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Minimum altitude required to pull parachute?


bmar

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It is hard to say what the minimum is because there are so many factors such as speed and attitude. At one time I had an email that suggested that there could be benefits to pulling the chute as low as 165 feet. If something happens below 500 feet and I think I need the chute I am going to pull the handle regardless of altitude. If something happens when I am higher I will certainly pull before I get to 500 feet.

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Their should be a set minimum safe altitude to pull. Did you see the recent cirrus crash in California, he pulled the shoot at an altitude of several hundred feet and witnesses said it cause the tail to lift and the nose to point down and he hit the ground hard nose first. Under a certain altitude the chute is not safe to pull and you need to fly the plane. 

 

Im surprised flight design doesn't have a specific altitude for the chute pull? It has to be listed somewhere 

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IIRC there was a successful BRS deployment in Morocco at ~60ft during a botched go-around.  If you need the parachute, I would not worry too much about altitude or airspeed, I would just pull it.  If things are that far gone, it's extremely unlikely to worsen the situation.

 

 

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19 minutes ago, FlyingMonkey said:

IIRC there was a successful BRS deployment in Morocco at ~60ft during a botched go-around.  If you need the parachute, I would not worry too much about altitude or airspeed, I would just pull it.  If things are that far gone, it's extremely unlikely to worsen the situation.

 

 

+1.  If you've got it, use it.

I'm sure there's plenty of altitudes listed for use, and probably there's some reason (e.g. lawyers) for stating a minimum altitude to deploy.  But those people won't be up in the air with you when (touch wood) you have an issue.  And if they were, I'd bet they'd rip that red handle out of the bulkhead or panel to get it to deploy.  :P

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1 hour ago, bmar said:

Their should be a set minimum safe altitude to pull. Did you see the recent cirrus crash in California, he pulled the shoot at an altitude of several hundred feet and witnesses said it cause the tail to lift and the nose to point down and he hit the ground hard nose first. Under a certain altitude the chute is not safe to pull and you need to fly the plane. 

 

Im surprised flight design doesn't have a specific altitude for the chute pull? It has to be listed somewhere 

What if the airplane is not flyable? The "something" I referred to in my post would likely mean the airplane is likely not flyable.

As for altitude I don't think Flight Design has done the extensive flight testing of the parachute like Cirrus has. Without the testing it is hard to come up with a number.

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1 hour ago, Tom Baker said:

What if the airplane is not flyable? The "something" I referred to in my post would likely mean the airplane is likely not flyable.

As for altitude I don't think Flight Design has done the extensive flight testing of the parachute like Cirrus has. Without the testing it is hard to come up with a number.

I am referring to a flyable airplane. Any airplane that is uncontrollable you would absolutely pull the chute at any levels. 

Im more concerned with low altitude engine outs etc, and if you study the cirrus caps deployments, low altitude parachute deployments of a flyable aircraft has actually killed pilots by the plane stalling and diving towards the ground when the parachute is first deployed.

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2 hours ago, bmar said:

I am referring to a flyable airplane. Any airplane that is uncontrollable you would absolutely pull the chute at any levels. 

Im more concerned with low altitude engine outs etc, and if you study the cirrus caps deployments, low altitude parachute deployments of a flyable aircraft has actually killed pilots by the plane stalling and diving towards the ground when the parachute is first deployed.

So if the airplane is flyable, but you are at low altitude and have no good landing option, how is the parachute going to make it worse?  Even if it pitches you downward, it's acting as a giant air brake at least, lessening the impact energy.  I just don't think there is a hard, one-size-fits-all altitude number that works in all cases.  50ft might be plenty in one case and 500ft not enough in another.    

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I believe demonstrated was 600 feet, and it becomes uncertain after that in a CT. The issue to worry about is the chute won't unreef quickly enough.

That said, nobody is going to put their neck out and say anything official. I'm pretty sure BRS would rather you pull sooner than later, and putting out an official safe altitude number might encourage people to wait *longer* before pulling.

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On ‎8‎/‎3‎/‎2017 at 8:54 PM, FlyingMonkey said:

So if the airplane is flyable, but you are at low altitude and have no good landing option, how is the parachute going to make it worse?  Even if it pitches you downward, it's acting as a giant air brake at least, lessening the impact energy.  I just don't think there is a hard, one-size-fits-all altitude number that works in all cases.  50ft might be plenty in one case and 500ft not enough in another.    

While not exactly the same dynamics between the CT and Cirrus, Cirrus and the owner group has done a tremendous amount of research and analysis on this.  Their general consensus is not to pull under 500 feet if under control, and they as a group are pretty "pro-pull," more so than what I've observed with CT owners. 

I agree with Tom Baker, in that if there's a major problem making the plane uncontrollable, then there would be little to lose by pulling the chute at a low altitude.  However, if the plane is controllable, and it was under 500 feet, I'd try to land the plane, keeping it under control at the slowest possible speed.  Assuming the Cirrus decision process is correct (no guarantee this is the case, of course) then with the very low stall speed of the CT, I believe that the risk of an abrupt nose-down attitude with the deployment of the chute would be higher than the risk of a low-speed controlled landing, even in unhospitable terrain.

Andy

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There have been saved as low as 100' depending on the weight of the plane. A light plane like a CT has a far better chance than a Cirrus or heavier plane. Larger chutes have longer cords. Then you need more altitude to get cord stretch and at least slow you down some. You may tag the ground at a swingt, but far slow enough to walk away.

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12 hours ago, andyb said:

However, if the plane is controllable, and it was under 500 feet, I'd try to land the plane, keeping it under control at the slowest possible speed.  Assuming the Cirrus decision process is correct (no guarantee this is the case, of course) then with the very low stall speed of the CT, I believe that the risk of an abrupt nose-down attitude with the deployment of the chute would be higher than the risk of a low-speed controlled landing, even in unhospitable terrain.

Andy

This comes back to what I said above, that circumstances have to dictate.  If I'm at 400ft over a nice flat field, sure I'll try to land.  If I'm 400ft (or 300ft, or 200ft) over a jagged boulder field, I'll take the chute over a 45kt impact into large rocks every time.  The fact is that chute deployments have a much higher survival rate than off airport landings, even in good circumstances.  I'm not sure there is enough data to show that low deployment height changes that situation.

After all, the chute takes how long to fully deploy...3-5 seconds?  At 400ft in a CT you can probably glide another 30 seconds at least.

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Just now, Ed Cesnalis said:

Unless it isn't / doesn't.  Sink rate is a big issue.  Pull at low altitude with rapid sink, consider flying it to the crash otherwise.

Well, the question was a situation with the airplane under control.  To me that means gliding, not in a full stall and falling out of the sky! :)   But point taken.  

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12 minutes ago, FlyingMonkey said:

Well, the question was a situation with the airplane under control.  To me that means gliding, not in a full stall and falling out of the sky! :)   But point taken.  

We are on the same page but you can be under control with a high sink rate or under control at best glide.

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1 hour ago, Ed Cesnalis said:

We are on the same page but you can be under control with a high sink rate or under control at best glide.

Agree totally.  I know Roger has said the chute deploys faster at higher speed, so that could be a factor in any given situation as well; a slow forward speed and high sink rate might make for a slow deployment.

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