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-   -   Parachute Recovery System (https://www.pprune.org/rotorheads/502922-parachute-recovery-system.html)

n6330v 14th Dec 2012 17:58

Parachute Recovery System
Hello everyone. I'm very green to the PPRUNE network and am trying to do a little research for a class project. I am very appreciative of any and all replies.

My assignment is to develop a system that parallels the BRS system in Cirrus aircraft for rotary wing platforms. This system should be designed as a final contingency in case of structural failure or a failed auto.

For the time being, I am looking at a configuration that detaches the main blades, a la Ka-52 style, in order to allow for main fuselage recovery in any and all attitudes.

I would really like to hear what you guys think about the following...

1) What would be some of the challenges facing such a system from a technical perspective?
2) Would such a system be viable in the commercial sphere (obviously after much red tape certification wise)?
3) Do you think the growing UAV market, especially considering the growth in rotary wing UAVs, would have interest in something like this?

Thank you all in advance for the information!

hillberg 14th Dec 2012 19:37

AUTOROTATION :eek:, How would you feel about getting rained on by some bits & pieces of a helicopter?:=
Run through by a falling blade,:{
or the chute wrapped around the whats left as a low orbit asteroid.:ugh:
Been tried in the 1950s. weight, added parts, high risk, Dropped.:rolleyes:

n6330v 14th Dec 2012 19:49


Thank you for the reply. What if, theoretically, one were able to descend each blade individually in order guarantee low risk to property and personnel on the ground?

SilsoeSid 14th Dec 2012 21:06

Losing...will......to ............. :zzz:

Ascend Charlie 14th Dec 2012 21:14

Sure this isn't Sheronfrd under a new name?

Lonewolf_50 14th Dec 2012 21:45


The failed auto piece of your problem statement is a training issue, not an engineering issue.

The "blades that blow off" induces a flying problem: this problem arises as an operational failure when pilots won't enter your aircraft to fly in it.

Beyond that, best wishes on your project.

topendtorque 14th Dec 2012 22:36

I'll have a go at it - Xmas an' all.
cheers tet.

3) Do you think the growing UAV market, especially considering the growth in rotary wing UAVs, would have interest in something like this?
1) No, there are no lives to save on a UAV
2) UAV's by their nature usually spy on the enemy, should one fail then killing as many as possible at ground contact would be a good idea.
3) UAV's usually possess cutting edge technology (read secret) therefore explosives on board is an excellent idea, but not to save the ship; Also refer item 2.

2) Would such a system be viable in the commercial sphere (obviously after much red tape certification wise)?
1) It's hard enough to design and build for viability without expensive addons,
2) The testing regime expense would be prohibitive as it would need to be tested so exhaustively that somehow a sane pilot might accept it.
3) The cost of buying explosives, securing it on the machine and presumably routinely replacing it when it becomes soggy and unstable would be prohibitive - so many constraints these days brought about by people of dubious nature trying get their hands on it for nasty reasons.

1) What would be some of the challenges facing such a system from a technical perspective?
1) The only time most helicopters are stable is during auto rotation and at termination simple control manipulation allows a soft touchdown, as do parachutes or so I am told. So, why dispense with one proven system to rely upon another which might or might not function,

2) Many pilots, if they entered such a flying vehicle, are already past masters at destroying machinery. To give them a nice explosive to do it better I think would be preposterous to any insurance company

3) Remember the adage of Santa Claus's check flight. Ol' check pilot whilst brandishing a 12 gauge says that he may fail one engine on take off. Result - engine refuse to start.Many helicopter engines are already hard to start with serious personality problems of their own.

n6330v 14th Dec 2012 23:52

Thank you all for the replies! As discouraging as some of them might be, I need to keep chugging along for the sake of the assignment.

From what I understand, it would very, if not impossible, for a pilot to accept such a system unless it has been tested through and through - and even then, it's still somewhat illogical.

I should have been more specific when talking about UAVs. I was specifically talking about civil/private operations (obviously outside of the con US for now). Do you think that, considering the lack of a pilot and the high interest in limiting damage to a high value asset, commercial entities might be interested in something that allows for a last resort?

lelebebbel 15th Dec 2012 01:28

I can actually see this being of some interest for UAVs, not so much for manned helicopters for the reasons stated above.

Many of UAVs do not have a way to land after a mechanical failure, even if it is just a "simple" engine failure (example, all the quad- and octocopters out there). They are getting bigger and heavier every day, and they are being used, legally or not, over populated areas. A ballistic chute would probably not be a bad idea. Here is a good example why:

As an added plus, you wouldn't even have to blow up the rotors prior to deploying it.

As for your original assignment, there is a Russian attack helicopter that has ejection seats, including the exploding rotor.
Kamov Ka-50 - Wikipedia, the free encyclopedia

n6330v 15th Dec 2012 01:59

How would you deploy a main fuselage canopy without blowing the rotors? Sure it would work in a flat and level attitude but if you have a roll or any type of unusual attitude I feel like blowing the main blades would be a must.

topendtorque 15th Dec 2012 04:30

Actually it would be quite simple. In a R22 flown remotely as a UAV one would simply leave the collective lever up after the engine stopped and in few seconds the M/R would stop turning, fail and flail. That's when the chute automatically opens via a switch which is a mercury resisted steel ball in a vertical tube which rushes to one end because of the sudden acceleration downwards.(Same switch as in earlier Emergency Locator Transmitters.)

Understand that in a 'manned' helicopter, it would need a mechanical "switch" because of the rank insanity of a pilot who tried this stunt would logically be unable to "switch" anything with that rush of blood to his head or the existing vacuum there most times, take your pick..

Reminds me of an experiment that a doctor of the brain (psychologist) was undertaking quite some years ago. It was written up in a Bulletin magazine, an Australian old mag, now defunct. His study was to examine the psychological factors that influenced people to jump out of fully serviceable aeroplanes, parachutists.

His method of study, take a parachute course. I still wonder after all this time how he sought credibility from his normal thinking peers for his paper.

Mind you the drivel that abounds in so called peer reviewed global warming articles should be enough to convince me of selected or deliberate lack of accountability in the scientific world...

merry Xmas

Non-PC Plod 15th Dec 2012 08:06

N6330V (catchy handle!) - you describe the circumstances where you can see this system as being of potential use - essentially structural failure. The problem is you will add definite weight and costs to the aircraft in return for protection from an extremely low probability event. In addition, you have to ask yourself whether a pilot is going to be able to push the button to deploy your system if the catastrophic event (eg blade separation or tail boom failure) occurred. I guess that is something which is impossible to prove, and therefore unlikely to attract a "buy-in" from helicopter operators.
Good luck with your assignment though!

lelebebbel 15th Dec 2012 08:45

How would you deploy a main fuselage canopy without blowing the rotors? Sure it would work in a flat and level attitude but if you have a roll or any type of unusual attitude I feel like blowing the main blades would be a must.
I am talking about a quad rotor UAV. The chute could simply be installed in the middle of the 4 rotors.

hillberg 15th Dec 2012 18:20

Toys doing a man work.:= Look back into history.:rolleyes:
You will see why chutes are not needed, As for the UAV hitting the building? Damn funny, :ugh:You better study what winds are doing around structures, Dumb ideas looking for a place to grow into STUPID ideas.:}

Flying Dutchy 15th Dec 2012 21:28

check this out:
"The long-life airframes have been engineered for robust operations and feature a raft of cutting edge technologies. These include an all-new primary fly-by-wire control system, a distinctive ejectable crew and passenger safety capsule cabin, and a telemetry downlink maintenance monitoring system," said Quest Helicopters.


Heliplane 15th Dec 2012 21:39

As we're talking hypothetically here, who ever said you would need to come down upright?

How about somehow inverting the otherwise stricken aircraft and firing the chute from the bottom?

Ceiling airbags in the cockpit/cabin could give occupants a level of protection and perhaps some kind of foam or other fire suppressant could be discharged into the engine/fuel areas to lessen the risk of a fire on impact.

Similarly, some form of external airbag - like pop out floats - could also soften the impact from the outside.

Inverting the aircraft so the chute can be fired upwards would clearly require some height but I'd imagine the technology used in ejector seats might have some use here. I believe even the Cirrus system has a relatively high minimum height for use.

The blades would stay attached but any energy left in them would be absorbed by the ground just before the fuselage hit the ground.

Ascend Charlie 16th Dec 2012 01:09

... and as the rapidly inverting fuselage met the still-in-plane rotating blades, there is a loud (but not totally unexpected) banging noise as the tailboom, the skids, and the partially-inflated parachute get severed by the blades.
System drops from sky inverted, saving the cost of burial.:(

n6330v 16th Dec 2012 07:49

Thank you all, once again for the replies. This has turned in to an interesting aggregation of information.

I've done some further research and have found that a system like this would be very beneficial for the UAV market (muti-rotor and conventional). The system I've designed with the help of some much smarter friends takes advantage of some cutting edge, yet proven concepts.

We concluded after quite a bit of digging around, that the most applicable method would be blade ejection (as twisted as that might sound especially after the aforementioned wheels analogy). Blade ejection turned out to be incredibly simple, especially on the UAV scale and utilizes bolts with a very long utility lifespan, non-active explosives, and quite incredible shear force tolerances.

The bolts, although explosive, are passive and we've designed a multi-layer electrical trigger system that completely segregates them up to a millisecond before system trigger.

The primary reason we reached an accord on blade ejection is the omni-attitude and motion ability of the designed system. Once the blades are detached, the rest is fairly simple and main fuselage/system recovery is through a conventional ballistics system.

As far as the blades being a hazard once detached...we designed and computer tested a system that utilizes individual recovery for each blade. As complex as that might sound, it's actually idiotically simple (to my surprise).

I welcome any further feedback but for now we're quite set in the design/concept. We're still doing quite a bit of research to try to account for unforeseen scenarios so I'll let you know, if anyone's interested, if anything changes.

Once again, thank you all for the information/opinions.

hillberg 16th Dec 2012 20:40

You deploy the chute and float softly down and see the Hi Voltage sub station below , Fried like a giant bug zapper!:D

UAV has a proplem, You bend down to see what's up. Up it is :rolleyes:the balistic charge launches the chute pilot , The police is saved the trouble of covering the body. :ouch:

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