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aircanadaa330
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Canadian C-148 Helicopter missing presumed crashed

Wed Apr 29, 2020 11:00 pm

Helicopter was operating of HMCS FREDERICTON in the Mediterranean Sea in support of a NATO operation.

Praying for all on board...

https://www.ctvnews.ca/world/canadian-n ... -1.4917670
Cheers;
 
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kc135topboom
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Re: Canadian C-148 Helicopter missing presumed crashed

Wed Apr 29, 2020 11:20 pm

Praying the SAR Forces finds the crew alive, maybe a little wet, but alive.
 
dr1980
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Re: Canadian C-148 Helicopter missing presumed crashed

Thu Apr 30, 2020 6:17 pm

One person has been identified as deceased and five are missing...very sad news in an already very sad month for Nova Scotia. My thoughts are with the family and friends of the crew members.

https://www.cbc.ca/news/canada/canadian ... -1.5550395
Dave/CYHZ
 
ThePointblank
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Re: Canadian C-148 Helicopter missing presumed crashed

Wed May 13, 2020 8:59 am

Suspicion is focusing in on the flight control system of the CH-148, based upon the reported details of the crash:

https://www.cbc.ca/news/politics/cyclon ... -1.5566656

The important bit:

The CH-148 Cyclone helicopter has what the air force calls a "triple redundant" flight control system — and during a 2017 training mission off Nova Scotia, all three of those computers momentarily failed at once.

It was a major software glitch, alarming enough to ground the fleet for nine weeks.

At the time, the military described the incident publicly as a "severe bump" which reset the controls and caused the aircraft to briefly and suddenly lose altitude. The pilot managed to recover and land safely.

One defence expert now says that incident may prove to be vitally important as investigators probe the cause of last month's Cyclone crash in the Ionian Sea. The crash, which happened while the chopper was taking part in NATO operations, claimed the lives of six Canadian service members — four aircrew and two sailors.

Chopper 'flew into the ocean,' say sources

Multiple defence sources tell CBC News that at the time of the crash, the Cyclone was conducting a high-speed, low-level photo pass of HMCS Fredericton, a manoeuvre known in the air force as a "Brownie Run" after a NATO standard camera.

Without warning, the helicopter suddenly pitched forward and "flew into the ocean," said the sources, who were granted anonymity because of the sensitivity of the investigation.

The March 9, 2017 incident involving a software glitch aboard a Cyclone is a matter of public record. What wasn't fully revealed at the time, the sources said, was the fact that all three interconnected computers inexplicably reset themselves — something that could have led to a catastrophic crash.

When the nine-month grounding of the fleet ended three years ago, the Cyclones continued to operate for a period of time under a series of flight restrictions while their manufacturer, Sikorsky Aircraft, addressed the software issue through a pre-planned upgrade.
 
Ozair
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Re: Canadian C-148 Helicopter missing presumed crashed

Tue Jun 09, 2020 9:24 pm

An preliminary report on the crash of the Canadian CH-148 in the Mediterranean has been released. As suspected they are indicating a control issue outside of pilot actions as the cause.

Canada releases preliminary report on CH-148 Cyclone crash

The Canadian Armed Forces (CAF) Sikorsky CH-148 Cyclone maritime and anti-submarine warfare (ASW) helicopter that crashed in the Ionian Sea on 29 April did not respond as the crew would have anticipated while performing a final complex manoeuvre turn to close with the HMCS Fredericton, according to a preliminary report.

The From the Investigator (FTI) report released 8 June determined that the CH-148 was returning from a routine surface reconnaissance mission followed by additional training of flight deck evolutions for aircrew proficiency before landing on the HMCS Fredericton. The helicopter had flown by the port side of the ship, from stern to bow, before making a left-hand turn to establish a downwind leg in preparation for approach to the ship.

The aircraft then began a final left turn to prepare for the approach. During this turn to close with the ship, the helicopter did not respond as the crew would have anticipated. This event occurred at low altitude, was unrecoverable, and the CH-148 entered a high-energy descent and crashed into the water astern the ship

...

https://www.janes.com/defence-news/news ... 0ca63cec3e
 
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Aesma
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Re: Canadian C-148 Helicopter missing presumed crashed

Mon Jun 15, 2020 7:50 pm

Well that's not great. Is the fleet grounded again ?
New Technology is the name we give to stuff that doesn't work yet. Douglas Adams
 
Ozair
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Re: Canadian C-148 Helicopter missing presumed crashed

Mon Jun 15, 2020 9:18 pm

Aesma wrote:
Well that's not great. Is the fleet grounded again ?

Except for operational commitments I don't believe the fleet has resumed flight operations since the incident.
 
ThePointblank
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Re: Canadian C-148 Helicopter missing presumed crashed

Tue Jun 16, 2020 12:14 am

Aesma wrote:
Well that's not great. Is the fleet grounded again ?

If it's a defect in the design of the flight control systems, I wonder what the repercussions will be for Sikorsky... I would suspect that the Canadian government will want additional compensation from Sikorsky for the loss of an aircraft plus its crew, and the subsequent costs for the grounding on top of the delay penalties so far...
 
Ozair
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Re: Canadian C-148 Helicopter missing presumed crashed

Tue Jun 16, 2020 1:45 am

ThePointblank wrote:
Aesma wrote:
Well that's not great. Is the fleet grounded again ?

If it's a defect in the design of the flight control systems, I wonder what the repercussions will be for Sikorsky... I would suspect that the Canadian government will want additional compensation from Sikorsky for the loss of an aircraft plus its crew, and the subsequent costs for the grounding on top of the delay penalties so far...

And by extension what impact this may have on the VH-92 program and other less high profile operators.
 
ThePointblank
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Re: Canadian C-148 Helicopter missing presumed crashed

Tue Jun 16, 2020 11:05 am

Operational pause is being lifted per this press briefing notice:

https://www.canada.ca/en/department-nat ... fleet.html

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)
 
ThePointblank
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Re: Canadian C-148 Helicopter missing presumed crashed

Tue Jun 16, 2020 11:16 am

Ozair wrote:
ThePointblank wrote:
Aesma wrote:
Well that's not great. Is the fleet grounded again ?

If it's a defect in the design of the flight control systems, I wonder what the repercussions will be for Sikorsky... I would suspect that the Canadian government will want additional compensation from Sikorsky for the loss of an aircraft plus its crew, and the subsequent costs for the grounding on top of the delay penalties so far...

And by extension what impact this may have on the VH-92 program and other less high profile operators.

My understanding is that the military -92's are different from the civilian birds in having a fly-by-wire flight control system, while the civilian S-92's are mechanical. You also got more powerful engines, and a higher gross weight as well.
 
Ozair
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Re: Canadian C-148 Helicopter missing presumed crashed

Tue Jun 16, 2020 11:47 am

ThePointblank wrote:
Ozair wrote:
ThePointblank wrote:
If it's a defect in the design of the flight control systems, I wonder what the repercussions will be for Sikorsky... I would suspect that the Canadian government will want additional compensation from Sikorsky for the loss of an aircraft plus its crew, and the subsequent costs for the grounding on top of the delay penalties so far...

And by extension what impact this may have on the VH-92 program and other less high profile operators.

My understanding is that the military -92's are different from the civilian birds in having a fly-by-wire flight control system, while the civilian S-92's are mechanical. You also got more powerful engines, and a higher gross weight as well.

Do you know which variant the VH-92 is based on?
 
ThePointblank
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Re: Canadian C-148 Helicopter missing presumed crashed

Tue Jun 16, 2020 11:01 pm

Ozair wrote:
ThePointblank wrote:
Ozair wrote:
And by extension what impact this may have on the VH-92 program and other less high profile operators.

My understanding is that the military -92's are different from the civilian birds in having a fly-by-wire flight control system, while the civilian S-92's are mechanical. You also got more powerful engines, and a higher gross weight as well.

Do you know which variant the VH-92 is based on?

The military H-92 variant.
 
ThePointblank
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Re: Canadian C-148 Helicopter missing presumed crashed

Thu Jun 18, 2020 2:19 am

Interesting turn of events per what the Directorate of Flight Safety revealed in regards to the CH-148 crash:

http://www.rcaf-arc.forces.gc.ca/en/fli ... r/kae63jt8

During the return for recovery, the aircraft made a pass on the port side of the ship, from stern to bow. The aircraft then executed a left hand turn to establish a downwind leg in preparation for approach to the ship. Astern and inside the control zone of the ship, the aircraft commenced a final left turn to set-up for the approach. During this final complex manoeuvring turn to close with the ship, the aircraft did not respond as the crew would have anticipated. This event occurred at a low altitude, was unrecoverable and the aircraft entered a high energy descent and impacted the water astern the ship.


https://www.cbc.ca/news/politics/cyclon ... -1.5613239

After conducting a low flypast of HMCS Fredericton, the aircraft was turning under the semi-autonomous control of its fly-by-wire computer system when a software "bias" told the helicopter it wasn't moving fast enough.

The computer pitched the nose downward and sped the aircraft up. Investigators suggest the pilot may have tried to manually override the computer and pull up from what had become a swift, fatal dive into the ocean.


Basically, the air crew wanted the helicopter to do one thing, but the helicopter did another thing that was totally unexpected, and there wasn't enough time or altitude for the pilots to correct the issue. In short, some sort of a bias signal built up in pitch channel in Flight Director mode of the Flight Control Computer.

They were also able to repeat the exact scenario in the simulator, with the same results as well per the briefing. With that in mind, they felt confident enough to return to operations with the CH-148, but with enhanced training on the exact scenario involved.
 
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Aesma
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Re: Canadian C-148 Helicopter missing presumed crashed

Sun Jun 21, 2020 12:55 am

So they're saying this is normal behaviour ?

From the description it looks like MCAS...
New Technology is the name we give to stuff that doesn't work yet. Douglas Adams
 
ThePointblank
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Re: Canadian C-148 Helicopter missing presumed crashed

Sun Jun 21, 2020 9:11 am

Aesma wrote:
So they're saying this is normal behaviour ?

From the description it looks like MCAS...

The way that's being described to me is that the modes in which control input biases are applied, particularly in complex 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.

Definitely doesn't sound like a MCAS situation, just that the controls behaved in a way in which the pilot was not expecting, and did not notice until it was too late.

It very much sounds like a mismatch between what the pilot inputted as his controls and expected the helicopter to do, versus what the flight control laws in the helicopter were programmed to do. Listening to Col. John Alexander's presser, the accident occurred when the pilot made a pitch, yaw, and roll input as he was setting up for the final approach to HMCS Fredericton for landing. The helicopter was under automated flight director control (akin to a form of an autopilot) at the time.

Per what is being described, making adjustments to pitch, yaw, and roll while under flight director control was part of the certification process; however, there was a limit placed on how long inputs can be made by the pilot to overrule the flight director control before the flight director modes that coupled the the pitch and roll axis would determine that further automated adjustments was neither desired, or engaged.

In this instance, the flight director onboard Stalker-22 was set to hold a specific altitude and speed, there is a bias in the flight director in which the pitch and roll axis could offset the inputs of the pilot. The effects of the bias varies in magnitude based upon the amplitude and duration of the pilot's inputs applied while overriding the pitch and/or roll selection as set in the flight director. The amount of inputs made by the pilots was outside the aircraft's certification resulted in a pitch bias where the crew would be caught unaware as they would have never experienced it, nor exposure prior to this accident, and with no knowledge on how to handle the situation. Thus, the accident was unavoidable based upon their low altitude because they lacked the time to realize that the aircraft was not responding to their inputs, and manually correct for the issue.
 
mxaxai
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Re: Canadian C-148 Helicopter missing presumed crashed

Sun Jun 21, 2020 11:21 am

ThePointblank wrote:
Per what is being described, making adjustments to pitch, yaw, and roll while under flight director control was part of the certification process; however, there was a limit placed on how long inputs can be made by the pilot to overrule the flight director control before the flight director modes that coupled the the pitch and roll axis would determine that further automated adjustments was neither desired, or engaged.

In this instance, the flight director onboard Stalker-22 was set to hold a specific altitude and speed, there is a bias in the flight director in which the pitch and roll axis could offset the inputs of the pilot.

Trying to understand this in simple terms:
The helicopter was under autopilot control while the crew made manual inputs. Such manual inputs were part of regular operations to make minor corrections, but it was not expected to have both pilot and autopilot inputs for extended periods. So the autopilot started to apply a bias (trim the helicopter?) to counteract the manual input. When this bias became too large, the autopilot overrode the manual input and started a nose-dive that could not be recovered at this altitude.

So essentially, the pilot was fighting the autopilot, albeit without knowing the consequences. I guess for future operation the solution is to turn the autopilot off during complex maneuvers?
 
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Aesma
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Re: Canadian C-148 Helicopter missing presumed crashed

Sun Jun 21, 2020 5:30 pm

What about putting in an anti-crash law instead of allowing the helo to plunge to its demise ?
New Technology is the name we give to stuff that doesn't work yet. Douglas Adams
 
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AirlineCritic
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Re: Canadian C-148 Helicopter missing presumed crashed

Sun Jun 21, 2020 5:43 pm

It is a surprising control function to have. I understand it in some ways (e.g., aircraft pitching down instead of stalling) but this particular case didn't seem like there was a need the aircraft to do this. What was the control system trying to achieve?
 
ThePointblank
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Re: Canadian C-148 Helicopter missing presumed crashed

Mon Jun 22, 2020 4:19 am

Aesma wrote:
What about putting in an anti-crash law instead of allowing the helo to plunge to its demise ?

The helicopter's flight director was placed into a mode where it was supposed to maintain a certain altitude and speed. The CH-148 doesn't have a terrain following ability, so this isn't feasible, along with the fact that they were setting up for landing as they were on the final approach.

To me it sounds like the pilot was trying to do something that he would have been able to do in a Sea King, but the Cyclone isn't a Sea King in terms of how it handles and reacts. It's a totally different aircraft, and behaves differently to control inputs (or in the case of this, multiple control inputs).

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