Piper PA-20-180 accident near Thornton, Colorado, September 19, 1998
On September 19, 1998 at about 7:14 pm local time, a Piper PA-20-180, registered N6028D, was destroyed in an accident near Thornton, Colorado. It was a flight of an unrecorded kind under general aviation rules (Part 91). 1 person was seriously injured. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The separation of a propeller blade due to corrosion initiated fatigue, followed by the separation of several of the engine's mounts, and the subsequent inability of the pilot to control the aircraft. A contributing factor was the trees.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- September 19, 1998 · about 7:14 pm local time
- Place
- Thornton, Colorado · map
- Type
- Accident
- Injuries
- 1 person was seriously injured.
- Weather
- visual conditions (good weather)
- Aircraft
- Piper PA-20-180 · all PA-20-180s on the register
- Registration
- N6028D · no longer on the register · serial 22-4681
- Damage
- Destroyed
- Flight
- Flight of an unrecorded kind · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
While in cruise flight at 1,200 feet agl, on a banner tow flight, 21.6 inches of one of the two bladed 38-inch propeller blades separated from the aircraft. The engine separated from three of the four engine mounts and swung around against the right side of the aircraft. The remaining propeller blade penetrated the cockpit but did not strike the pilot. The aircraft became uncontrollable and impacted in a field after striking trees in the back yard of a home. The propeller blade failed due to fatigue from corrosion pitting. The pilot received serious injuries.
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
Pilot
- Certificate: commercial pilot
- Ratings: multi-engine land; single-engine land; instrument: airplane
- Flight time: 1,500 hours in all; 250 in this make and model; 1,500 as pilot in command
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 1,600 hours
- Last inspection: annual inspection, November 1, 1997; 80 hours since
- Maximum gross weight: 2,000 lb
- Seats: 2
- Landing gear: fixed
- Engine: Lycoming O-360-A3A (piston); 0 hours total
The flight
- Departed from: O1V Aurora CO at 7:00 pm
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 080° at 10 knots
- Visibility: 80 statute miles
- Sky: scat at 11,000 ft
- Temperature: 81°F (27°C), dew point 39°F (4°C)
- Altimeter: 29.00 inHg
- Observation at 6:45 pm from BJC, 15 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| 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.
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.