Cessna 425 N425Z accident near Bismarck, North Dakota

Probable cause

A loss of braking due to inadequate servicing of brake fluid by the pilot/mechanic, which resulted in a loss of airplane control on the ground.

NTSB analysis

The pilot taxied to the ramp after an uneventful flight. After moving the throttles toward the ground idle position while in front of the marshaller, the airplane turned left, and the pilot observed that the right brake was inoperative. He attempted to stop the airplane by placing both propeller levers to the feather position and subsequently moved both throttles toward the reverse (beta) position. The airplane continued forward and struck a hangar, which resulted in substantial damaged to the left wing.

Postaccident examination of the braking system revealed the brake master cylinders were nearly empty of brake fluid, with no leaks observed. The pilot, who was also a mechanic, recorded completion of a phase inspection about nine months before the accident. The inspection included servicing the brake master cylinders, but the pilot reported he did not check the fluid levels of the master cylinders.

Text from the NTSB. Open the NTSB docket for CEN23LA103 for the full record.