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Air transportation safety investigation A18W0116

The TSB has completed this investigation. The report was published on 1 August 2019.

Table of contents

Power loss and loss of control in flight

Aries Aviation International
Piper PA-31, C-FNCI
Calgary/Springbank Airport, Alberta, 40 nm SW

View final report

The occurrence

On , after completing 2 hours of survey work near Penticton, British Columbia (BC), an Aries Aviation International Piper PA-31 aircraft (registration C-FNCI, serial number 31-8112007) proceeded on an instrument flight rules flight plan from Penticton Airport (CYYF), BC, to Calgary/Springbank Airport (CYBW), Alberta, at 15 000 feet above sea level. The pilot and a survey technician were on board. When the aircraft was approximately 40 nautical miles southwest of CYBW, air traffic control began sequencing the aircraft for arrival into the Calgary airspace and requested that the pilot slow the aircraft to 150 knots indicated airspeed and descend to 13 000 feet above sea level. At this time, the right engine began operating at a lower power setting than the left engine. About 90 seconds later, at approximately 13 500 feet above sea level, the aircraft departed controlled flight. It collided with terrain near the summit of Mount Rae at 1336 Mountain Daylight Time. A brief impact explosion and fire occurred during the collision with terrain. The pilot and survey technician both received fatal injuries. The Canadian Mission Control Centre received a 406 MHz emergency locator transmitter signal from the occurrence aircraft and notified the Trenton Joint Rescue Coordination Centre. Search and rescue arrived on site approximately 1 hour after the accident.

Media materials

News release


Hypoxia likely contributed to August 2018 fatal collision with terrain in Kananaskis Country, Alberta
Read the news release

Deployment notice


TSB deploys a team of investigators to an air accident southwest of the Calgary/Springbank Airport, Alberta

Richmond, British Columbia, 1 August 2018 - The Transportation Safety Board of Canada (TSB) is deploying a team of investigators to an accident involving a Piper PA-31 Navajo approximately 40 nautical miles southwest of the Calgary/Springbank Airport. The TSB will gather information and assess the occurrence.

Investigation information

Map showing the location of the occurrence


Photo of Jonathan (Jon) Lee

Jonathan (Jon) Lee is the Western Regional Manager for the Transportation Safety Board of Canada (TSB) in Edmonton, Alberta. He has been an aircraft investigator for 19 years, and has been managing the Edmonton office for eight of those years. He has been involved in approximately 50 investigations. Mr. Lee has also participated in foreign investigations that involve Canadian aerospace products. Working with the National Transportation Safety Board (United States), the Aviation Safety Council (Taiwan), Aviation and Railway Accident Investigation Board (South Korea), and the Aviation Accident Investigation Board (Mongolia) has made Mr. Lee appreciate the importance of the TSB’s role in global aviation.

Before working in accident investigation, Mr. Lee gained industry experience as a pilot in operations ranging from regional airlines and transcontinental cargo to medevac and flight instruction. He has flown over 35 types of aircraft and has accumulated 6500 flight hours. He maintains a valid and current airline transport pilot license.


  Download high-resolution photos from the TSB Flickr page.

Class of investigation

This is a class 3 investigation. These investigations analyze a small number of safety issues, and may result in recommendations. Class 3 investigations are generally completed within 450 days. For more information, see the Policy on Occurrence Classification.

TSB investigation process

There are 3 phases to a TSB investigation

  1. Field phase: a team of investigators examines the occurrence site and wreckage, interviews witnesses and collects pertinent information.
  2. Examination and analysis phase: the TSB reviews pertinent records, tests components of the wreckage in the lab, determines the sequence of events and identifies safety deficiencies. When safety deficiencies are suspected or confirmed, the TSB advises the appropriate authority without waiting until publication of the final report.
  3. Report phase: a confidential draft report is approved by the Board and sent to persons and corporations who are directly concerned by the report. They then have the opportunity to dispute or correct information they believe to be incorrect. The Board considers all representations before approving the final report, which is subsequently released to the public.

For more information, see our Investigation process page.

The TSB is an independent agency that investigates air, marine, pipeline, and rail transportation occurrences. Its sole aim is the advancement of transportation safety. It is not the function of the Board to assign fault or determine civil or criminal liability.