Pilot Debrief

SHANKS V ROGER VARI EZE near Santa Monica, CA — 2018-02-11

Final reportWPR18LA089
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Date
2018-02-11
Location
Santa Monica, CA, USA
Airport
SMO
Aircraft
SHANKS V ROGER VARI EZE
Registration
N944X
Category
Airplane
Highest injury
None
Fatalities
0
Phase of flight
Landing

Probable cause

An undetected fluid leak in the right brake line, which resulted in a reduction of braking effectiveness at the right wheel and a loss of directional control during the landing roll.

NTSB narrative

The private pilot reported that, during the landing roll, the experimental amateur-built airplane experienced a partial loss of right brake effectiveness. The pilot attempted to counter the directional control imbalance as the roll continued, but he became concerned that the airplane might run off the end of the runway and the drop-off at the end, so he applied maximum brake pressure. The airplane then veered left, departed the runway, and impacted a hangar. Postaccident examination revealed that a slow fluid leak had developed at the inlet fitting of the right brake caliper, and the fluid level in the reservoir for the right brake master cylinder had dropped to just under half of its capacity. This leak most likely allowed air to be introduced into the system either through the fitting or the depleted brake reservoir, which resulted in reduced effectiveness of the right brake. Maintenance records indicated that the pilot replaced the hydraulic lines on the right side about 147 flight hours before the accident. The airplane was equipped with a free-castering nosewheel and ground steering was accomplished through differential braking once rudder effectiveness diminished at lower speeds. Therefore, with the loss of braking effectiveness on one side, the pilot had limited means to effectively slow the airplane and maintain directional control once the airplane decelerated to a speed below which rudder authority was available.

Analysis

Primary failure mode
Loss of control
First missed decision gate
Pilot could have checked brake fluid levels before the flight.

NTSB coding

Evidence available

  • 3 docket documents
View NTSB final reportView NTSB docket

Docket documents3

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