Casualties unknown

2007-09-13: Beech A-36TC (N1811Q) — John O. Brown — Burlington, WA

Burlington, WA, US

On September 13, 2007, a Beech A-36TC (registration N1811Q) operated by John O. Brown was involved in an aviation accident near Burlington, WA. Investigators recorded the probable cause as: The pilot's failure to maintain the minimum descent altitude during an instrument approach in poor weather conditions, which resulted in a collision with a tree. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 1781061362Data APIEditorial standards

A pilot descended significantly below the minimum descent altitude while conducting an instrument approach in poor weather conditions, resulting in a collision with a tree.

What happened

The incident occurred during an instrument flight rules (IFR) approach under challenging meteorological conditions. Visibility was restricted to approximately one-quarter mile, and the cloud ceiling was reported at 100 feet above ground level. The aircraft was positioned one and one-half miles from the designated approach end of the runway when the pilot initiated a descent.

Instead of maintaining the required altitude, the pilot descended approximately 430 feet below the minimum descent altitude (MDA) established for this specific approach procedure. As the aircraft continued its unauthorized descent, the left wing struck a tree located below the final approach course. The impact resulted in significant damage to the airframe.

The investigation

Examination of the accident site and flight data revealed that the primary factor was the deviation from the published instrument approach procedure. The pilot failed to maintain the minimum safe altitude required for the phase of flight. No mechanical failures or system malfunctions were identified as contributing factors to the loss of controlled flight.

Findings

The investigation determined that the pilot's decision to descend below the minimum descent altitude without visual reference to the runway environment was the critical error. The poor weather conditions, specifically the low ceiling and limited visibility, necessitated strict adherence to instrument procedures. Failure to comply with these safety margins led directly to the collision with terrain.

Safety message

Pilots conducting instrument approaches must strictly adhere to published minimum descent altitudes until visual reference is established. Deviating below these altitudes in poor weather conditions significantly increases the risk of controlled flight into terrain (CFIT). Adherence to standard operating procedures is essential for safety during low-visibility operations.

Probable cause

The pilot's failure to maintain the minimum descent altitude during an instrument approach in poor weather conditions, which resulted in a collision with a tree.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20070924X01433. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.