WPR12LA113 · Haycraft SPORT HORNET
Haycraft SPORT HORNET · Accident: fire/smoke (non-impact) en route
From Mariposa Yosemite Airport (MPI) to Mariposa Yosemite Airport (MPI)
Event
- NTSB case
- WPR12LA113
- 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
- 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
Haycraft SPORT HORNET
- Aircraft type
- Haycraft SPORT HORNET
- 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
- N72PD
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Mariposa Yosemite Airport (MPI), Mariposa, CATo Mariposa Yosemite Airport (MPI), Mariposa, CA
- 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
- En route
- 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
- Fire/smoke (non-impact)
- 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
- 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 pilot was returning to the airport when he noticed the smell of smoke in the cockpit. The smoke intensity increased, and after about 15 seconds, he opted to perform a forced landing into a pasture. During the landing roll, the nosewheel separated from the airplane, which slid to a stop. The pilot stated that after egressing, he observed fire emanating from underneath the engine area.
A postaccident examination revealed that the engine’s predominant area of thermal deformation was around the No. 4 cylinder (right side). Examination of the bottom of the engine revealed that the right side exhibited hotter thermal exposure signatures than the rest of the engine. Due to the thermal destruction, it could not be determined precisely where the fire originated; however, the area where the damage was the greatest was where the fuel lines, coolant lines, ignition harness, and carburetor were located. It was also noted that no heat shielding was installed between the exhaust system and the engine, which more than likely had an effect on the initiation of the fire.
Both the engine and the exhaust manufacturers recommended installing heat shielding between the exhaust and engine components. The limits section of the Installation Manual states that if there is not proper heat shielding to protect the modules and fuel lines from the exhaust heat, the engine may be susceptible to a fire. However, because this airplane is experimental, there is no requirement for the installation of the heat shield.
Probable cause
Improper clearance and inadequate heat shielding between engine components and the exhaust system, which resulted in an in-flight fire.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record WPR12LA113
- Event ID
- 20120221X84549
- Case number
- WPR12LA113
- 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. 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: 2818a374d356e9a0114824a6823f53589b1e2153bb0716827946c0c201f1a1b8; retrieved 2026-09-15T17:18:05.087Z.