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WPR21LA072 · Navion Navion A

21 Dec 2020 · Livermore, CA, United States

Navion Navion A · Accident: loss of engine power (total) on approach

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Event

NTSB case
WPR21LA072
Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
Accident
InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
Completed
Event fatalities
Unknown
Ground fatalities
Unknown
OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
General aviation
WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
Visual Meteorological Cond

Navion Navion A

Aircraft type
Navion A
Category
Airplane
RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
N4106K
Operator
Unknown
Onboard fatalities
Unknown
Route
From not recordedTo not recorded
Aircraft age
Not recorded
Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
Part 91: General Aviation
Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
Approach · VFR pattern crosswind
Defining eventThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
Loss of engine power (total)
DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
Substantial

Cause areas

  • Aircraft › Aircraft systems
  • Personnel issues › Task performance

Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.

NTSB narrative

The airplane had an annual inspection and new wingtip fuel tanks installed about 6 months before the accident. The accident flight was the first flight since the maintenance. The pilot completed a normal runup inspection and the engine developed full power during takeoff. However, at an altitude of approximately 500 ft above ground level (agl), as the pilot turned onto the crosswind leg of the traffic pattern, the engine began to surge and lose power. As the pilot reduced the power for landing on the downwind leg, the engine lost total power. When the pilot realized the airplane would not make it to the runway, he prepared for a landing on the grass area parallel to the runway. The airplane touched down and the left wing impacted concrete blocks. A postaccident examination of the engine revealed a leaking gascolator fuel inlet line caused by a loose hose clamp connection on the fuel line from the fuel selector to the gascolator. The loose connection allowed a large amount of air to be introduced into the fuel line going to the engine and fuel pumps, which caused the engine to surge and eventually lose power. The examination also revealed several maintenance discrepancies. The leaking fuel inlet line was made of rubber instead of aluminum tubing, and the fuel selector's connection was improper. Additionally, the wingtip fuel tank installation revealed several inconsistencies with the installation, such as loose clamps and improper hardware installed. These discrepancies were an indication of improper recent maintenance.

Probable cause

The improper installation of the gascolator fuel inlet line and hose clamp connection, which resulted in the total loss of engine power.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record WPR21LA072
Event ID
20201222102448
Case number
WPR21LA072
Dataset
full-current
Source SHA-256
5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
Source notes (4)
  • Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
  • Filled from the NTSB case API where the bulk record had no value: investigation status, coordinates, cause areas. Values present in the bulk record are kept.
  • The date is the local date, which is the same as the UTC date the NTSB stores.
  • API snapshot SHA-256: 871fa9c7c001d66603d13fbb3b5cabb025fb56c6751228e893b17aefe76cac64; retrieved 2026-09-16T13:30:49.896Z.