# NTSB SEA89LA133: Aeronca 7AC, N1636E, American Falls, ID, July 16, 1989

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: July 15, 1989, 19:40 local (Jul 16, 1989, 01:40 UTC)
- Place: American Falls, ID
- Coordinates: 42.720447, -112.990936 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=42.7204&lon=-112.9909&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report January 23, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 41048
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA89LA133
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/41048/pdf
- Page: https://openairdocs.org/ntsb/SEA89LA133

## Probable cause

AN ENGINE FAILURE DUE TO STRIPPED AND BROKEN TEETH ON A MAGNETO DRIVE GEAR IN THE ACCESSORY GEAR BOX. A SOFT FIELD CAUSED THE NOSE OVER DURING THE FORCED LANDING.

## 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, cruise - normal
  - accessory drive assy,drive gear - failure,partial (cause)
- Forced landing, landing - flare/touchdown
- Nose over, landing - roll
  - terrain condition - soft (contributing factor)

## Analysis

THE PLT RPRTD THAT DURING FLT THE ENG LOST POWER. SUBSEQUENTLY,THE ACFT NOSED OVER DURING AN EMERGENCY LANDING IN A SOFT FIELD. RPRTDLY, AN ACCESSORY GEAR THAT DROVE A MAGNETO HAD BECOME STRIPPED AND BROKEN, CAUSING THE MAGNETO TO GET OUT OF TIME WITH THE CAM.

## Aircraft

- Registration: [N1636E](https://openairdocs.org/aircraft/N1636E), registered now, S/N 7AC5201 (OpenAirDocs)
- Reported make and model: AERONCA 7AC
- Registry model: [Aeronca 7AC](https://openairdocs.org/model/aeronca-7ac) (registry code 2110102) (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: 7AC5201
- Engines: CONTINENTAL C-65-8 65 horsepower reciprocating
- Damage: Substantial damage
- Flight: Business, Part 91
- Operator: Roger Nelson
- Registered owner: Roger Nelson
- Airworthiness certificate: Standard, Normal
- Departed: JEROME, ID
- Destination: AMERICAN FALLS, ID

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 45; medical: unknown, unknown; seat: front

## Weather

- Conditions: Visual (VMC), Day
- Wind: 350° at 5 knots
- Visibility: 40 statute miles
- Lowest ceiling: 10,000 ft overcast
- Temperature: 70 °F, dew point 52 °F
- Altimeter: 30.00 inHg
- Observed at: IDA, 70 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 19890715066149A](https://openairdocs.org/incident/19890715066149A), Jul 15, 1989: Bbavia 7AC, American Falls, ID, Substantial damage. Lost power en route. Nosed over landing. Magneto drive gear stripped its teeth causing magneto to get out of timing

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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