# NTSB MKC87LA115: Ayres S2R600, N4943X, Lepanto, AR, June 2, 1987

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: June 2, 1987, 08:00 local (13:00 UTC)
- Place: Lepanto, AR
- Coordinates: 35.599079, -90.329856 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=35.5991&lon=-90.3299&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report May 9, 1988
- Report: Approved by Office Director
- NTSB case key (mKey): 34392
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=MKC87LA115
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/34392/pdf
- Page: https://openairdocs.org/ntsb/MKC87LA115

## 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, cruise
  - engine assembly,rocker arm/tappet - cracked (cause)
  - engine assembly,valve,intake - jammed (contributing factor)
- Forced landing, cruise
- Nose over, landing - roll
  - terrain condition - soft (cause)

## Analysis

THE PIC HAD TAKEN OFF FOR A LCL AERIAL OPERATION. ENROUTE PIC HAD AN ENGINE FAILURE AND MADE A FORCED LDG IN A MUDDY FIELD. PIC APPLIED BRAKES AND ACFT NOSED OVER. THE EXHAUST ROCKER ARM BOX ON NO. 3 CYLINDER WAS FOUND TO BE CRACKED KEEPING EXHAUST VALVE IN CLOSED POSITION.

## Aircraft

- Registration: [N4943X](https://openairdocs.org/deregistered/N4943X-1996-05-13), registration cancelled 1996-05-13, S/N 5004R (OpenAirDocs)
- Reported make and model: Ayres S2R600
- Registry model: [Rockwell International S-2R](https://openairdocs.org/model/rockwell-international-s-2r) (registry code 7630202) (OpenAirDocs)
- Category: Airplane
- Serial number: 5004R
- Airframe hours: 2267
- Engines: P&W R-1340-AN1 600 horsepower reciprocating
- Damage: Substantial damage
- Flight: Aerial application, Part 137
- Registered owner: Helm Flying Service
- Airworthiness certificate: Special, Restricted (Special)

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 34; commercial; airplane ratings: multi-engine land, single-engine land; medical: class 2, valid medical--no waivers/lim.; seat: center; flight hours: 6,000 total, 2,000 in this make and model, 6,000 as pilot in command, 100 in the last 90 days, 100 in the last 30 days, 6 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 180° at 7 knots
- Lowest ceiling: none
- Temperature: -0 °F, dew point -0 °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 19870602021229A](https://openairdocs.org/incident/19870602021229A), Jun 2, 1987: Ayres S2RRESTD, Lepanto, AR, Substantial damage. The engine failed from a cracked rocker box which held the exhast valve closed. Landing used brakes and nosed over.

## Other investigations on N4943X (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 MKC89DPG04](https://openairdocs.org/ntsb/MKC89DPG04), Aug 6, 1989: Rockwell S-2R (N4943X), Moscow, AR, destroyed. Probable cause: INADEQUATE VISUAL LOOKOUT BY THE PILOT. THE GUY WIRE WAS A CONTRIBUTING 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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