Amateur-built 601XL-B accident near The Dalles, Oregon, March 31, 2017
On March 31, 2017 at about 11:55 pm local time, a 2012 amateur-built 601XL-B, registered N610TT, was substantially damaged in an accident during enroute (climb to cruise) near The Dalles, Oregon (Columbia Gorge Regional/The Da airport). It was a personal flight under general aviation rules (Part 91). 2 people had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
A partial loss of engine power due to the reverse bending fatigue failure of the propeller hub bolts, which resulted from the bolts not fitting tightly into the propeller hub holes. Also causal was the pilot's decision to use improper bolts for this type of installation/operation.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- March 31, 2017 · about 11:55 pm local time
- Place
- The Dalles, Oregon · Columbia Gorge Regional/The Da · map
- Type
- Accident
- Injuries
- 2 people had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built 601XL-B, built 2012
- Registration
- N610TT · no longer on the register · serial 6-7884
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The commercial pilot, who was also the owner/builder of the experimental amateur-built airplane, reported that, after departure and while climbing through 3,500 ft mean sea level, he heard the engine sound abruptly change and observed a loss of rpm and higher-than-normal exhaust gas temperature readings. The pilot turned back toward the airport and attempted to troubleshoot the problem; however, the airplane continued to produce less power than expected. The pilot established a normal traffic pattern for the runway. After turning to final, the airplane started descending and had insufficient power to reach the runway. The airplane subsequently impacted terrain short of the runway. Postaccident examination of the airplane revealed that all six propeller bolts that held the propeller hub to the drive hub were fractured. Further examination of the bolts revealed that the fracture surfaces all exhibited similar features consistent with reverse bending fatigue, likely from not fitting tightly into the propeller hub holes. The pilot reported that he had converted the engine and that, given its unique conversion, the bolts that were typically used to connect the propeller hub to the drive hub were too short; therefore, he chose to use the bolts that were on the hub at the time of the accident. Given the condition of the bolts and the pilot's statement, it is likely the bolts did not fit tightly in the propeller hub holes, which led to their failure due to reverse bending fatigue.
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 (climb to cruise) defining event
- Off-field or emergency landing during enroute (climb to cruise)
- Landing area undershoot during landing
- Collision with terrain or object (not controlled flight into terrain) during landing
The NTSB's findings
- cause Aircraft › Aircraft propeller/rotor › Propeller system › Propeller hub section › Failure
- cause Aircraft › Aircraft propeller/rotor › Propeller system › Propeller hub section › Fatigue/wear/corrosion
- cause Aircraft › Fluids/misc hardware › Misc hardware › (general) › Incorrect use/operation
- Personnel issues › Task performance › Maintenance › Modification/alteration › Pilot
- cause Personnel issues › Action/decision › Info processing/decision › Decision making/judgment › Pilot
Pilot
- Certificate: commercial pilot
- Ratings: single-engine land
- Flight time: 1,661 hours in all; 129 in this make and model; 1,600 as pilot in command
- Last flight review: September 28, 2016
- Medical certificate: None
- Seat: left
- Injury: minor injuries
The aircraft
- Airframe total time: 129 hours
- Last inspection: condition inspection, June 14, 2016; 33 hours since
- Maximum gross weight: 1,320 lb
- Seats: 2
- Landing gear: fixed
- Engine: Ott 3250 (piston); 33 hours total
The flight
- Departed from: DLS The Dalles OR at 11:50 pm
- Destination: DLS The Dalles OR
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 330° at 8 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 64°F (18°C), dew point 36°F (2°C)
- Altimeter: 30.20 inHg
- Observation at 11:53 pm from DLS, 1 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | |||
| Passengers | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
4 documents, released by the NTSB on October 24, 2017. 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 | Materials Laboratory Factual Report | PDF, 6 pages | View Download |
| 2 | Pilot/operator Aircraft Accident Report, NTSB Form 6120.1 | PDF, 10 pages | View Download |
| 3 | Engine Examination Observations - Courtesy of the Federal Aviation Administration | PDF, 4 pages | View Download |
| 4 | Evidence Control Form - Propeller Hub Bolts | PDF, 5 pages | View Download |
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
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.