Pilot Debrief

Vans RV4 near Idabel, OK — 2020-07-22

Final reportCEN20LA301
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Date
2020-07-22
Location
Idabel, OK, USA
Airport
4O4
Aircraft
Vans RV4
Registration
N54WP
Category
Airplane
Highest injury
None
Fatalities
0
Phase of flight
Maneuvering

Probable cause

The pilot’s improper installation of an oil line, resulting in the loss of oil and subsequent total loss of engine power.

NTSB narrative

After a full stop landing to refuel on a cross-country flight in the experimental airplane, the pilot noticed a chaffed oil line leading to the propellor governor. The pilot, with assistance from a local mechanic, removed the damaged oil line and replaced it with a used serviceable line. The pilot pre-flighted the airplane, took off, and continued his flight. About 70 minutes into the flight, the pilot observed oil on the windscreen. As the pilot maneuvered for a precautionary landing at a nearby airport, the engine stopped producing power. About 1/2 mile from the airport, the pilot attempted to land on a roadway. The airplane impacted power lines and the ground. The pilot stated that he could not see the power lines through the oil-covered windscreen. The airplane came to rest in a ditch adjacent to the roadway, resulting in structural damage to the fuselage and empennage. Examination of the airplane and engine after the accident revealed a crack in the oil line leading to the propeller governor from its connection at the engine case. There was no clamp installed to secure the line. A conditional airworthiness inspection had recently been completed on the experimental airplane. According to Federal Aviation Administration Airworthiness Directive (AD) 90-04-06R1, a clamp should have been installed on the oil line leading to the propeller governor. The pilot reported that when he replaced the oil line, there was no clamp present, so he did not install a clamp and was not aware of the applicable AD. He stated that had he been aware of the AD, he would have installed a new oil line and clamp. The available evidence indicates that the pilot’s improper installation of the oil line resulted in the in-flight loss of oil and subsequent total loss of engine power.

Analysis

Primary failure mode
Mechanical failure
First missed decision gate
Pilot could have installed a clamp on the oil line to prevent failure.

NTSB coding

Evidence available

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

Docket documents5

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