# NTSB DEN89IA028: Beech S-35, N977KM, Matheson, CO, November 3, 1988

- Type: NTSB incident investigation
- Classification: Incident · No injuries · Incident investigation · Final report
- Date: November 3, 1988, 14:00 local (21:00 UTC)
- Place: Matheson, CO
- Coordinates: 39.110771, -103.89019 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=39.1108&lon=-103.8902&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report June 11, 1990
- Report: Approved by Office Director
- NTSB case key (mKey): 17612
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN89IA028
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/17612/pdf
- Page: https://openairdocs.org/ntsb/DEN89IA028

## Sequence of events

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

- Airframe/component/system failure/malfunction, cruise - normal
  - propeller system/accessories,hub - separation (cause)
  - maintenance,major alteration - not performed, other maintenance personnel (cause)
  - engine assembly - seized
  - maintenance,modification - information insufficient, other maintenance personnel (contributing factor)
- Forced landing, descent - emergency
- Gear not extended, landing - flare/touchdown
  - terrain condition - crop

## Analysis

THE PRIVATE PLT AND A FRIEND WERE ENROUTE FOR A HUNTING TRIP. THIRTY MILES EAST OF A REFUELING STOP, THE PILOT HEARD A LOUD KNOCK. OIL COVERED THE WINDSCREEN AND THE ENGINE SEIZED. THE PLT LOOKED OUT THE SIDE WINDOW VENT TO SELECT A FORCED LANDING AREA. A WHEELS UP LANDING WAS PERFORMED IN A GRAIN FIELD. AFTER EXITING THE ACFT, THE PLT SAW THAT THE PROPELLER WAS MISSING. DAMAGE WAS REPORTED AS SUBSTANTIAL, BUT A POST INCIDENT INSPECTION REVEALED MINOR DAMAGE. THE PROPELLER WAS NOT FOUND BUT TWO SHEARED PROPELLER BOLTS, P/N A-2040 WERE FOUND IN THE COWLING. IN A PHONE CONVERSATION, A HARTZELL TECHNICAL REPRESENTATIVE, SAID THE PROPER BOLT FOR THIS INSTALLATION IS P/N A-1328-1. HE SAID P/N A-2040 WAS SUPERSEDED PRIOR TO 1970. LOG BOOKS SHOW THIS PROPELLER WAS OVERHAULED 83 FLIGHT HRS PRIOR TO THIS INCIDENT. THE REPAIR SHOP REPORTED THAT THE BOLTS THEY REMOVED WERE INSPECTED AND RE-INSTALLED IN THE HUB.

## Aircraft

- Registration: [N977KM](https://openairdocs.org/aircraft/N977KM), registered now, S/N D-7366, built 1964 (OpenAirDocs)
- Reported make and model: BEECH S-35
- Registry model: [Beech S35](https://openairdocs.org/model/beech-s35) (registry code 1151532) (OpenAirDocs)
- Registry engine: [Continental IO-520 series](https://openairdocs.org/engine/continental-io-520-series) (registry code 17032, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: D 7366
- Airframe hours: 2905
- Engines: CONTINENTAL IO-520-BA 285 horsepower reciprocating
- Damage: Minor damage
- Flight: Personal, Part 91
- Registered owner: Grant B. Kelley
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, August 8, 1988, 130 hours before
- Departed: MKC, KANSAS CITY, MO
- Destination: OOV, FALCON, CO

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 28; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, valid medical--no waivers/lim.; seat: left; flight hours: 433 total, 373 in this make and model, 399 as pilot in command, 96 in the last 90 days, 44 in the last 30 days, 6 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 360° at 15 knots
- Visibility: 20 statute miles

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Incident 19881103051239I](https://openairdocs.org/incident/19881103051239I), Nov 3, 1988: Beech S35, Matheson, CO, Minor damage. Lost power and oil pressure. Oil on windshield. Engine seized. Landed gear up. Propeller assembly bolts sheared.

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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