Piper PA-18-150 accident near Boulder, Colorado, February 8, 1989
On February 8, 1989 at about 9:10 pm local time, a Piper PA-18-150, registered N4355Z, was substantially damaged in an accident near Boulder, Colorado (Boulder Municipal airport). It was an instructional 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
FAILURE OF THE DUAL STUDENT TO MAINTAIN DIRECTIONAL CONTROL AND THE FAILURE OF THE PILOT IN COMMAND (CFI), TO PROVIDE ADEQUATE REMEDIAL ACTION IN A TIMELY MANNER, TO CORRECT THE SWERVE. A SECOND PROBABLE CAUSE WAS THE CFI'S FAILURE TO PROVIDE ADEQUATE SUPERVISION DURING THE LANDING ROLL. INADEQUATE CREW COORDINATION IS CONSIDERED A FACTOR.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- February 8, 1989 · about 9:10 pm local time
- Place
- Boulder, Colorado · Boulder Municipal · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Piper PA-18-150 · all PA-18-150s on the register
- Registration
- N4355Z · registry record · serial 18-8673
- Damage
- Substantial damage
- Flight
- Instructional flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
THE ATP RATED CFI WAS PERFORMING A RENTAL CHECKOUT WITH A PRIVATE PLT. THE CHECK PLT TOLD THE PLT TO MAKE A LANDING AND 'IF SUFFICIENT RUNWAY REMAINED,' TO MAKE ANOTHER TAKEOFF. A LANDING WAS COMPLETED ON RWY 8R, A 4,100 X 75 FT ASPHALT RWY. THE CHECK PILOT HAD BEEN FOLLOWING THROUGH ON THE CONTROLS BUT DURING THE LANDING ROLL HE RELEASED THE CONTROLS AND WAITED FOR THE PLT TO STOP. HE SAID THAT AS SOON AS HE REMOVED HIS HANDS FROM THE CONTROLS, THE STICK WENT FORWARD AND HE HEARD THE ENGINE SPEED UP. THE AIRPLANE SWERVED TO THE LEFT. THE CHECK PLT TOOK THE CONTROLS AND ATTEMPTED TO CORRECT THE SWERVE, TO NO AVAIL. THE PLANE STRUCK A SNOW DRIFT ON THE LEFT SIDE OF THE RWY AND NOSED OVER.
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: airline transport pilot, flight instructor, commercial pilot
- Ratings: multi-engine land; single-engine land; instructor: airplane multi-engine; instructor: airplane single-engine; instructor: glider; instructor: instrument airplane; instrument: airplane; rotorcraft: glider
- Flight time: 2,215 hours in all; 165 in this make and model; 64 in the last 90 days; 46 in the last 30 days; 2,096 as pilot in command; 582 on instruments
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: rear
The aircraft
- Airframe total time: 3,545 hours
- Last inspection: 100-hour inspection, November 11, 1988; 74 hours since
- Maximum gross weight: 1,625 lb
- Seats: 2
- Landing gear: fixed
- Engine: Lycoming O-320-A2B (piston); 0 hours total
The flight
- Departed from: 1V5 at 8:45 pm
- Destination: 1V5
- Flight plan: none
- Runway 0, 4,100 ft by 75 ft
- A second pilot was aboard
Weather at the time
- Light: daylight
- Visibility: 50 statute miles
- Sky: clear
- Temperature: 18°F (-8°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 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.