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Accidents · NTSB WPR20CA053 · Final report

Cessna 170 accident near Missoula, Montana, December 28, 2019

On December 28, 2019 at about 8:45 pm local time, a 1955 Cessna 170, registered N4476B, was substantially damaged in an accident during takeoff near Missoula, Montana (Missoula Intl 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

The pilot receiving instruction's failure to maintain directional control during the takeoff roll, which resulted in a runway excursion and ground-loop, and the flight instructor’s failure to adequately monitor the pilot.

Source: NTSB aviation accident database, copy made November 2, 2026. Docket and reports at the NTSB.

What the record shows

Date
December 28, 2019 · about 8:45 pm local time · cases in 2019
Place
Missoula, Montana · Missoula Intl · cases near this airport · map
Type
Accident
Injuries
No one was hurt; 2 people were on board or involved.
Weather
visual conditions (good weather)
Aircraft
Cessna 170 B, built 1955 · all 170s on the register
Registration
N4476B · registry record · serial 26820
Damage
Substantial damage
Flight
Instructional flight · general aviation rules (Part 91)

The NTSB's narrative final · quoted from the NTSB record

The pilot, who was receiving instruction for his tailwheel endorsement, reported that, during the takeoff roll, the airplane began to veer left. He applied corrective control inputs, and the flight instructor called for him to abort the takeoff, but the airplane ground looped and departed the runway. The airplane sustained substantial damage to the right wing and aileron. The instructor reported that the event happened too fast for him to correct the diversion and that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation.

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

  1. Loss of control on ground during takeoff defining event
  2. Attempted remediation/recovery during takeoff
  3. Runway excursion during takeoff

The NTSB's findings

  • cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Directional control › Not attained/maintained
  • cause Personnel issues › Psychological › Attention/monitoring › Monitoring other person › Instructor/check pilot
  • cause Personnel issues › Task performance › Use of equip/info › Aircraft control › Student/instructed pilot

Flight instructor

  • Certificate: flight instructor, commercial pilot, flight engineer
  • Ratings: single-engine land; instructor: airplane single-engine; instructor: helicopter; instrument: airplane; instrument: helicopter; rotorcraft: helicopter
  • Flight time: 2,607 hours in all; 474 in this make and model; 19.8 in the last 90 days; 4.5 in the last 30 days; 1,708 as pilot in command; 70.5 on instruments
  • Last flight review: June 18, 2019
  • Medical certificate: Class 2 (with waivers/limitations)
  • Seat: rgt
  • Injury: no injuries

Pilot

  • Certificate: flight instructor, commercial pilot, private
  • Ratings: multi-engine land; single-engine land; instructor: airplane single-engine; instrument: airplane
  • Flight time: 1,071.5 hours in all; 2.7 in this make and model; 3.2 in the last 90 days; 0.8 in the last 30 days; 980.7 as pilot in command; 55.7 on instruments
  • Last flight review: June 14, 2019
  • Medical certificate: BasicMed
  • Seat: left
  • Injury: no injuries

The aircraft

  • Airframe total time: 3,967.9 hours
  • Last inspection: annual inspection, December 3, 2019; 4 hours since
  • Maximum gross weight: 2,200 lb
  • Seats: 4
  • Landing gear: fixed
  • Engine: Continental O-300-A (piston); 3,967 hours total

The flight

  • Departed from: MSO Missoula MT
  • Destination: MSO Missoula MT
  • Flight plan: none
  • Runway 12, 9,501 ft by 150 ft
  • A second pilot was aboard

Weather at the time

  • Light: daylight
  • Visibility: 10 statute miles
  • Sky: overcast at 5,000 ft; clear
  • Temperature: 30°F (-1°C), dew point 18°F (-8°C)
  • Altimeter: 30.15 inHg
  • Observation at 8:53 pm

Injuries

FatalSeriousMinorNone
Flight crew2

Photographs from the investigation 2 pictures from the NTSB's docket, as the NTSB released them

The NTSB's photographs with the NTSB's captions, at screen size. Open a picture to see it full size or to report one that should not be shown.

Documents from the investigation the NTSB's docket: the evidence folder behind the report

2 documents, released by the NTSB on March 17, 2020. 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.

#DocumentWhat it is
1 Pilot/operator Aircraft Accident Report, NTSB Form 6120.1 PDF, 9 pages View Download
2 Photos PDF, 2 pages · our copy View Download

The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.

Connections how this case links to the rest of the register

Aircraft
Place

The whole map of how records connect · these connections as data: /graph/accident/WPR20CA053.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.