Pilot Debrief

PRIDMORE LANCAIR IV near Caldwell, ID — 2010-06-28

Final reportWPR10LA319
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Date
2010-06-28
Location
Caldwell, ID, USA
Airport
KEUL
Aircraft
PRIDMORE LANCAIR IV
Registration
N86PB
Category
Airplane
Highest injury
None
Fatalities
0
Phase of flight
Ground

Probable cause

The failure of maintenance personnel to ensure that a hydraulic line fitting was adequately secured during a conditional inspection, which resulted in a leak and subsequent on-ground fire.

NTSB narrative

Several minutes after starting the engine, the pilot noticed an odor in the cockpit, which he thought was similar to that of burning plastic. He could hear the hydraulic pump cycle once, which he thought was unusual. He pulled the hydraulic circuit breaker out and within 30 seconds he observed smoke emanating from the engine area. He shut down the airplane and noticed flames at the bottom of the engine cowl. According to the pilot, the last conditional inspection was completed 6 days prior to the accident, and the airplane accumulated 2 flight hours since that inspection. An examination of the firewall revealed that its right side had a white coloration, which turned to a black soot color on the left side, consistent with the fire originating on the right side of the engine. On the right side of the belly area, near the nose landing gear compartment, a red/pink hydraulic fluid stain started and continued down toward the tail. The stain became small beads of pooling liquid at the low point of the belly, indicating a hydraulic leak. Above the stain, on the right side of the engine firewall, were two hydraulic fittings where hoses connected to either side of the nose landing gear actuator. Based on this evidence, it is likely that the fitting on the lower hydraulic line was not properly tightened, which allowed it to back off due to normal engine vibration, resulting in the line loosening during engine start. Pressurized hydraulic fluid then sprayed onto the right exhaust shroud and ignited.

Analysis

Primary failure mode
Mechanical failure
First missed decision gate
Pilot could have inspected hydraulic system before engine start to prevent fire.

NTSB coding

Evidence available

  • Photos
  • 2 docket documents
View NTSB final reportView NTSB docket

Docket documents2

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