUIT. THE AIRPLANE WAS FORCE LANDED STRAIGHT AHEAD, AND WAS SUBSTANTIALLY DAMAGED BY THE ENSUING COLLISION WITH TREES. POST-CRASH INSPECTION OF THE ENGINE REVEALED THAT THE SPARK PLUGS WERE BADLY CARBON FOULED. NO COMPRESSION WAS OBSERVED ON THE NUMBER ONE CYLINDER, AND COMPRESSION ON THE REMAINING CYLINDERS WAS ONLY 'FAIR.' DISASSEMBLY OF THE NUMBER ONE CYLINDER REVEALED THAT THE EXHAUST VALVE AND SEAT WERE PARTIALLY BURNED. A HAMMER WAS REQUIRED TO REMOVE THE VALVE FROM THE CYLINDER. THE PISTON WAS BADLY CARBONED. A MECHANIC REPORTED THAT THE OPERATOR WAS USING AUTOMOTIVE GASOLINE IN THIS AIRPLANE, WITHOUT AN STC FOR ITS USE.

## Aircraft

- Registration: [N8549V](https://openairdocs.org/aircraft/N8549V), registered now, S/N 2309R (OpenAirDocs)
- Reported make and model: Rockwell S-2R
- Registry model: [Rockwell International S-2R](https://openairdocs.org/model/rockwell-international-s-2r) (registry code 7630202) (OpenAirDocs)
- Category: Airplane
- Serial number: 2309
- Airframe hours: 4464
- Engines: P&W R-1340-AN1 550 horsepower reciprocating
- Damage: Substantial damage
- Flight: Aerial application, Part 137
- Operator: Maxwell Aviation, Inc.
- Registered owner: Maxwell Aviation, Inc.
- Last inspection: Annual, July 18, 1990, 273 hours before
- Airport: CXU, Mitchell County, runway 8, 4,005 × 60 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 57; commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: helicopter; medical: class 2, unknown; flight hours: 12,000 total, 5,000 in this make and model

## Weather

- Conditions: Visual (VMC), Day
- Wind: 220° at 4 knots
- Visibility: 6 statute miles
- Lowest ceiling: none
- Temperature: 73 °F, dew point 70 °F
- Altimeter: 29.00 inHg
- Observed at: ABY, 20 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 19910617022189A](https://openairdocs.org/incident/19910617022189A), Jun 17, 1991: Ayres S2RR1340REST, Camilla, GA, Substantial damage. Engine quit on takeoff. Using auto gas no STC. Stuck valve. Unleaded gas a factor. High humidity temperature factor

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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