Rearwin 8135 accident near Casa Grande, Arizona, February 18, 2011
On February 18, 2011 at about 4:58 pm local time, a Rearwin 8135, registered NC25545, was substantially damaged in an accident during enroute (cruise) near Casa Grande, Arizona. 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).
Preview. This page is not yet listed for search engines.
The NTSB's probable cause their words, unchanged
The partial loss of engine power due to the separation of an exhaust valve rocker box as a result of the failure of the rocker box attaching studs.
Source: NTSB aviation accident database, copy made October 4, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- February 18, 2011 · about 4:58 pm local time
- Place
- Casa Grande, Arizona · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Rearwin 8135 · all 8135s on the register
- Registration
- NC25545 · no longer on the register · serial 822
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The engine began losing power immediately after takeoff, and the pilot executed a forced landing in a rough, uneven field. The main landing gear sheared off, and the airframe sustained substantial damage. Postaccident examination of the engine determined that the No. 4 cylinder exhaust valve rocker box was detached from the head of the cylinder. Three of the six attaching studs where broken, and the other three studs had pulled out of the head. One of the three studs that had pulled out was rounded off, indicating that it had been loose in the head for some time. The adjacent stud was also rounded off, but not as much, and the final stud had no signs of rounding off. It is likely that the separation of the rocker box resulted in the partial loss of engine power because the exhaust valve for the No. 4 cylinder could no longer open and close properly, which allowed exhaust gases to migrate through the No. 4 cylinder's intake valve and into the induction system.
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
- Loss of engine power (partial) during enroute (cruise) defining event
- Off-field or emergency landing during emergency descent
- Off-field or emergency landing during landing (landing roll)
The NTSB's findings
- cause Aircraft › Aircraft power plant › Engine (reciprocating) › Recip eng cyl section › Damaged/degraded
- Environmental issues › Physical environment › Terrain › Rough terrain › Effect on equipment
Pilot
- Certificate: commercial pilot
- Ratings: multi-engine land; single-engine land; single-engine sea; rotorcraft: glider; rotorcraft: helicopter
- Flight time: 16,500 hours in all; 37 in this make and model; 37 in the last 90 days; 15 in the last 30 days
- Last flight review: October 8, 2010
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: left
- Injury: no injuries
The aircraft
- Last inspection: annual inspection
- Seats: 2
- Landing gear: fixed
- Engine: Ken Royce 120 F (piston); 0 hours total
- Operator: Robert L Copeland Trust
The flight
- Departed from: E60 Eloy AZ at 4:43 pm
- Destination: CHD Chandler AZ
- Flight plan: none
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 54°F (12°C), dew point 37°F (3°C)
- Altimeter: 30.05 inHg
- Observation at 4:35 pm from KCGZ
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flig | 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.
About this page
Everything above comes from the NTSB's public accident database: the narrative, probable cause and findings are the NTSB's own words, and the coded tables behind its report (pilot, aircraft, flight, weather, injuries, sequence of events) are written out in plain English. Pilots' ages, home towns and medical details are left out on purpose. The documents and photographs are the NTSB's docket, the folder of records gathered during the investigation, shown as the NTSB released them (the NTSB redacts some personal details first) and listed under the NTSB's own titles. This site's own text never names pilots, passengers or anyone else involved. A preliminary report describes what is known soon after the event and can change; the final report, with the probable cause, usually follows one to two years later and this page is refreshed when it does. Case number WPR11LA140.