# NTSB SEA01LA011: Cessna 172, Conconully, WA, October 30, 2000

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Limited investigation · Final report
- Date: October 30, 2000, 08:00 local (16:00 UTC)
- Place: Conconully, WA
- Coordinates: 48.560207, -119.350128 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=48.5602&lon=-119.3501&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 2 minor
- Status: Completed, report September 6, 2001
- Report: Approved by Office Director
- NTSB case key (mKey): 51342
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA01LA011
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/51342/pdf
- Page: https://openairdocs.org/ntsb/SEA01LA011

## Probable cause

The pilot's failure to maintain clearance from the trees while flying at a very low altitude in mountainous/hilly terrain. Factors include, forested mountainous/hilly terrain, flight at a very low altitude, and an encounter with a downdraft.

## Sequence of events

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

- In flight collision with object, maneuvering
  - clearance - not maintained, pilot in command (cause)
  - altitude - low, pilot in command (contributing factor)
  - weather condition - downdraft (contributing factor)
  - object - tree(s) (contributing factor)
  - terrain condition - mountainous/hilly (contributing factor)

## Analysis

While flying very low over forested mountainous terrain, the aircraft encountered a downdraft that caused it to suddenly sink. Before the pilot was able to take corrective action, one of the aircraft's wings collided with a tree, and it cart wheeled into the terrain. After the aircraft came to rest, a fire erupted that consumed about 50 percent of the aircraft structure.

## Factual narrative

On October 30, 2000, approximately 0800 Pacific standard time, a Canadian-registered Cessna 172, C-GDNN, collided with a tree during low-level maneuvering about 7 miles northeast of Conconully, Washington. The pilot, who held a Canadian private pilot's license, and his passenger both received minor injuries. The aircraft, which was owned and operated by the pilot, was destroyed by a post-impact fire. The 14 CFR Part 91 personal pleasure flight, which departed Princeton Airport, Princeton, British Columbia, Canada, about 45 minutes earlier, was operating in visual meteorological conditions. No flight plan had been filed. There was no report of an ELT activation.

According to the pilot, who did not return the NTSB Form 6120.1/2, he took off for a local sightseeing flight, and once airborne decided to cross the United States/Canadian border in order to show his passenger some of the terrain in northern Washington. He said that at the time of the accident, he was heading back toward Canada while flying very low over the trees. Reportedly, he encountered a downdraft, which made the aircraft suddenly sink. According to the pilot, before he could take corrective action, one wing collided with a tree, and the aircraft cart wheeled into the forest. After coming to rest, it caught fire. The pilot and his passenger were able to exit the aircraft, but approximately 50 percent of the aircraft structure was consumed by the fire.

## Aircraft

- Registration: CGDNN (not matched to a registry record)
- Reported make and model: Cessna 172
- Category: Airplane
- Serial number: 29068
- Engines: Continental O-300A 145 horsepower reciprocating
- Damage: Destroyed
- Fire: On-Ground
- Flight: Personal, Part 91
- Registered owner: Gordon Simpson
- Airworthiness certificate: Standard, Normal
- Departed: YDC, PRINCETON

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; private; airplane ratings: single-engine land; medical: unknown, unknown; seat: left

## Weather

- Conditions: Visual (VMC), Day
- Wind: variable at 5 knots
- Visibility: 20 statute miles
- Lowest ceiling: none
- Temperature: 102 °F, dew point 99 °F

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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