# NTSB SEA92LA171: Boeing B-75, N5176N, Three Forks, MT, August 1, 1992

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: August 1, 1992, 12:10 local (18:10 UTC)
- Place: Three Forks, MT
- Coordinates: 45.910068, -111.429527 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=45.9101&lon=-111.4295&mi=10
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report August 31, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 42868
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA92LA171
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/42868/pdf
- Page: https://openairdocs.org/ntsb/SEA92LA171

## Probable cause

THE PILOT'S FAILURE TO MAINTAIN DIRECTIONAL CONTROL. FACTORS INCLUDE A CROSSWIND GUST.

## Sequence of events

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

- Nose over, landing - roll
  - directional control - not maintained, pilot in command (cause)
  - weather condition - crosswind (contributing factor)
  - weather condition - gusts (contributing factor)

## Analysis

THE STUDENT PILOT FAILED TO MAINTAIN AIRCRAFT CONTROL WHEN HIS BOEING B-75 ENCOUNTERED A CROSSWIND GUST JUST AFTER TOUCHDOWN. THE PILOT ATTEMPTED A RECOVERY USING DIFFERENTIAL BRAKING AND RUDDER APPLICATION, BUT THE AIRCRAFT FLIPPED-OVER NEAR THE LEFT EDGE OF THE RUNWAY.

## Aircraft

- Registration: [N5176N](https://openairdocs.org/aircraft/N5176N), registered now, S/N 75-5379 (OpenAirDocs)
- Reported make and model: BOEING B-75
- Registry model: [Boeing E75](https://openairdocs.org/model/boeing-e75) (registry code 1380120) (OpenAirDocs)
- Registry engine: [Lycoming R680](https://openairdocs.org/engine/lycoming-r680) (registry code 41540, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 75-5379
- Airframe hours: 3258
- Engines: LYCOMING R-680-B4D 225 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Martin, Brooks & Jenny
- Registered owner: Martin, Brooks & Jenny
- Airworthiness certificate: Standard, Aerobatic
- Last inspection: Annual, July 30, 1992, 8 hours before
- Departed: BZN, BOZEMAN, MT
- Airport: 9S5, Three Forks Airport, runway 2, 4,100 × 60 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 40; student; medical: class 3, valid medical--w/ waivers/lim; seat: rear; flight hours: 221 total, 82 in this make and model, 127 as pilot in command, 32 in the last 90 days, 11 in the last 30 days, 2 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 20° at 5 knots
- Visibility: 30 statute miles
- Lowest ceiling: none
- Temperature: 84 °F, dew point 46 °F
- Altimeter: 30.00 inHg

## 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 19920801028489A](https://openairdocs.org/incident/19920801028489A), Aug 1, 1992: Boeing E75, Three Forks, MT, Substantial damage. Gust caused aircraft to swerve on landing roll. Student tried to compensate by rudder and brakes. Nosed over.

## Other investigations on N5176N (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 WPR13CA325](https://openairdocs.org/ntsb/WPR13CA325), Jul 14, 2013: Boeing E75 (N5176N), Bozeman, MT, substantial damage. Probable cause: The pilot’s failure to maintain adequate airspeed during a turn, which resulted in a loss of lift and collision with terrain.

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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