# NTSB CHI91LA128: De Havilland Beaver U-6A, N9028, Oak Island, MN, April 9, 1991

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: April 9, 1991, 17:00 local (22:00 UTC)
- Place: Oak Island, MN
- Coordinates: 49.309356, -94.839385 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=49.3094&lon=-94.8394&mi=10
- Phase of flight: [Taxi](https://openairdocs.org/ntsb-phases/250) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 4 uninjured
- Status: Completed, report January 25, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 15039
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI91LA128
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/15039/pdf
- Page: https://openairdocs.org/ntsb/CHI91LA128

## Probable cause

UNSUITABLE TERRAIN WAS SELECTED BY THE PILOT.  A FACTOR RELATED TO THE ACCIDENT WAS THE TERRAIN/RUNWAY WAS COMPOSED OF WEAK ICE.

## Sequence of events

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

- On ground/water encounter with terrain/water, taxi - from landing
  - terrain condition - weak ice (contributing factor)
  - unsuitable terrain or takeoff/landing/taxi area - selected, pilot in command (cause)

## Analysis

THE PILOT SAID THAT WHILE TAXIING TO A BOAT DOCK, AFTER LANDING ON A FROZEN LAKE, THE RIGHT MAIN LANDING GEAR BROKE THROUGH THE ICE.  THE ACFT SUSTAINED SUBSTANTIAL DAMAGE TO THE RIGHT WING AND RIGHT WING LIFT STRUT.

## Aircraft

- Registration: N9028 (not matched to a registry record)
- Reported make and model: DE HAVILLAND BEAVER U-6A (BEAVER U-6)
- Category: Airplane
- Serial number: 803
- Engines: P&W R-985-AN1 450 horsepower reciprocating
- Damage: Substantial damage
- Flight: Part 135
- Operator: Baudette Flying Service
- Departed: BDE, BAUDETTE, MN
- Airport: Unk

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 34; flight instructor, commercial; airplane ratings: multi-engine land, single-engine sea, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; flight hours: 3,332 total, 887 in this make and model, 3,192 as pilot in command, 142 in the last 90 days, 45 in the last 30 days, 4 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 20° at 10 knots
- Visibility: 15 statute miles
- Lowest ceiling: 25,000 ft overcast
- Temperature: -0 °F, dew point -0 °F
- Observed at: INL, 80 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 19910409009529A](https://openairdocs.org/incident/19910409009529A), Apr 9, 1991: Dhav DHC1, Oak Island, MN, Substantial damage. Right main gear broke through ice taxiing to dock on frozen lake after landing.

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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