# NTSB SEA91LA206: Beech V35B, N18307, Belgrade, MT, August 12, 1991

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: August 11, 1991, 18:10 local (Aug 12, 1991, 00:10 UTC)
- Place: Belgrade, MT
- Coordinates: 45.810527, -111.150062 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=45.8105&lon=-111.1501&mi=10
- Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 4 uninjured
- Status: Completed, report March 9, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 41511
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA91LA206
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/41511/pdf
- Page: https://openairdocs.org/ntsb/SEA91LA206

## Probable cause

THE PILOT'S FAILURE TO MAINTAIN A POSITIVE RATE OF CLIMB DURING THE TAKEOFF.  FACTORS CONTRIBUTING TO THE ACCIDENT WERE THE OPEN CABIN WINDOW AND THE PILOT'S DIVERTING HIS ATTENTION.

## Sequence of events

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

- In flight collision with terrain/water, takeoff
  - window,cabin - open (contributing factor)
  - proper climb rate - not maintained, pilot in command (cause)
  - diverted attention, pilot in command (contributing factor)

## Analysis

IMMEDIATELY FOLLOWING GEAR RETRACTION ON TAKEOFF THE RIGHT CENTER CABIN WINDOW OPENED.  THE PILOT'S ATTENTION WAS DIVERTED BY THE AMBIENT NOISE AND ITS EFFECT ON HIS DAUGHTER WHO WAS SEATED ADJACENT TO THE WINDOW.  THE PILOT THEN TURNED HIS ATTENTION TO SECURING THE WINDOW AND DURING THIS EVENT FAILED TO MAINTAIN A POSITIVE CLIMB RATE.  THE AIRCRAFT THEN SETTLED BACK TO THE RUNWAY.

## Aircraft

- Registration: [N18307](https://openairdocs.org/aircraft/N18307), registered now, S/N D-10038, built 1977 (OpenAirDocs)
- Reported make and model: BEECH V35B
- Registry model: [Beech V35B](https://openairdocs.org/model/beech-v35b) (registry code 1151548) (OpenAirDocs)
- Registry engine: [Continental IO-520 series](https://openairdocs.org/engine/continental-io-520-series) (registry code 17032, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: D10038
- Engines: CONTINENTAL IO-520 285 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Mm&O Aviation, Inc.
- Registered owner: Mm&O Aviation, Inc.
- Destination: BJC, DENVER, CO
- Airport: BZN, Gallatin Field, runway 3, 9,003 × 150 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 45; commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; flight hours: 5,911 total, 4,000 in this make and model, 5,380 as pilot in command, 85 in the last 90 days, 45 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 320° at 4 knots
- Visibility: 30 statute miles
- Lowest ceiling: none
- Temperature: 91 °F, dew point 39 °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 19910811036929A](https://openairdocs.org/incident/19910811036929A), Aug 11, 1991: Beech V35B, Bozeman, MT, Substantial damage. Rear emergency window opened on liftoff. Tried to close. Aborted but gear in transit collapsed on touchdown.

## Other investigations on N18307 (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 MKC89LA118](https://openairdocs.org/ntsb/MKC89LA118), May 27, 1989: Beech V35 (N18307), Strong, AR, substantial damage. Probable cause: ENGINE FAILURE DUE TO FUEL STARVATION.

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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