High G Drama at Cold Lake

On 20 June 2017 two Royal Canadian Air Force (RCAF) Boeing CF-188 Hornets, call signs Mig-1 and Mig-6, were returned to CFB Cold Lake, AB after Maple Flag 50 training missions.

Two other CF-188 Hornet aircraft execute high speed manoeuvres at 4 Wing Cold Lake, during Exercise MAPLE FLAG 50 on 1 June 2017 (Credit: RCAF)

Two other CF-188 Hornet aircraft execute high speed manoeuvres at 4 Wing Cold Lake, during Exercise MAPLE FLAG 50 on 1 June 2017 (Credit: RCAF)

When overhead runway 13R at 1500 ft above ground level and 470 knots, the RCAF safety investigators report that:

Mig-1 entered the overhead break in a right hand turn followed three seconds later by Mig-6 [CF-188 CF188796]. During the overhead break Mig-6 set the throttles to idle, initially set the bank angle to 81 degrees, and pulled up to 6.8g in order to slow the aircraft in preparation for turning final with gear down and locked.

Mig-6 did not perform the anti-g straining maneuver, and was flying with a loose fitting g-suit with comfort zippers undone.

Two seconds into the overhead break and at 6.8g, Mig 6 almost lost consciousness. Mig-6 experienced short term (approximately 5 seconds) impairment of cognitive and motor functions, and the aircraft began descending towards the ground.

Mig-6 heard the audible warning from the Terrain Alert Warning System, and with improved cognitive and motor functions, Mig-6 pulled 7.0g and avoided the ground by 270 ft.

Both aircraft landed safely.  The RCAF investigation is examining further human factors and technical aspects.

UPDATE 23 July 2018: The RCAF say:

The evidence demonstrated no aircraft or aviation life support equipment (ALSE) malfunction. The incident occurred due to human factors. The pilot was knowingly flying with a loose fitting g-suit. The g-suit was loose fitting due to pilot weight loss, and lack of adherence to an ALSE – Canadian Forces Technical Orders requiring a g-suit on body fit check to be completed every six months.

The safety recommendation is to incorporate the g-suit inspection requirements and pilot responsibilities regarding g-suit fitting into an appropriate aircrew publication to provide lasting education/awareness for CF188 pilots.

CF-188 (Credit: RCAF)

Other Safety Resources


Aerossurance will be presenting at the Royal Aeronautical Society (RAeSHuman Factors in Aircraft Maintenance conference on 2 November 2017 in London.  Our topic is: Helicopter Flying Control Maintenance HF Accidents: A Human Centred Design Opportunity

Aerossurance is also pleased to be supporting the annual Chartered Institute of Ergonomics & Human Factors’ (CIEHFHuman Factors in Aviation Safety Conference for the third year running.  We will be presenting for the second year running too, this time on the subject of the FSF‘s Maintenance Observation Programme concept.

CIEHFlogo This year the conference takes place 13 to 14 November 2017 at the Hilton London Gatwick Airport, UK with the theme: How do we improve human performance in today’s aviation business?


Aerossurance has extensive air safety, operations, airworthiness, human factors, aviation regulation and safety analysis experience.  For practical aviation advice you can trust, contact us at: enquiries@aerossurance.com