Rockwell 100-180 accident near Franktown, Colorado, June 19, 1984
On June 19, 1984 at about 6:30 pm local time, a Rockwell 100-180, registered N4085X, was destroyed in an accident near Franktown, Colorado (Kostroski airport). It was a personal flight under general aviation rules (Part 91). 1 person was killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The NTSB has not yet published a probable cause for this accident. Investigations usually take one to two years; this page updates when the final report is released.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- June 19, 1984 · about 6:30 pm local time
- Place
- Franktown, Colorado · Kostroski · map
- Type
- Accident
- Injuries
- 1 person was killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Rockwell 100-180
- Registration
- N4085X · no longer on the register · serial 5185
- Damage
- Destroyed
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
THE PLT ATTEMPTED TO TAKEOFF DOWNWIND (WIND 310 DEGREES @22 KNOTS) WITH A DENSITY ALTITUDE CALCULATED TO BE 9190 FT MSL. ACCORDING TO THE ACFT MANUFACTURER, THE ACFT WOULD REQUIRE 2,535 FT FOR A GROUND RUN. RWY 17, A GRASS STRIP USED FOR THE TAKEOFF WAS 1800 FT LONG. WITNESSES STATED THAT THE ACFT BECAME AIRBORNE AND CLIMBED TO AN ALT OF 25 FT BEFORE THE RIGHT WING DIPPED AND THE ACFT DISAPPEARED OFF THE END OF THE RWY AND COLLIDED WITH TREES.
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; single-engine sea; instrument: airplane
- Flight time: 11,287 hours in all; 32 in this make and model; 2,540 as pilot in command; 665 on instruments
- Medical certificate: Class 1 (valid medical--w/ waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 1,346 hours
- Last inspection: annual inspection, July 14, 1983; 26 hours since
- Maximum gross weight: 5,550 lb
- Seats: 4
- Landing gear: fixed
- Engine: Lycoming O-360-A2F (piston); 0 hours total
The flight
- Departed from: Franktown CO at 6:30 pm
- Destination: 1C08 Everett CO
- Flight plan: none
- Runway 17, 1,800 ft by 150 ft
Weather at the time
- Light: daylight
- Wind: from 320° at 22 knots
- Visibility: 50 statute miles
- Sky: broken clouds at 8,000 ft; not recorded at 8,000 ft
- Temperature: 79°F (26°C), dew point 39°F (4°C)
- Altimeter: 30.00 inHg
- Observation at 6:45 pm from APA, 18 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.