Piper PA-23-250 accident near Sweetwater, Texas, April 20, 2004
On April 20, 2004 at about 11:35 pm local time, a Piper PA-23-250, registered N6257H, was substantially damaged in an accident near Sweetwater, Texas (Avenger Field Airport). It was a ferry 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
The propeller overspeed for undetermined reasons. A contributing factor was the lack of suitable terrain for the forced landing.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- April 20, 2004 · about 11:35 pm local time
- Place
- Sweetwater, Texas · Avenger Field Airport · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Piper PA-23-250 · all PA-23-250s on the register
- Registration
- N6257H · registry record · serial 277654057
- Damage
- Substantial damage
- Flight
- Ferry flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The propeller on the number two engine on a light twin-engine airplane experienced an overspeed while in cruise flight. The 1,430-hour pilot reported that while in cruise flight at 5,500 feet msl, he noticed the propellers were "out of sync." The pilot stated that he made minor adjustments with the propeller levers to synchronize the propellers; however, the propellers continued to be "out of sync." The right propeller began to overspeed by approximately 1,000 RPM's, and adjustments with the right prop lever had no effect. The pilot retarded the throttle, but could not maintain proper engine RPM, so he elected to land at the nearest airport, located approximately 12 miles away. The pilot noticed that the number two engine was starting to overheat, so he retarded the throttle again and increased airspeed to aid in cooling. The airplane started to shake, and he looked outside and observed the propeller was "wobbling." Subsequently, the pilot executed a forced landing into a muddy wheat field. The airplane had an annual inspection on December 12, 2003, and was determined to be in an un-airworthy condition. The airplane was given a special flight permit for maintenance, issued on April 20, 2004, which was to expire on April 30, 2004. The propeller governors were tested on a governor test stand and functioned normally; however, they were out of specification. The maximum RPM on the left governor was 2,394 and the maximum RPM on the right governor was 2,310. The specified RPM is 2,435. The specified feather RPM is 1,700. The left governor achieved 1,671 RPMs and the right governor achieved 1,634 RPMs. Inspection after disassembly was uneventful. Both governors were found to be "old and worn, exhibited similar wear patterns, but were functional." The reason for the reported propeller overspeed could not be determined.
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
Pilot
- Certificate: flight instructor, commercial pilot
- Ratings: multi-engine land; single-engine land; instructor: airplane multi-engine; instructor: airplane single-engine; instructor: instrument airplane; instrument: airplane
- Flight time: 1,430 hours in all; 4 in this make and model; 229 in the last 90 days; 75 in the last 30 days; 1,323 as pilot in command; 972 on instruments
- Last flight review: January 24, 2004
- Medical certificate: Class 1 (with waivers/limitations)
- Seat: left
- Injury: no injuries
The aircraft
- Airframe total time: 4,000 hours
- Last inspection: annual inspection, December 12, 2003
- Maximum gross weight: 5,200 lb
- Seats: 6
- Landing gear: retractable
- Engine: Lycoming IO-540-C4B5 (piston); 0 hours total
The flight
- Departed from: MAF Midland TX at 10:30 pm
- Destination: JSV Sallisaw OK
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 250° at 7 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 79°F (26°C), dew point 23°F (-5°C)
- Altimeter: 29.75 inHg
- Observation at 11:25 pm from SWW
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| 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.
Other NTSB records under N6257H the same tail number, which may have belonged to a different aircraft at the time
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.