Amateur-built IV accident near Laramie, Wyoming, February 10, 2019
On February 10, 2019 at about 11:00 pm local time, a 2014 amateur-built IV, registered N549CJ, was substantially damaged in an accident during enroute (climb to cruise) near Laramie, Wyoming (Laramie Regional airport). It was a personal 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
An environmental stress cracking failure of the acrylic windshield, which resulted in a rapid decompression during cruise flight.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- February 10, 2019 · about 11:00 pm local time
- Place
- Laramie, Wyoming · Laramie Regional · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built IV P, built 2014
- Registration
- N549CJ · registry record · serial 218
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot reported that, during cruise flight at 15,500 feet mean sea level in the pressurized airplane, he heard a loud “bang” as the windscreen fractured. The pilot diverted to a nearby airport, where he landed the airplane uneventfully. An examination of the windshield pieces revealed that the fracture origin area displayed features consistent with a preexisting crack that developed due to environmental stress cracking (ESC). ESC is a fracture mechanism in polymer materials that occurs when a susceptible polymer material is exposed to a combination of tensile stress and exposure to a substance that degrades the integrity of the material. The ESC was likely a result of contact with a degrading substance, the origin of which could not be determined. Although a stress analysis of the windscreen structure was not completed, the location of the fracture origin was likely an area of high stress on the windscreen due to the curvature at that location. Sustained high stress in acrylic can promote crack development, particularly when the acrylic is also exposed to certain chemical agents. The overall appearance of the windscreen edge showed limited visual evidence of adhesive on the surface, suggesting a relatively low bond strength between the windscreen at the frame. Evidence of voids in the epoxy at the interior bond surface were observed; if portions of the windscreen became disbonded, this could have affected the stress state of the windscreen and contributed to increased stress at the fracture origin area.
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
- Aircraft structural failure during enroute (climb to cruise) defining event
The NTSB's findings
- Aircraft › Aircraft structures › Windows › windshield system › (general) › Failure
Pilot
- Certificate: commercial pilot
- Ratings: multi-engine land; single-engine land; instrument: airplane
- Flight time: 2,700 hours in all; 400 in this make and model
- Medical certificate: Class 3 (with waivers/limitations)
- Seat: left
- Injury: no injuries
The aircraft
- Airframe total time: 307 hours
- Last inspection: condition inspection, March 1, 2018; 91 hours since
- Maximum gross weight: 3,550 lb
- Seats: 4
- Landing gear: retractable
- Engine: Continental TSIO-550-E (piston); 307 hours total
The flight
- Departed from: CPR Casper WY at 10:30 pm
- Destination: FTG Denver CO
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 150° at 24 knots, gusting 34
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 28°F (-2°C), dew point 12°F (-11°C)
- Altimeter: 29.63 inHg
- Observation at 10:53 pm from KLAR, 4 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
2 documents, released by the NTSB on April 12, 2022. 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 20-011 | PDF, 15 pages | View Download |
| 2 | Pilot/operator Aircraft Accident Report, NTSB Form 6120.1 | PDF, 8 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.