Diamond Aircraft Ind INC DA 42 NG and Piper PA 12 accident near Bozeman, Montana, April 4, 2018
On April 4, 2018 at about 6:29 pm local time, 2 aircraft, Diamond Aircraft Ind INC DA 42 NG (N621ZC) and Piper PA 12 (N7709H), were involved in the same accident near Bozeman, Montana (Bozeman Yellowstone Intl airport). No one was hurt; 4 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The student pilot and flight instructor's failure to see and avoid the stationary airplane during taxi, which resulted in a ground collision.
The student pilot and flight instructor's failure to see and avoid the stationary airplane during taxi, which resulted in a ground collision.
Source: NTSB aviation accident database, copy made October 12, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- April 4, 2018 · about 6:29 pm local time · cases in 2018
- Place
- Bozeman, Montana · Bozeman Yellowstone Intl · cases near this airport · map
- Type
- Accident · collision on the ground
- Injuries
- No one was hurt; 4 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft 1
- Diamond Aircraft Ind INC DA 42 NG NG, built 2012
- Registration
- N621ZC · registry record · serial 42.NC002
- Damage
- Substantial damage
- Flight
- Instructional flight · general aviation rules (Part 91)
- Aircraft 2
- Piper PA 12 NO SERIES, built 1946 · all PA 12s on the register
- Registration
- N7709H · registry record · serial 12-601
- Damage
- Substantial damage
- Flight
- Instructional flight · general aviation rules (Part 91)
The NTSB's narrative for the Diamond Aircraft Ind INC DA 42 NG final · quoted from the NTSB record
The tailwheel-equipped airplane had completed a series of touch-and-go takeoffs and landings with the student pilot in the front seat and flight instructor in the rear seat. The airplane was equipped with large tundra tires which, in combination with the tailwheel configuration, provided limited forward visibility when on the ground. The tower controller cleared the pilots to cross the landing runway, and then subsequently cleared the airplane across the parallel runway, which led it onto a taxiway where a low-wing airplane, having just cleared the parallel runway after landing, was stopped and preparing to contact ground control. Neither of the pilots onboard the tailwheel airplane saw the low-wing airplane before they collided with it on the taxiway, resulting in substantial damage to both airplanes. The student pilot stated that he perceived that he should expedite the taxi across the parallel runway due to airplanes on approach to that runway, although review of air traffic control voice recordings revealed that the controller issued no instructions to expedite the taxi. Because of the faster taxi speed, the pilots did not perform any "S"-turn maneuvers to enhance forward visibility, which likely would have allowed them to see the low-wing airplane and prevented the collision.
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 NTSB's narrative for the Piper PA 12 final · quoted from the NTSB record
The tailwheel-equipped airplane had completed a series of touch-and-go takeoffs and landings with the student pilot in the front seat and flight instructor in the rear seat. The airplane was equipped with large tundra tires which, in combination with the tailwheel configuration, provided limited forward visibility when on the ground. The tower controller cleared the pilots to cross the landing runway, and then subsequently cleared the airplane across the parallel runway, which led it onto a taxiway where a low-wing airplane, having just cleared the parallel runway after landing, was stopped and preparing to contact ground control. Neither of the pilots onboard the tailwheel airplane saw the low-wing airplane before they collided with it on the taxiway, resulting in substantial damage to both airplanes. The student pilot stated that he perceived that he should expedite the taxi across the parallel runway due to airplanes on approach to that runway, although review of air traffic control voice recordings revealed that the controller issued no instructions to expedite the taxi. Because of the faster taxi speed, the pilots did not perform any "S"-turn maneuvers to enhance forward visibility, which likely would have allowed them to see the low-wing airplane and prevented the collision.
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 for the Diamond Aircraft Ind INC DA 42 NG from the NTSB's investigation tables, in plain English
What happened, in order
- Ground collision during taxi (from runway) defining event
The NTSB's findings
- cause Personnel issues › Psychological › Attention/monitoring › Monitoring other aircraft › Pilot of other aircraft
Flight instructor
- Certificate: flight instructor, commercial pilot
- Ratings: multi-engine land; single-engine land; instructor: airplane multi-engine; instructor: airplane single-engine; instructor: instrument airplane; instrument: airplane
- Flight time: 1,780.8 hours in all; 211.8 in this make and model; 130.3 in the last 90 days; 41.2 in the last 30 days; 1,723 as pilot in command; 1,527.8 on instruments
- Last flight review: July 27, 2017
- Medical certificate: Class 2 (without waivers/limitations)
- Seat: rgt
- Injury: no injuries
Pilot
- Certificate: private
- Ratings: single-engine land; instrument: airplane
- Flight time: 127.6 hours in all; 3 in this make and model; 15.6 in the last 90 days; 5.8 in the last 30 days
- Last flight review: October 17, 2017
- Medical certificate: Class 3 (without waivers/limitations)
- Seat: left
- Injury: no injuries
The aircraft
- Airframe total time: 1,801.5 hours
- Last inspection: annual inspection, March 26, 2018
- Maximum gross weight: 4,207 lb
- Seats: 4
- Landing gear: retractable
- Engine 1: Austro E4B (piston); 0 hours total
- Engine 2: Austro E4B (piston); 0 hours total
- Operator: Summit Aviation INC
The flight
- Departed from: BZN Bozeman MT at 5:15 pm
- Destination: BZN Bozeman MT
- Flight plan: none
- Runway 12, 8,994 ft by 150 ft
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: from 070° at 7 knots
- Visibility: 10 statute miles
- Sky: overcast at 7,000 ft; clear
- Temperature: 46°F (8°C), dew point 23°F (-5°C)
- Altimeter: 29.94 inHg
- Observation at 6:56 pm from KBZN, 1 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 2 |
The factual record for the Piper PA 12 from the NTSB's investigation tables, in plain English
What happened, in order
- Ground collision during taxi (from runway) defining event
The NTSB's findings
- cause Personnel issues › Psychological › Attention/monitoring › Monitoring other aircraft › Student/instructed pilot
- cause Personnel issues › Psychological › Attention/monitoring › Monitoring other aircraft › Instructor/check pilot
Dual student
- Certificate: student
- Flight time: 20 hours in all; 20 in this make and model
- Medical certificate: Class 3 (without waivers/limitations)
- Seat: frt
- Injury: no injuries
Flight instructor
- Certificate: 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: 25,638 hours in all; 200 in this make and model; 25,451 as pilot in command
- Last flight review: January 14, 2015
- Medical certificate: Class 3 (with waivers/limitations)
- Seat: frt
- Injury: no injuries
The aircraft
- Airframe total time: 1,635.8 hours
- Last inspection: annual inspection, July 25, 2017; 46 hours since
- Maximum gross weight: 1,750 lb
- Seats: 3
- Landing gear: fixed
- Engine: Lycoming O-290 SERIES (piston); 0 hours total
The flight
- Departed from: BZN Bozeman MT at 5:25 pm
- Destination: BZN Bozeman MT
- Flight plan: none
- Runway 11, 5,050 ft by 75 ft
- A second pilot was aboard
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 2 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The NTSB has not released the docket for this case yet. The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), is usually released when the investigation is nearly complete, and the list here is refreshed when it appears. Check at the NTSB.
Connections how this case links to the rest of the register
Aircraft
- N621ZC on the register today · the tail number may have moved to another aircraft since
- N7709H on the register today · the tail number may have moved to another aircraft since
- Piper PA-12 Super Cruiser 1,247 registered today · the model family and its accident history
- Piper 44,844 aircraft on the register
- Engine: Austro E4B 148 aircraft carry this series today · as the NTSB recorded it
- Engine: Austro E4B 148 aircraft carry this series today · as the NTSB recorded it
Place
- Bozeman Yellowstone International · nearest airport
- Accidents and incidents in Montana 1,119 since 1982 · 164 in the last ten years
- Montana 6,045 aircraft registered
The whole map of how records connect · these connections as data: /graph/accident/WPR18LA118.json.
The bigger picture in Aviation Analytics: accidents over time since 1982, by model, by phase of flight and conditions, by place and on the map.
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 does not name anyone involved, its policy at this time. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.