Amateur-built SPORT HORNET accident near Mariposa, California, February 21, 2012
On February 21, 2012 at about 10:40 pm local time, a amateur-built SPORT HORNET, registered N72PD, was substantially damaged in an accident during enroute near Mariposa, California (Mariposa-Yosemite Airport). It was a personal flight under general aviation rules (Part 91). No one was hurt; 2 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
Improper clearance and inadequate heat shielding between engine components and the exhaust system, which resulted in an in-flight fire.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- February 21, 2012 · about 10:40 pm local time
- Place
- Mariposa, California · Mariposa-Yosemite Airport · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built SPORT HORNET
- Registration
- N72PD · no longer on the register · serial 055
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
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.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
What happened, in order
- Fire/smoke (non-impact) during enroute defining event
The NTSB's findings
- cause Aircraft › Aircraft power plant › Engine exhaust › (general) › Related operating info
- cause Personnel issues › Task performance › Maintenance › Fabrication › Owner/builder
Pilot
- Certificate: sport pilot
- Ratings: single-engine land
- Flight time: 1,630 hours in all; 462 in this make and model; 12 in the last 90 days; 7 in the last 30 days; 1,498 as pilot in command
- Last flight review: September 4, 2011
- Medical certificate: Sport Pilot
- Seat: frt
- Injury: no injuries
The aircraft
- Airframe total time: 97 hours
- Last inspection: condition inspection, August 7, 2011; 10 hours since
- Maximum gross weight: 1,250 lb
- Seats: 2
- Landing gear: fixed
- Engine: Rotax 912ULS (piston); 0 hours total
The flight
- Departed from: MPI Mariposa CA at 9:40 pm
- Destination: MPI Mariposa CA
- Flight plan: none
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 66°F (19°C), dew point 0°F (-18°C)
- Altimeter: 30.05 inHg
- Observation at 9:00 pm
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | |||
| Passengers | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.