On August 9, 1982, a Piper PA-20 (registration N1970A) operated by Albin I. Reynolds was involved in an aviation accident near Scottsbluff, NE. Investigators recorded the probable cause as: The left brake's master cylinder compensating port was plugged with dirt, which bound the left brake and prevented the left wheel from rotating freely. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
During takeoff, a pilot raised the tail at about 50 mph, causing the aircraft to veer left and depart the runway. The right gear collapsed, damaging the right wing and propeller. Investigation revealed the left brake was binding due to a dirt-clogged master cylinder compensating port.
Accident Overview
During the takeoff roll, the pilot raised the aircraft's tail at approximately 50 miles per hour. Immediately afterward, the aircraft began to veer to the left. Despite the pilot's corrective inputs, the aircraft continued left of the runway centerline and departed the left side of the runway.
Damage Sequence
After departing the runway surface, the right landing gear collapsed. The right wing and propeller sustained damage during the event.
Post-Accident Investigation
An inspection of the left brake system revealed that the compensating port on the master cylinder was plugged with dirt. This obstruction caused the left brake to bind excessively, to the extent that the left wheel assembly would barely rotate.
Probable cause
The left brake's master cylinder compensating port was plugged with dirt, which bound the left brake and prevented the left wheel from rotating freely.