Boeing A75L3 N53466

Summary

On 6 September 2024 at about 19:59 local time, a Boeing A75L3 registered N53466 was involved in an accident near Yacolt, Washington, United States. 2 people were on board and one died, one was seriously injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

6 September 2024 at 19:59

Classification

Accident

Location

Yacolt, Washington, United States

Coordinates

45.7829, -122.1731

Aircraft

Boeing A75L3

Registration

N53466

Category

Airplane

Year built

1941

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Toledo → Hood River

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

WPR24FA298

1 person died.

The pilot’s exceedance of the airplane’s critical angle of attack while maneuvering at a low altitude in mountainous terrain in moderately high density altitude conditions, resulting in an aerodynamic stall and subsequent impact with terrain.

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

Read the full NTSB narrative

The accident airplane was one of three airplanes traveling together on a cross-country flight. The pilots of the accident airplane and one of the other two airplanes chose to divert from the group’s typical route of flight to fly an alternate route through rising, mountainous terrain. As the two airplanes approached an area of higher terrain and a ridgeline that required a climb, the pilot of the second airplane flying the alternate route initiated a circling climb to gain sufficient altitude needed to cross the approaching ridgeline. He then continued on toward the intended destination, unaware that the accident airplane was not behind his airplane. When approaching the same ridgeline, the pilot of the accident airplane maintained an altitude that was lower than the elevation of the ridgeline and did not initiate a climb. The airplane maintained an altitude of about 2,900 ft mean sea level (msl) until it entered a left turn, followed by a rapid descent above the accident location. The airplane’s ground speed had slowed to 40 kts at the onset of the rapid descent and the left turn began about .63 statute miles from terrain that rose to 3,550 ft msl, which was the lowest available terrain ahead of the airplane’s position. The pilot likely initiated a left turn away from rising terrain and exceeded the airplane’s critical angle of attack. The investigation was unable to determine why the pilot did not initiate a climb earlier in the flight. The pilot of the second airplane flying the alternate route reported that “it wasn’t too smooth out,” which was consistent with terrain-induced wind and/or turbulence. He reported that at the initiation of his climb he added engine power, saw his ground speed decrease and then added additional engine power. He subsequently chose to circle climb to clear the ridgeline. The calculated density altitude near the accident site was 4,626 ft. Postaccident examination of the engine and airframe revealed no evidence of preaccident malfunction or failure.

Quoted verbatim from the NTSB record.