Cessna 180 N66036

Summary

On 11 March 2008 at about 18:50 local time, a Cessna 180 registered N66036 was involved in an accident near White Mountain, Alaska, United States. 3 people were on board and 2 had minor injuries. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

11 March 2008 at 18:50

Classification

Accident

Location

White Mountain, Alaska, United States

Coordinates

64.7097, -162.7628

Aircraft

Cessna 180

Registration

N66036

Category

Airplane

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Koyuk → White Mountain

Aircraft damage

Substantial

Weather

IMC

Light

Day

NTSB number

ANC08LA042

2 people had minor injuries.

The pilot’s inadvertent flight into flat light/whiteout conditions over snow-covered terrain.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

The airline transport pilot was in cruise flight at 2,500 feet msl over snow-covered mountainous terrain. He said the weather conditions were reported as having a ceiling of about 3,000 feet, and a visibility of 10 miles. The route crossed an area of low hills, and the pilot said the visibility began to deteriorate. He descended to about 2,000 feet msl, and suddenly flew into whiteout conditions. The airplane collided with a mountain ridge and overturned. The airplane received structural damage to the wings, landing gear, and fuselage. A pilot who flew to the site shortly after the accident stated that he had difficulty seeing the ridge line. He stated that “visibility was good, about 5 miles, but I couldn’t make out the ridge. The ridge line was relatively horizontal, without any contrasting features, making it difficult to identify against the sky.” The Federal Aviation Administration’s Aeronautical Information Manual (AIM), Section 7-5-13, “Potential Flight Hazards, Flying in Flat Light and Whiteout Conditions,” notes that whiteout “occurs when a person becomes engulfed in a uniformly white glow…a result of being surrounded by blowing snow, dust, sand, mud or water.” The AIM states that flat light “is an optical illusion, also known as ‘sector or partial whiteout.’ Flat light conditions are usually accompanied by overcast skies inhibiting visual cues. Flat light can completely obscure features of the terrain, creating an inability to distinguish distances and closure rates.” According to the AIM, “flat light conditions can lead to a whiteout environment quite rapidly, and both atmospheric conditions are insidious; they sneak up on you as your visual references slowly begin to disappear.”

Quoted verbatim from the NTSB record.