Helicopter/Cyclone discussion (split from HMCS Fredricton thread)

[Colin Parkinson]

Not to put to much weight on the words of a interim statement, but it sound like the helicopter was manoeuvring into a flight path back to the ship, so it had forward momentum and was likley fairly low, which leads me to believe in a control failure without enough altitude for the pilot to compensate for, leading to a higher velocity impact. Due to the proximity to the ship, they may have some video which will help them narrow the cause. Hopefully the end was quick and painless.  :'( 

 

[Eye In The Sky]

BRIEF: Lifting of the operational pause on the CH-148 Cyclone helicopter fleet

Media advisory

June 15, 2020 – Ottawa – Department of National Defence / Canadian Armed Forces

Media are invited to a brief on the lifting of the operational pause on the Royal Canadian Air Force’s CH-148 Cyclone helicopter fleet. The operational pause was ordered as a precaution following the April 29 crash of a CH-148 Cyclone deployed on Operation REASSURANCE, which resulted in the tragic deaths of Sub-Lieutenant Abbigail Cowbrough, Captain Brenden Ian MacDonald, Captain Kevin Hagen, Captain Maxime Miron-Morin, Sub-Lieutenant Matthew Pyke, and Master Corporal Matthew Cousins.

In order to respect physical distancing, space will be limited. We encourage media to pool their coverage of this event and/or attend by teleconference.

When:
Tuesday, June 16, 2020 at 1:30 p.m. (EDT)

Where:        
West Block, Room 225
Parliament Hill
Wellington Street, Ottawa, Ontario

What:
Lieutenant-General Alain Pelletier (Commander of 1 Canadian Air Division and the Operational Airworthiness Authority), Brigadier-General Nancy Tremblay (Director-General of Aerospace Equipment Program Management and Technical Airworthiness Authority) and Colonel John Alexander (Director of Flight Safety and Airworthiness Investigative Authority) will provide information on the lifting of the operational pause on the CH-148 Cyclone fleet. There will also be an opportunity for questions.

Teleconference: Media can also participate by teleconference.

Toll-free (Canada/US) dial-in number: 1-866-206-0153
Local dial-in number: 613-954-9003
Passcode: 3246922#

Note to editors:
Members of the media are asked to confirm their attendance by contacting Lt(N) Melanie Aqiqi by email at melanie.aqiqi@forces.gc.ca.
Media are requested to arrive at the Canadian Parliamentary Press Gallery with photo identification no later than 1:10 p.m. (EDT).

 

[MilEME09]

https://www.cbc.ca/news/politics/cyclone-helicopter-crash-1.5613239

According to the article, mechanical failure has been ruled out, and is now focused on aircraft systems and human error as potential causes. I am guessing aircraft systems means the software since mechanical has been ruled out.

 

[Eye In The Sky]

Try this article:

https://vancouverisland.ctvnews.ca/military-to-return-cyclone-helicopters-to-service-in-the-coming-days-1.4986388#_gus&_gucid=&_gup=Facebook&_gsc=aN8SYNE

 

[Colin Parkinson]

https://www.cbc.ca/news/politics/cyclone-helicopter-crash-1.5613239

According to the article, mechanical failure has been ruled out, and is now focused on aircraft systems and human error as potential causes. I am guessing aircraft systems means the software since mechanical has been ruled out.

Potential to be another bug where the software causes the machine to do X or instructs/alerts the pilot to do X, when they should be doing Y.

 

[Mick]

If you watch the videos in the link EITS kindly provided, Col Alexander and LGen Pelletier are actually quite clear in explaining what investigators have discovered - and successfully recreated in the simulator - from data recovered from the BAU.

They also make it quite clear that the event in question is unrelated to previous flight control system issues.

And, it should be noted that the investigation of Human Factors does not imply human error.  They are not the same thing.

 

[SeaKingTacco]

If you watch the videos in the link EITS kindly provided, Col Alexander and LGen Pelletier are actually quite clear in explaining what investigators have discovered - and successfully recreated in the simulator - from data recovered from the BAU.

They also make it quite clear that the event in question is unrelated to previous flight control system issues.

And, it should be noted that the investigation of Human Factors does not imply human error.  They are not the same thing.

Correct on the human factors vs human error, Mick. This accident (most accidents, actually) are a long string of discrete events that line up to create an undesirable outcome. Interrupt that string of events at any point and you usually avoid the accident.  I heard very clearly From the briefing that the aircrew expected one thing and the aircraft did another. That does not mean (necessarily) that the aircrew made a mistake or that there was anything intrinsically wrong with the aircraft. A mismatch in expectations or perception at the wrong time can be disastrous.

 

[Lance Wiebe]

According to this article, it was a software "bias" that caused the crash.

https://www.cbc.ca/news/politics/cyclone-helicopter-crash-1.5613239

 

[SeaKingTacco]

According to this article, it was a software "bias" that caused the crash.

https://www.cbc.ca/news/politics/cyclone-helicopter-crash-1.5613239

No. It was not a software “bias”. A bias signal built up in pitch channel in Flight Director mode of the Flight Control Computer. It is important to get the terms correct. And since the flight safety investigation is only at an early stage, I am certain a lot more factors will come to light in the coming months. Remember- accidents are complex events consisting of many discrete events that contribute.

 

[Eye In The Sky]

I'll have to admit, I stopped reading the CBC article Lance linked after reading "Through a haze of technical jargon"... :

 

[Kirkhill]

I do not know anything on this matter.  But.  It occurs to me that with any given plan it is possible for the plan to encounter circumstances unforeseen.  Everybody can do their jobs right and bad things can still happen.

 

[SeaKingTacco]

I'll have to admit, I stopped reading the CBC article Lance linked after reading "Through a haze of technical jargon"... :

Yeah. Heaven forbid a news conference provide actual, factual data.  :

If they had dumbed down the language in the news conference, they would have been roundly criticized for that.

I guarantee that every aviation professional who watched it, understood what was being said.

 

[Good2Golf]

I guarantee that every aviation professional who watched it, understood what was being said.

:nod:

By the term ‘bias’ Colonel Alexander was referring to the flight control computer applying an offset relative to the command from the pilot’s controller, that resulted in an input to the pitch (longitudinal) cyclic actuator and resultant output to the blades that resulted in a pitch rate that differed from what the pilot believed should have occurred.  Essentially an automated adjustment to the pilot’s digital input into the flight control computer, based on the flight rules programmed, that are then translated into output control signals to the actuators.

The concept is not limited to aircraft.  Your personal car likely has throttle-by-wire.  There is an electrical sending unit attached to the accelerator pedal that provides a varying electrical signal (could be analogue, more likely digital these days) based on the physical position of the pedal to the engine control unit, that then takes other factors into account and sends a specified signal to the fuel injection system to provide a certain amount of power relative to your pedal input. A bias could be applied by the ECU to the accelerator input if, for instance, your car had a distance-controlled cruise control system and any additional speed would cause the distance to become less than a pre-set distance.  The cruise control module (autopilot) could adjust the car’s power output (as selected by you the driver with the pedal), unti you either turn off the cruise control, or perhaps press the accelerator pedal further down, thus overriding the distance-adjusted cruise speed.  That’s a simplified example, but it’s one that many people experience everyday driving their cars.

The point described by Colonel Alexander was that the modes in which control input biases are applied, particularly in complex (multi-axis) manoeuvres, were not immediately apparent to the pilot in time for him to take alternative action in a manner that would compensate fully for the biases.  He described that working with the OEM, Sikorsky, the RCAF will determine a comprehensive understanding of the programed flight rules for complex manoeuvres and the control input biases applied for various flight director modes, and ensure that operating procedures are consistent with the characteristics and expected behaviour of the aircraft.

 

[SeaKingTacco]

I'll have to admit, I stopped reading the CBC article Lance linked after reading "Through a haze of technical jargon"... :

Mr Brewster significantly misquoted what was said during the news conference in his article. He also drew inferences that were never made during the news conference.

 

[Mick]

I found it very interesting that although the investigation has not yet determined the "why" of the accident, investigators have a reasonable understanding as to the "what".  I'll admit, I was surprised that Col Alexander's prepared statement went into the detail it did, regarding levels of automation, and manual pilot inputs.  Still lots of questions to be explored / answered.  I also appreciated the gentle push-back against using terms like "glitch".

 

[SeaKingTacco]

I found it very interesting that although the investigation has not yet determined the "why" of the accident, investigators have a reasonable understanding as to the "what".  I'll admit, I was surprised that Col Alexander's prepared statement went into the detail it did, regarding levels of automation, and manual pilot inputs.  Still lots of questions to be explored / answered.  I also appreciated the gentle push-back against using terms like "glitch".

I thought the news conference was excellent, as well. It answered most of my questions.

 

[OldSolduer]

I thought the news conference was excellent, as well. It answered most of my questions.

Reading between the lines and deciphering technical terms,  would it be fair to say its a similar issue to what Boeing underwent recently with the Boeing Max?

 

[SeaKingTacco]

Reading between the lines and deciphering technical terms,  would it be fair to say its a similar issue to what Boeing underwent recently with the Boeing Max?

I am not really qualified to comment on Boeing vs Sikorsky design philosophy, so I won’t.

 

[Baz]

Reading between the lines and deciphering technical terms,  would it be fair to say its a similar issue to what Boeing underwent recently with the Boeing Max?

I don't *think* they are in any way related.  One has got to do with Pilot expectations if flight control laws, the other has to do with sensors causing a trim input in order to make the aircraft behave differently for training purposes,  and the pilot not reacting properly to a runaway trim.

I think there is preconceived notions about fly by wire... that it is either bad or good, depending on who you listen to. It is both, it has strength and weaknesses, but it is different.

For those thinking flight control software is needlessly complex, consider just as examples the mechanical flight control mixing unit or the mechanical fuel control units on the Sea King... plus the discreet electrical ASE.

Come to think of it... I've experienced the equivalent to a sensor failure with the ASE... the gyro tumbled causing rapidly changing headings which the ASE interpreted as a Yaw input and tried to correct causing yaw kicks.  The pilot secured the ASE, isolated the Yaw channel,  reengaged ASE, and landed as soon as practical.  Anagolous to securing the automatic trim.

And everything I just wrote seems like a "haze of technical jargon."  Does the public really need to understand all that?

 

[MilEME09]

Silver lining in this is that by being able to recreate the problem in the simulator, and having all the data that they collected, hopefully they will be able to prevent what occurred from ever happening again.