CEN22LA128 · Ryan L17 B
Ryan L17 B · Accident: fuel contamination en route
From St Louis Regional Airport (ALN) to an unrecorded destination
Event
- NTSB case
- CEN22LA128
- 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
- API-reported fatalities
- 0 · all aircraft and ground
- Ground fatalities
- 0
- 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
Ryan L17 B
- Aircraft type
- Ryan L17
- 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
- N5042K
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From St Louis Regional Airport (ALN), Bethalto, ILTo not recorded
- Aircraft age
- About 74 years (built 1948)
- 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
- En route · cruise
- 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
- Fuel contamination
- 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 power plant
- Not determined › Not determined
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The pilot receiving instruction reported that the purpose of the instructional flight was to practice various flight maneuvers, which were successfully performed. About halfway back to the departure airport, the pilot noticed the engine was “running rough.” The pilot proceeded to lean the airplane’s fuel mixture to correct the problem and noticed that the fuel flow gauge was “pegged.” The pilot continued to lean the mixture and adjusted the throttle, but no response was received from his inputs. The airplane began to lose altitude, and the pilot receiving instruction performed a forced landing to a flat muddy field. During the landing rollout, the nosewheel turned left in the mud, the airplane spun around, both wings and the propeller impacted the ground, and the airplane came to rest upright. The airplane sustained substantial damage to both wings.
The flight instructor, who was also a mechanic, reported that, when the engine was running roughly, he tried to lean the mixture with no response. The flight instructor also reported that the fuel flow gauge needle had advanced into the manifold pressure side of the gauge and that the throttle had no response. The flight instructor assumed that the fuel control unit had a mechanical issue.
Postaccident examination of the airplane found no anomalies that would have precluded normal operation. Testing of the fuel injection system found internal damage to the fuel control valve. The internal damage was likely consistent with fuel injection system contamination.
In addition, the interior of the fuel pump had a dark deposit that was firmly adhered to the surface and could not be removed. When viewed under magnification, the deposit was found to be consistent with corrosion of the surface material. Thus, corrosion was likely present in the contamination. The engine manufacturer’s guidance stated that fuel injection system contamination may lead to “component damage, erratic engine operation, loss of power, or engine shutdown.” Although the source of the contamination could not be determined based on the available evidence, the contamination likely caused the fuel control system to fail, which led to the total loss of engine power during the accident flight.
Probable cause
A total loss of engine power due to fuel injection system contamination from an unknown source.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CEN22LA128
- Event ID
- 20220222104674
- Case number
- CEN22LA128
- 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, 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: ec3978903320c59403b30f273b264cc7e299904c6be4103fe085c59d2a2823eb; retrieved 2026-09-16T14:58:50.411Z.