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BRS... again?


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Marbleturtle,

Save your dime,I've already talked to them a few months ago about this subject.They are very concerned about the nose down attitude a canard would exhibit during a BRS deployment.They are not interested in researching this at the moment.

Joe Cygan

Cozy MKIV #1022

Southern California

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I'm still not convinced that a BRS will be an effective device, but I can't sit by and watch as bad arguments are thrown around.

 

First of all, no one is suggesting that a verticle decent at 15 - 30 ft a second is a great idea. A mostly horizonal path is always the best way to approach the ground. The only way I would deploy such a system is in an extreme situation which would prevent an emergency landing. A verticle decent is not a good idea... not at 15, 30, or 2 ft/sec. But it is PREFERABLE to a verticle decent of 300 ft/sec. I'll take 30 ft/sec nose up, nose down, inverted, in a cartwheel, on the moon, kids kicking the back seat all the way down, in a lake, day or night, whistling dixie in the middle of Oshkosh before belly flopping at at 200mph. Don't care if the aircraft survives or not. Building another sounds like fun and should only take half the time.

 

This argument might be a moot point anyway. I mentioned to my wife that the next time we go to Florida, she can leave at 5 AM and spend 10 hours in the minivan with the kids. Then she can pick me up at the airport after my comfortable 3 hour flight sans BRS.

 

I do believe the wind direction is changing. :D

This ain't rocket surgery!

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I was just reminded of something an old man I knew once said about building aircraft. He was dirty, unkempt, smelly, foul mouthed, and rude, but he built the most beautiful flying models.

 

He told me "Build a plane to survive a crash and it will. Crash, that is. Build it to FLY."

Evan Kisbey

Cozy Mk IV plans # 1114

"There may not be any stupid questions, but I've seen LOTS of curious idiots..."

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Very interesting debate on BRS systems. If I might add two cents worth I would suggest investigating parachute systems that form part of your seat back as in the military for multi-crew airplanes without ejection seats or even the back packs that we wear for aircraft that are ejection but not integrated into the seat. They would at the very least provide reassurance to scared pax even if maybe not much help.

 

The broken rip cord for the fake T handle is quite the innovation and seems to be a cheap easily engineered solution! Jobs at aircraft manufacturers await!

 

I have to agree with a number of the contributors, the engineering and evaluation would be quite the undertaking and require lots of $$$$. My preference would be to fly the aircraft in barring a disaster precluding that option.

 

We were always taught in the Canadian Air Force if you can't eject stay with the plane you have a much better chance of making a forced landing and surviving even under difficult circumstances.

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oh that solution, well I have that solution, our nose lift manual overide is in the center of the dash, a square drive socket sticking out, we will fabricate a large "PRESS IN EMERGENCY" button for aesthetics and passenger peace of mind.

 

Mike

maker wood dust and shavings - foam and fiberglass dust and one day a cozy will pop out, enjoying the build

 

i can be reached at

 

http://www.canardcommunity.com/

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  • 5 weeks later...

<... Silly Canadians ...>

In 13 years and nearly 4000 hrs tactical jets, I only ever HEARD of ONE guy who successfully bailed out of a tactical jet (this one was actually a supersonic fighter ... longish and pretty interesting story). At least a dozen or so have successfully ditched a tactical (but never a supersonic, IIRC) jet.

Not too encouraging either way .... Jim S.

...Destiny's Plaything...

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I agree BSR would be a lot of work to fit a canard. Was thinking that a deep stall recovery system, DSRS, would be of more use and a bit easier to design/fit a canard. Not that I'm questioning the canard design, but pilot loading and building errors, at least in my case, scares the hell out of me. Basically, you would have a small ballistic shut, maybe 1 to 2 square feet in size with a five foot line or so, located at each wing tip pointing aft. In case of a deep stall, activate the DSRS, which would provide just enough drag to point your nose earth bound and regain airspeed over the airfoils again. Once you’re assured of controllable flight, cut away the drag shuts and land. If the shuts could be sized correctly, you could leave them deployed and attempt a landing with some power add to over come the drag. That way if the deep stall condition was not correctable in flight you would have a second chance at recovery.

 

As Jim S. would say "just a theory"

 

Mark Logan # 793 with no money in plan bank. Donations anyone?

Thanks

Mark 793

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Hmmmm.

Interesting idea, but....

Deep stall doesnt worry me (or any of the canard pilots I know). The design is well proven, and the cg limits clearly established and tested. Any plane will fly like a pig, if at all, if you get the cg out of limits. Any pilot planning a take-off should be as aware of cg as he/she is of fuel status.

 

What would REALLY scare me is the potential for inadvertant deployment and/or partial failure of the DSRS system.

 

A simpler solution, if you really have a problem with this practically nonexistent issue, might be to always carry a 50lb lead weight in the back (while staying within cg limits). Now you have the ability to move this weight to the front to correct a cg problem. Of course, the weight would take up part of the back seat, so you probably couldnt accidentally get the cg out of limits anyway.:)

 

By the way.... building errors are not an issue here because you'll do you're own weight and balance calculations before first flight and correct any cg issues then.....unless, of course you count loosing a large amount of mass from the front, like maybe the canard. If this should happen, you're a lawn dart and deep stall is the least of you're worries.:P

I can be reached on the "other" forum http://canardaviationforum.dmt.net

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  • 4 weeks later...

Ok, I'm not sure if I am walking into a hornets nest, but here goes....

 

I think the arguments that the cozy is a proven design and has an excellent track record is very compelling evidence that you probably will never need to deploy a BRS because of an in-flight structural failure. Kudos to Burt and Nat, from what I have seen and read it's a very safe design.

 

But...The quest for a system that would bring an aircraft to the ground with a reasonably good chance for the pilot and passengers to survive is, in my opinion, a legitimate thing to look at. In my mind (not a big place), there are situations that pilots get themselves into that cannot be gotten out of. The fact is that pilots are human and make mistakes. I can't think of anyone that wants to or expects to spring a fuel leak over a rugged mountain range. Or intentionally finds themselves in a situation where they are above the clouds with no recourse other than to descend IFR down into severe terrain. Would anyone willingly take off in an aircraft with their wife and kids in the passenger seats if they knew that they were 45 minutes from their first heart attack, stroke, acute food poisoning, etc? Freak turbulence? Unanticipated severe Icing? Think these situations were avoidable? Yes of course, most of them are, but pilots still find themselves in these situations. I've spent the majority of my adult life dealing with and learning to deal with extremely dangerous situations and if there is one thing that has become apparent to me it is that highly qualified and prepared people can still make mistakes and or bear the brunt of Murphy’s law. I’ve lost several friends this way.

 

Now, that being said, would I use a BRS? Probably not, But I would love to see someone do it. Who knows, maybe the technology will come in to its own over the years. It would also give us a great deal to talk about :D.

 

Side note: I read the other day in Kitplanes about the Mystere S-45 pusher having a BRS on its underbelly. Here is a quote:

The main strap, made of Kevlar, is 25 feet long and encapsulated within the right side of the fuselage under one layer of fiberglass. The structure is locally reinforced, and the top layer zippers off in case of deployment. Kevlar is employed to ensure it will not be cut if it catches the propeller

The article also makes it sound as if there is only one main attach point located right above the CG. I’m not suggesting that, because it was done in this case, it would be wise or easy to do it in a Cozy however.

 

Anyway, just thought I would throw that out there for discussion.

 

Jake

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That's a well worded argument, Jake, and I agree that it would be nice to have a BRS System installed for those unlikely, but possible, eventualities.

 

Unfortunately we, as builders, have to balance risk against cost, inconvienience, and potential for further risk being introduced. We make those choices when we choose a type, an engine, etc. etc. etc. Most would fit a BRS in a minute, if it could be fitted in a minute, didnt cost $5k and was sure to work when needed, and - especially - not work when not needed.

 

Sometimes I think that the biggest risk is getting to the airport in the first place. In the case of BRS, my judgement at the moment is that the risk / inconvienience and cost outweight the potential for increased safety at this stage. We're all "risk takers" to some extent, and I suggest that most of us, when faced with a choice of deployment or trying to fly it down without damage, would take the latter choice. So - It's only in case of structural failure that I'd use it. This brings me back to the old argument about the design being solid and unlikely to fail.

 

Perhaps the argument for a BRS will get stronger over time, but not if no-one tries it (and needs it).

I can be reached on the "other" forum http://canardaviationforum.dmt.net

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My wife was with me when I went to see Greg Richters Cozy. He had a thought about the BRS subject that we both agreed with. The Cozy is not going to suffer a structural failure. If a problem happens in flight, the Cozy airframe can remain controllable at speeds as low as 55mph. At that speed its better to be able to choose a spot and inbound position to crash land (even if its in the trees or mountainside) than to end up droping down in a random location at 15-20mph verticle. He went on to mention someone he knew who had to put down in a swamp somewhere in South Ga. It worked out much like a car crash. The destruction of the wings, canard, and nose absorbed much of the energy of the crash. The pilot was cussing and ranting about his crash while being rescued from the swamp, but since he was buckled in properly, he was okay.

 

This makes sense to me. If a vortilongirudderaileron goes sailing off like a boomerang, I would be up a creek. If anything else goes wrong, just keep flying (gliding?) the plane! It all depends on the structure of the airframe being sound. I for one am confident it is.

This ain't rocket surgery!

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Originally posted by jw25wg

If I might add two cents worth I would suggest investigating parachute systems that form part of your seat back as in the military for multi-crew airplanes without ejection seats or even the back packs that we wear for aircraft that are ejection but not integrated into the seat. They would at the very least provide reassurance to scared pax even if maybe not much help.

I dunno, seeing a backpack parachute usually scares the bejeezus out of non-pilots or non-skydivers. I've yet to meet an aerophobe who climbs into an aircraft and says "Oh, goody, parachutes!" :)

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After reading this thread I thought I would mention an interesting implimentation.

 

http://www.internetage.com/cartercopters/writeups8.htm

 

Should take care of all the naysayers.

 

On the other hand there is a ROI issue. Far, far more problems happen with the fuel supply to the airplane than catastrophic flight controll issues. A simple one fuel tank, every drop of fuel useable, fully redundant fuel system would save more planes, underware and lives in 1 year than a BRS would in 100, I would guess.

 

But I could be wrong.

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Fuel is always the third largest problem, # 2 is flying foolishly, hello mr. chimney, etc and NUUUUUUUUUUUUUUUUUUUUUUUUUUUuuuuuuuuuuuuuuuuber 1 is always

 

Knowingly flying from good into BAD weather

maker wood dust and shavings - foam and fiberglass dust and one day a cozy will pop out, enjoying the build

 

i can be reached at

 

http://www.canardcommunity.com/

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Like I wrote earlier, it's these situations that a last resort back-up would be handy. I think John and many others make an excellent point that structural failure is the least likely scenario to cause an unrecoverable situation. You know much more about the airframe than I do by a factor of 1000 so I trust what you have to say in this regard, and the statistics for the Cozy bear this out as well. It's the situations that are out of my control, or I put myself into, that make a BRS somewhat of an attractive idea. Notice that most of these situations could be avoided with the proper planning and or due diligence, but we see time and time again that pilots (and any other professional) make poor decisions. For me to say that I would never make a poor decision would be irresponsible of me. It would be, in its own right, a lack of planning on my part. But, until this system is proven and tested more than it is, installing it may be just as much of a risk.

 

I looked at the Carter Copter BRS installation. The most interesting aspect of it to me was that it is designed to land tail first. This, in my opinion, would be the optimum way to impact. Depending on how your seats were designed (cushioning, head support, etc), I believe the human body would fare much better in this orientation. Anyway, I am by no means an expert, and most of this is because I like to discuss these sorts of things. :D

 

Jake

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Another way to look at this stuff might be to say that we're "guilding the lily" a bit, or as Jim S might say - "pole vaulting over rat turds".

 

I owned a Piper Cherokee for years, and have flown lots of hours in 172's and Archers. All these flight hours were completed successfully without the luxury of dual alternator, dual battery, BRS, terrain following GPS, etc. etc. At the time I felt quite safe. Now here I am, adding a second battery, making dual redundant fuel systems, adding voice and light annunciator warning systems and lusting after an EFIS One, all in the interests of "safety".

 

I wonder... how much safer will I really be? maybe 0.1% ???

 

As was said, the things that are likely to kill someone in an airplane (Cozy or 172) are well known -

 

1. VRF > IFR

2. Pilot error / stupidity

3. Lack of Fuel

 

Structural failure is soooooooo far down the list that it hardly deserves mention. Anyone seriously considering a BRS would probably have 10 times more impact on their overall safety by spending the $5k on additional training to help them avoid items 1 thru 3 on the list.

 

But then again, in the interests of perpetuating a pointless but interesting discussion.... :D

 

One approach to the whole problem might be a ejectable pilot compartment. Once the pax compartment is seperated from the plane with explosive bolts or something, then the parachute deployment is trivial. What's the point of protecting the whole plane - it's scrap anyway. All we're trying to save is the people.

 

Just so long as the explosive bolts don't fire off accidentally while you're landing at Sun & Fun in front of 20,000 fellow pilots. :(

I can be reached on the "other" forum http://canardaviationforum.dmt.net

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... explosive bolts?!?!?! Yikes! I'd rather go with the kevlar straps under a layer of glass and a balistic parachute.

 

Although I do remember the trepidation airbags in cars caused because people were afraid they would deploy when the car hit a hard bump. I don't think anyone would argue that the effect of airbags has been positive.

This ain't rocket surgery!

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