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Air transportation safety investigation A19W0099

The TSB has completed this investigation. The report was published on 10 February 2020.

Table of contents

Mid-air collision

Cu Nim Gliding Club
Cessna 182N, C-FPZE and Cu Nim Gliding Club
Schleicher ASK 21 (glider), C-FLTY
Black Diamond/Cu Nim Aerodrome, Alberta, 0.5 NM SW

View final report

The occurrence

On , a Cessna 182N was conducting tow operations at the Black Diamond/Cu Nim Gliding Club airport (CEH2). A Schleicher ASK 21 dual-seat glider belonging to the club was operating at CEH2 with an instructor and student on board. The Cessna departed Runway 07 with the glider in tow and proceeded to climb to 2000 feet above the aerodrome, at which time the glider released from the tow plane. A few minutes later, the glider and the airplane collided approximately 0.5 nm southwest of the threshold of Runway 07. In the collision, the vertical and horizontal stabilizers were separated from the glider. The glider entered a dive from which it did not recover. The tow plane sustained damage to the propeller and right wing. However, the pilot of the airplane managed to perform a successful forced landing with idle power onto Runway 14. The student and instructor in the glider were both fatally injured. The tow pilot was not injured.

Media materials

News release


Investigation report: July 2019 fatal mid-air collision in Black Diamond, Alberta
Read the news release

Deployment notice


TSB will deploy a team following an accident involving 2 aircraft near Black Diamond, Alberta

Edmonton, Alberta, 26 July 2019 - The Transportation Safety Board of Canada (TSB) will deploy a team of investigators following an accident involving a Cessna 182 and a Schleicher ASK 21 glider near Black Diamond, Alberta. The TSB will gather information and assess the occurrence.

Investigation information

Map showing the location of the occurrence


Photo of Jeremy Warkentin

Jeremy Warkentin joined the Transportation Safety Board of Canada (TSB) in 2017 as a Regional Senior Technical Investigator, in the Aviation Investigations Branch, at the regional office in Edmonton, Alberta.

Mr. Warkentin is a graduate of the British Columbia Institute of Technology’s Aircraft Maintenance Engineer (AME) program and has more than 20 years of aviation experience working for several fixed wing operations as a licensed Aircraft Maintenance Engineer, Quality Assurance Manager and Base/Production Manager. He holds both an M1 and M2 license, and has experience on aircraft ranging in size from the Cessna 152 to the Airbus A321.

Class of investigation

This is a class 4 investigation. These investigations are limited in scope, and while the final reports may contain limited analysis, they do not contain findings or recommendations. Class 4 investigations are generally completed within 220 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.