Beechcraft A36 N3103W

Summary

On 23 February 1998 at about 19:00 local time, a Beechcraft A36 registered N3103W, operated by Howard R. Burchill, was involved in an accident near San Gorgonio Mo, California, United States. 2 people were on board and 2 died. The aircraft was destroyed. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

23 February 1998 at 19:00

Classification

Accident

Location

San Gorgonio Mo, California, United States

Nearest airport

Big Bear (L35)

Coordinates

34.0800, -116.9008

Aircraft

Beechcraft A36

Registration

N3103W

Category

Airplane

Engines

1

Operator

Howard R. Burchill

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Big Bear City → Carlsbad

Aircraft damage

Destroyed

Weather

VMC

Light

Day

NTSB number

LAX98FA095

2 people died.

The pilot's inability to maintain altitude due to an encounter with adverse winds and downdrafts on the lee side of a mountain. Also causal was the pilot's inadequate weather evaluation, which precipitated his intentional flight into an area of known adverse weather in high mountainous terrain. Factors include terrain induced turbulence and downdrafts as a result of high wind conditions.

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

Read the full NTSB narrative

The airplane collided with mountainous terrain about 11.3 nautical miles south-southeast of the departure airport. The departure airport's automated weather observation system was reporting skies clear to 12,000 feet above ground level (agl), with winds from 220 degrees at 14 knots gusting to 26 knots at the estimated time of departure. The pilot received a weather briefing 1 hour 46 minutes prior to departure. He was informed that the winds at 9,000 feet mean sea level (msl) over the area were 210 degrees at 50 knots, and that conditions would get worse by 1100. The briefing also contained AIRMETS for mountain obscuration, moderate turbulence, and moderate rime and mixed icing above the freezing level. The accident site elevation was approximately 10,300 feet msl. The airplane approached the accident site on a heading of approximately 240 degrees. This would have placed the airplane on the lee side of a high ridgeline with winds exceeding 50 knots. There was a valley extending towards the southwest directly in front of and 90 degrees to the ridgeline on which the airplane crashed. This valley may have produced a funneling effect, which would have significantly accelerated the wind flow over the ridge. Satellite imagery of the site at the time of the accident showed high clouds above the mountains. The cloud tops were estimated to be 13,000 feet. Additionally, rotor clouds could be seen southwest of the crash site. Studies have shown that severe turbulence, wind shear, and downdrafts are commonly found on the downwind side of high mountainous terrain when high wind conditions exist. The maximum climb rate for the airplane at 9,000 feet under static conditions was calculated to be 900 feet per minute. No preimpact mechanical malfunctions were found during examination of the wreckage.

Quoted verbatim from the NTSB record.