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FlyingMonkey

GRS Parachute Failure

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Wow, that is surprising given that GRS are equipped on all Sting aircraft and several other makes as well.  If I had one I'd be questioning the reliability of the system.  Makes me happy we have a BRS.

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I would call this a GRS installation failure versus a chute failure.  The chute failed to fully inflate when the "single front attachment point detached".   Could be the attachment point was at fault.  Current requirements are for two attachment points.

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Just now, S3flyer said:

I would call this a GRS installation failure versus a chute failure.  The chute failed to fully inflate when the "single front attachment point detached".   Could be the attachment point was at fault.  Current requirements are for two attachment points.

Agreed, but at this point we don't know if the installation was per manufacturer's guidance or not.  In any event, if this is really the first use in flight, it's a 100% failure rate.  If I had a GRS that would not inspire confidence.

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If he was in a spin when it was pulled, it would have put an ENORMOUS strain on one attachment point anyways as the aircraft goes around the axis of rotation. I wouldn't fault GRS if that's the case.

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An event like this is something none of us want to see happen.   It isn't known if the victims were aware that the newer GRS systems had two anchor points and if they would have known about the upgrade to the newer 'chutes, there were no failures to tell them their single anchor system was not safe.    I'm thinking that there's a very good reason for GRS upgrading their 'chutes to a two anchor system and that the lawyers will want to understand why GRS' added this.  FWIW, I would think the design of these systems would allow for failure of the canopy to occur before failure of the attaching straps and anchors.

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4 hours ago, Anticept said:

If he was in a spin when it was pulled, it would have put an ENORMOUS strain on one attachment point anyways as the aircraft goes around the axis of rotation. I wouldn't fault GRS if that's the case.

Cirrus lists the BRS as the only approved method of spin recovery.  One of the classic scenarios for a deployment of a chute is an unrecoverable spin.  If the GRS cannot function in that scenario, it’s a serious deficiency IMO.

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46 minutes ago, FlyingMonkey said:

Cirrus lists the BRS as the only approved method of spin recovery.  One of the classic scenarios for a deployment of a chute is an unrecoverable spin.  If the GRS cannot function in that scenario, it’s a serious deficiency IMO.

Will the BRS save the Cirrus once the spin has developed?  Could this issue be the reason that Cirrus places some much emphasis on pulling early?

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45 minutes ago, Ed Cesnalis said:

Will the BRS save the Cirrus once the spin has developed?  Could this issue be the reason that Cirrus places some much emphasis on pulling early?

It is designed to, yes.  the use of the parachute in a fully developed spin is mandated in the POH, and the inclusion of the BRS was used by Cirrus as a method of "alternate compliance" with the spin requirements for certified airplanes.  

I don't know why a parachute system would have trouble in a spin, the chute and all components are spinning at the same rate as the airplane, it's not like the parachute is fixed to some point in space and the airplane is spinning around to twist the lines.

The "pull early" mantra is used to get the pilots to pull *at all*, since training has shown that until proper instruction is given, pilots are likely to not pull at all or until it's too late.  Fast Eddie mentioned this is exactly what happened to him in the sim. 

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FYI -- there have been several successful GRS deployments with one rather impressive one caught on video at a low altitude:

 

Sportpilottalk has a couple more.  Google Pipstrel GRS deployment for more.

I'm guessing the quote in the article meant to state that the chute deployment referenced was the first failure.

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2 minutes ago, S3flyer said:

 

I'm guessing the quote in the article meant to state that the chute deployment referenced was the first failure.

Must have been, thanks.  I know there are a lot of GRS out there, seems weird this would be the first use.  

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On 11/3/2017 at 9:02 AM, FlyingMonkey said:

I have not seen a ballistic chute failure before, but here it is.

 

https://www.avweb.com/avwebflash/news/Chute-Failure-Cited-In-Fatal-Crash-229857-1.html

I''m guessing it's the first time a chute had been pulled on this specific aircraft.  Galaxy has videos on their web page of chute pulls.

 

https://www.galaxysky.cz/rescue-aircraft-s106-en

EDIT:  Whoops just noticed S3flyer is way ahead of me.  Pays to read the whole thread before posting!

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This video is instructive. I assume the BRS in our CTs works similarly.

Prior to deployment the aircraft is in forward flight, with its weight on its wings, at an altitude of perhaps 200 feet. The chute deploys directly behind the aircraft. Forward flight ends abruptly. The plane stalls... and falls. It accelerates quickly with the nose aimed straight down at one point and very little vertical restraint from the chute as it swings from a position in front of the chute to underneath it. It takes time for the chute to subsequently decelerate and stabilize the plane. In fact, though there was no injury here, it looks like from a slightly lower altitude there certainly would have been. The chute manufacturer points out that he is below the safe deployment altitude. 

Yet my CT manual says: "In an emergency, the parachute system should be activated even if at a very low altitude." I guess it's a question of the nature of the emergency. If its catastrophic, you might as well pull even at 100 feet, though I wouldn't necessarily expect a better outcome.

Certainly the guy in this video, who used the chute out of concern over the integrity of his nose gear, should have pulled from at least a couple hundred feet higher... if at all. Even flipping over on landing would have been less traumatic than this. And there is always the potential for the parachute to fail to open completely. A streamer, in jumper parlance, with no way to cut away would be the worst of all worlds.

Mike Koerner

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Hey Mike,

The situation in the video to me seems "quirky".  I can't really figure out why the pilot pulled the parachute for a nose wheel problem, especially since the runway was grass; I'd have probably tried to land it.  That aside, the airplane was going really slowly, with full flaps.  you can see the airplane start to pitch up *before* the chute is deployed; I think the airplane was already stalling and in the midst of dropping the nose as the deployment happened.  I think a higher speed deployment would have looked quite different.

As has been discussed on this forum quite a bit, it seems that faster speeds equal quicker deployment of the parachute.  It seems to take a few seconds for the parachute to inflate in that video, and I think that is largely due to the low speed of the airplane at time of deployment.  I think if he'd have been going 80 or 100 knots it would have been a quicker and more positive deployment with less "hang time".

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I don't think the size matters vs the descent rate.  I did a little digging and the LSA chute data is:

GRS - canopy area: 115 sq meters, descent rate 23.5 ft/sec (http://www.galaxysky.cz/technical-data-s26-en)

BRS - canopy area: 109 sq meters, descent rate 21-25 ft/sec (https://cafe.foundation/v2/pdf_tech/Vehicle.Parachutes/BRS-6_General_Installation_Guide.pdf)

 

 

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