Hiller UH-12B accident near Rio Vista, Texas, September 19, 2012
On September 19, 2012 at about 3:45 pm local time, a Hiller UH-12B (helicopter), registered N94735, was substantially damaged in an accident during maneuvering (low-alt flying) near Rio Vista, Texas. It was a personal flight under general aviation rules (Part 91). No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The catastrophic failure and disintegration of the No. 6 engine piston, which resulted in a total loss of engine power.
Source: NTSB aviation accident database, copy made November 2, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- September 19, 2012 · about 3:45 pm local time · cases in 2012
- Place
- Rio Vista, Texas · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Hiller UH-12B · all UH-12Bs on the register
- Registration
- N94735 · registry record · serial 523
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot reported that he was on a survey flight when the helicopter engine suddenly stopped; he elected to autorotate to a field. The area he landed in had high vegetation, which “grabbed” the helicopter skids and the helicopter impacted the ground hard. Examination of the helicopter revealed that the main rotor impacted the tailboom during the accident and the tail rotor had separated from the helicopter. Examination of the engine revealed the No. 6 piston had disintegrated catastrophically, which caused additional internal damage to the engine.
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
- Powerplant sys/comp malf/fail during maneuvering (low-alt flying)
- Loss of engine power (total) during maneuvering (low-alt flying) defining event
- Autorotation Off-field or emergency landing
The NTSB's findings
- cause Aircraft › Aircraft power plant › Power plant › (general) › Failure other cases naming the engine
Dual student
- Certificate: student
- Ratings: rotorcraft: helicopter
- Medical certificate: Class 3 (with waivers/limitations)
- Injury: no injuries
The aircraft
- Last inspection: annual inspection
- Seats: 4
- Landing gear: fixed
- Engine: Franklin 6A4200 SERIES (piston); 0 hours total
The flight
- Departed from: Rio Vista TX
- Destination: Rio Vista TX
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 150° at 9 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 73°F (23°C), dew point 57°F (14°C)
- Altimeter: 30.18 inHg
- Observation at 3:55 pm from KCPT
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
5 documents, released by the NTSB on May 13, 2013. View them here, or download them; the NTSB redacts some personal details before release, and this site shows the NTSB's own titles rather than its file names.
| # | Document | What it is | |
|---|---|---|---|
| 1 | Pilot Statement (Memo) | PDF, 1 page | View Download |
| 2 | FAA Memo W/inspectors | PDF, 1 page | View Download |
| 3 | Mechanic Memo | PDF, 1 page | View Download |
| 4 | Weather Reports and Records | PDF, 1 page | View Download |
| 5 | Photo: Aft Tailboom and Tailrotor | PDF, 1 page | View Download |
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
Connections how this case links to the rest of the register
- N94735 on the register today · the tail number may have moved to another aircraft since
- Hiller UH-12 217 registered today · the model family and its accident history
- Hiller 242 aircraft on the register
- Engine: Franklin 6A4200 SERIES 13 aircraft carry this series today · as the NTSB recorded it
- Accidents and incidents in Texas 6,244 since 1982 · 1,061 in the last ten years
- Texas 29,986 aircraft registered
The whole map of how records connect · these connections as data: /graph/accident/CEN12LA650.json.
The bigger picture in Aviation Analytics: accidents over time since 1982, by model, by phase of flight and conditions, by place and on the map.
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 does not name anyone involved, its policy at this time. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.