According to the Commission of Inquiry report obtained by the Canadian News Agency, when the pilot turns, it is usually referred to as “returning to the target.” He turns the tail of the helicopter with his feet upside down, overtaking the autopilot to complete the maneuver in less than 20 seconds.

However, the report stated that no tests were conducted during the certification of the aircraft to determine what would happen if the pilot exceeded the autopilot “temporarily” under certain complicated circumstances.

“The automation principles and philosophy that governed Cyclone design were never intended to be used [autopilot] It has been covered for a long time, so it has never been tested,” it said.

Although this is indeed the case-as the report states-pilots sometimes override the autopilot system without manually pressing the button on the control stick, called a loop.

The report said that during the crash, the autopilot-known as the flight commander-was set to an airspeed of approximately 260 kilometers per hour, and then a pilot tilted the aircraft’s nose up to prepare for the turn.

It should fly back to HMCS Fredericton and practice hoisting people to the deck. Instead, the frigate’s CH-148 cyclone helicopter-located in Nova Scotia-crashed off the coast of Greece when returning from a NATO training mission.

The crash caused the worst single-day loss of life in the Canadian Armed Forces since the roadside bomb attack in Afghanistan on July 4, 2007 killed 6 soldiers.

The report states that if the pilot manually chooses to turn off the autopilot during a turn, the crash may be avoided. But it also stated that it is not uncommon for pilots to overtake the autopilot, and the manual does not clearly state that the flight director must be turned off manually.

The aircraft’s software was critical to the crash

In addition, the report stated that the pilot did not seem to realize that the computer would try to regain control near the end of the turn.

The report stated that when the helicopter turned over, the pilot pulled back as much as possible in the loop, trying to correct the aircraft flying the computer into the sea. Within a few seconds, the helicopter hit the sea with great force.

The investigation committee stated that it found no evidence that the pilot realized that he had lost control of the aircraft until it was too late.

According to the report, the key to the crash is the aircraft’s software, which has been certified by the military. If the autopilot is covered, the computer will accumulate digital instructions, which is called “instruction deviation accumulation”. The report states that when the aircraft is coupled to the autopilot, the more commands the pilot manually sends to the computer, the more this deviation accumulates.

The report stated that “feedforward observation” would occur after the pilot exceeded the airspeed set by the autopilot, and added that in some cases, “the ability of the pilot to control the aircraft ?Ǫ will be reduced or lost.”

The investigation committee stated that the pilot training did not cover certain risks of flying the aircraft in “sufficient detail”, leaving the flight crew not aware that the autopilot would try to maintain control of the helicopter.

The report stated that the return-to-target operations that led to the crash were carried out by others in the maritime helicopter community. Since the crash, this operation has been banned.

Report recommendations

The report made six recommendations, five of which involve better training of pilots so that they are aware of potential problems that might arise if they surpass the autopilot. It recommends the creation of special cockpit signals that pilots can use to warn the opponent to stay above the flight director for long periods of time.

The report also recommends that the military consider engineering changes, “in some cases, automatically disarm the flight commander, such as when the flight commander is covered on multiple axes, or over a long period of time.”

According to a senior military source, this recommendation was not shared in the second independent report that the Military Flight Safety Agency is expected to release next week.

The second report stated that pilots must be well-trained, and if they do not get the response they want, they can almost immediately press a button on the control stick to get out of the autopilot. However, it stated that in some cases, automatic disengagement from the autopilot may be a risk, especially when the pilot believes that the autopilot will continue to operate.

On the contrary, the second report argues that the software and its “prejudice accumulation” need to be resolved by American Airlines Sikorsky Aircraft Corporation (the manufacturer of Cyclone).

The source said: “We need to look at the software to see if we can completely eliminate this from the software, and be careful to understand that when you make any such changes, you may introduce a butterfly effect and cause problems elsewhere.”

‘Fly well together’

The report of the investigation committee signed on November 20, 2020 by the three members of the team concluded that the pilot was not distracted and the crew “flew well together”. It added that the captain has strong commanding capabilities for the helicopter, and the co-pilot demonstrated “good situational awareness” throughout the mission.

The second report is expected to further analyze the factors behind the crash.

According to military sources, the recommendations of the two reports must be combined into a set of findings for consideration by senior officials in the Royal Canadian Air Force.

A spokeswoman for Sikorsky referred all questions about the report to the Canadian Army.

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