Cirrus Design CORP SR22 accident near Mack, Colorado, September 23, 2013
On September 23, 2013 at about 11:35 pm local time, a 2009 Cirrus Design CORP SR22, registered N426TF, was substantially damaged in an accident during enroute (cruise) near Mack, Colorado (Mack Mesa Airport). It was a business flight under general aviation rules (Part 91). 1 person had minor injuries; 2 others were unhurt. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
A total loss of engine power due to the failure of the engine crankshaft, which resulted from maintenance personnel’s application of insufficient torque on the engine case through bolts.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- September 23, 2013 · about 11:35 pm local time
- Place
- Mack, Colorado · Mack Mesa Airport · map
- Type
- Accident
- Injuries
- 1 person had minor injuries; 2 others were unhurt.
- Weather
- visual conditions (good weather)
- Aircraft
- Cirrus Design CORP SR22 NO SERIES, built 2009
- Registration
- N426TF · no longer on the register · serial 3586
- Damage
- Substantial damage
- Flight
- Business flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot reported that, while the airplane was in cruise flight, the engine suddenly lost power and then seized. During the subsequent forced landing, the airplane sustained substantial damage. Examination of the engine revealed that the crankshaft was fractured through the cheek extending from the No. 2 main bearing journal to the No. 3 connecting rod journal. The No. 2 main bearings had extruded from their crankcase positions and exhibited mechanical damage. The No. 2 main bearing support displayed signatures consistent with bearing shift. The No. 2 main bearing saddle support and several other bearing saddle supports exhibited fretting, consistent with movement between the engine case halves due to insufficient torque on the case through bolts. Maintenance logbook records showed that the Nos. 1, 2, 3, and 4 cylinders were replaced about 1 1/2 years before the accident. When maintenance personnel replaced those cylinders, they would have had to remove the nuts on the case through bolts because they also serve as hold-down bolts for the cylinders. Based on the evidence, it is likely that maintenance personnel applied insufficient torque on the case through bolts after replacing the cylinders, which led to case movement and ultimately to the No. 2 main bearings shifting and extruding, the crankshaft fracturing, and the engine seizing.
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 (total) during enroute (cruise) defining event
- Collision with terrain or object (not controlled flight into terrain) during landing
The NTSB's findings
- cause Aircraft › Aircraft power plant › Engine (reciprocating) › Recip engine power section › Incorrect service/maintenance
- cause Aircraft › Aircraft power plant › Engine (reciprocating) › Recip engine power section › Failure
- cause Personnel issues › Task performance › Maintenance › (general) › Maintenance personnel
Pilot
- Certificate: private
- Ratings: single-engine land; instrument: airplane
- Flight time: 2,888 hours in all; 1,390 in this make and model; 94 in the last 90 days; 34 in the last 30 days; 2,838 as pilot in command
- Medical certificate: Class 3 (without waivers/limitations)
- Seat: left
- Injury: minor injuries
The aircraft
- Airframe total time: 1,491 hours
- Last inspection: annual inspection, June 26, 2013; 190 hours since
- Maximum gross weight: 3,400 lb
- Seats: 4
- Landing gear: fixed
- Engine: Cont Motor IO-550-N60B (piston); 1,245 hours total
- Operator: Trans Med LLC
The flight
- Departed from: ALS Alamosa CO at 10:17 pm
- Destination: OGD Ogden UT
- Runway 25, 2,600 ft by 60 ft
Weather at the time
- Light: daylight
- Wind: from 350° at 5 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 64°F (18°C), dew point 52°F (11°C)
- Altimeter: 29.96 inHg
- Observation at 11:53 pm from GJT, 19 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | |||
| Passengers | 2 |
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.
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.