Aerovodochody L-29 DELFIN accident near Reno, Nevada, June 18, 2011
On June 18, 2011 at about 9:50 pm local time, a Aerovodochody L-29 DELFIN, registered N37KF, was substantially damaged in an accident during maneuvering near Reno, Nevada (Reno-Stead airport). It was an air show or air race 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 failure of a modified engine mount to keep the engine properly aligned, which resulted in partial failure of the rudder support structure due to the deflection of the jet engine exhaust.
Source: NTSB aviation accident database, copy made October 4, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- June 18, 2011 · about 9:50 pm local time
- Place
- Reno, Nevada · Reno-Stead · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Aerovodochody L-29 DELFIN · all L-29 DELFINs on the register
- Registration
- N37KF · registry record · serial 993233
- Damage
- Substantial damage
- Flight
- Air show or air race flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
While being flown on an air race qualification/training flight, the experimental jet’s engine support mount, which had been recently installed to accommodate an increased-thrust engine modification, failed to keep the engine properly aligned. The resultant misalignment resulted in jet blast being directed onto and melting a portion of the rudder support structure. Although there was no indication of the problem in flight, during the landing roll, the pilot discovered that the rudder did not function properly, and directional control had to be maintained by alternate means. During the investigation, it was determined that five other racing airplanes of the same make and model had been modified in a similar manner and that there were slight structural variations and areas of poor welding associated with some of the mounts. As a result of this accident, the manufacturer of the engine modification instituted a program to obtain an independent professional engineering analysis of the engine mount design. Later, in response to another accident, the National Transportation Safety Board (NTSB) issued Safety Recommendation A-12-13, which asked the Reno Air Race Association (RARA) to require aircraft owners to provide an engineering evaluation for aircraft with any major modification. On August 27, 2012, pending receipt of further information showing that the process proposed by RARA specifically requires an owner of an aircraft with a major modification to provide an engineering evaluation that includes flight demonstrations and analysis within the anticipated flight envelope, the NTSB classified the recommendation Open-Acceptable Response.
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
- Sys/Comp malf/fail (non-power) during maneuvering defining event
- Aircraft structural failure during maneuvering
The NTSB's findings
- cause Aircraft › Aircraft power plant › Power plant › Mounts › Capability exceeded
- cause Aircraft › Aircraft structures › Empennage structure › Rudder misc structure › Failure
Pilot
- Certificate: commercial pilot
- Ratings: multi-engine land; single-engine land; instrument: airplane
- Flight time: 2,000 hours in all; 20 in the last 90 days; 10 in the last 30 days; 1,700 as pilot in command
- Last flight review: September 30, 2010
- Medical certificate: Class 2 (without waivers/limitations)
- Seat: frt
- Injury: no injuries
The aircraft
- Last inspection: condition inspection, June 10, 2011
- Seats: 2
- Landing gear: fixed
- Engine: Rolls Royce 601 Viper (turbojet); 0 hours total
The flight
- Departed from: 4SD Reno NV at 9:30 pm
- Destination: 4SD Reno NV
- Flight plan: none
- Runway 26, 7,600 ft by 150 ft
Weather at the time
- Light: daylight
- Wind: from 240° at 14 knots, gusting 26
- Visibility: 10 statute miles
- Sky: broken clouds at 19,000 ft
- Temperature: 82°F (28°C), dew point 34°F (1°C)
- Altimeter: 29.90 inHg
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 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 WPR11LA265.