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Puchaz spin - now wearing 'chutes



 
 
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  #21  
Old February 11th 04, 06:23 PM
Bill Daniels
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"Jim Harper" wrote in message
om...
Mike Borgelt wrote in message

. ..

some snippage
The whole ship chute concept is a bit of a worry. There you are in a
large heavy object with absolutely no control. With a personal chute
you do have steering on most rigs nowadays.

With a whole ship chute would it just ruin your day to have save and
then hit the high voltage lines, fall out of a tree, fall over a cliff
etc?

some MORE snippage

Mike Borgelt


Actually, Mike, on that we disagree.

Unless you are using a square canopy for your personal chute, you have
very little choice on where you are gonna land...and hitting the tree,
high voltage lines or over the cliff are gonna suck less if you have
some aluminum or fiberglass around you. Well, that was my decision for
sure.

Oh, and keep in mind that as I disagree with you, I do it with all due
deference to someone as distinguished in our sport as yourself (no
sarcasm, I meant that!)

Jim


OK, crank these numbers. Consider my Nimbus 2C (Experimental, so I could
install a BRS) at 650 Kilos with water (which takes 5 minutes to dump). The
gear strut will give 30mm on impact and the tire will give 50mm more. The
cockpit shell is just fiberglass with no crush structure.

I pop a BRS at 300 meters AGL with the surface wind at 15 knots. What are
my chances? Give BRS weights, 'chute diameters and descent rates.

Bill Daniels


  #22  
Old February 11th 04, 06:35 PM
Eric Greenwell
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Dave Houlton wrote:
This parachute discussion has me thinking about the rocket-deployed
chutes we used to have for hang gliding, and the BRS systems now in
Cirrus (Cirrii?) and small Cessnas. Probably no improvement w.r.t
weight or cost considerations, but for convenience, comfort, and "always
there when you need it" they would seem ideal. I don't actually know
the repack requirements, but I would guess they're annually or even longer.

Are there any gliders out there today with whole-ship BRS-type chutes?


Some of the Russia AC-4 gliders in the US are equipped with them, and
the SparrowHawk has it available as a $2200 option. At least one
SparrowHawk has it installed. Neither the Russia nor the SparrowHawk
people have tested the BRS in a glider yet.

--
-----
change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

  #23  
Old February 11th 04, 07:25 PM
nafod40
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Bill Daniels wrote:

I pop a BRS at 300 meters AGL with the surface wind at 15 knots. What are
my chances? Give BRS weights, 'chute diameters and descent rates.


Infinitely better than trying to bailout, no?

  #24  
Old February 11th 04, 08:23 PM
Dave Houlton
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Bill Daniels wrote:
"Jim Harper" wrote in message
om...

Mike Borgelt wrote in message


. ..

some snippage

The whole ship chute concept is a bit of a worry. There you are in a
large heavy object with absolutely no control. With a personal chute
you do have steering on most rigs nowadays.

With a whole ship chute would it just ruin your day to have save and
then hit the high voltage lines, fall out of a tree, fall over a cliff
etc?


some MORE snippage

Mike Borgelt


Actually, Mike, on that we disagree.

Unless you are using a square canopy for your personal chute, you have
very little choice on where you are gonna land...and hitting the tree,
high voltage lines or over the cliff are gonna suck less if you have
some aluminum or fiberglass around you. Well, that was my decision for
sure.

Oh, and keep in mind that as I disagree with you, I do it with all due
deference to someone as distinguished in our sport as yourself (no
sarcasm, I meant that!)

Jim



OK, crank these numbers. Consider my Nimbus 2C (Experimental, so I could
install a BRS) at 650 Kilos with water (which takes 5 minutes to dump). The
gear strut will give 30mm on impact and the tire will give 50mm more. The
cockpit shell is just fiberglass with no crush structure.

I pop a BRS at 300 meters AGL with the surface wind at 15 knots. What are
my chances? Give BRS weights, 'chute diameters and descent rates.

Bill Daniels


Hi, Bill.

Too many variables there to calculate for me, but I did visit the BRS
site to gather some data. Their 680 kg. capacity system is 13.5m in
diameter, weighs 16kg, and claims 7.6 m/sec descent rate @ 5000' density
altitude. So in your proposed situation you're going to land with about
a 15kt vertical component and a 15kt horizontal component. Translating
that into G-forces and survivability I'll leave up to someone more
knowledgeable...

OTOH, I'm glad you picked this particular scenario, because I think its
exactly where a BRS system would be invaluable. You're at 300m AGL in
an unlandable ship - you pull the BRS handle and 2-3 seconds later you
are under canopy. In the same situation what are your chances of
popping the canopy, unbuckling, bailing, and deploying your chute in
time? Now what if you're spinning, tumbling, or pointed straight down
without an elevator?

At a sufficient altitude where egress time isn't a big factor, I think
the personal vs. BRS calculation could go either way. The closer you
are to the terrain at the time of the 'incident', the more a BRS system
looks like the only game in town.

All IMHO,

Dave Houlton




  #25  
Old February 11th 04, 09:06 PM
Dave Houlton
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Jim Harper wrote:

Dave Houlton wrote in message ...


Are there any gliders out there today with whole-ship BRS-type chutes?

Dave



Hi, Dave.

The short answer to your question is, yep!
http://www.soaridaho.com/Schreder/HP...S_in_HP-16.htm

You can do a google search and find a long discussion regarding this
(initiated by me, that time...not the first discussion on this) from
around last Christmas (02).

Short form: I made the decision to put a BRS 1050 in my HP-16 because:

1. I am a big guy. Whilst I did fit in the glider with a parachute,
the ergonomics were challenging. Without a parachute, I am in
sumptious luxury.

2. I could. The glider is experimental, and changes are trivial. A
certificated glider would be much more difficult to do this in,
requiring a 337 which may or may not be possible (I'd bet on not).

3. While the cost was higher than a regular parachute (around $2500,
if memory serves, now around $2900) the weight penalty was not
significantly higher at 24 pounds for the 1050 softpack model I
bought. Repacks are sort of a push, given that they are quite
expensive, but only need done every 6 years.

I reached the decision after doing a moderately exhaustive search on
parachute saves in gliders. Basically, it looked to me like most
fatalities would not have been prevented by the usual open the canopy
and bail out...given the relative low altitude of most. Read the
thread for more on that, please. At any rate, I feel I can get a
canopy over me at anything above around 250 feet, perhaps lower, so I
have a better margin of safety than if I needed to open the canopy and
bail out...I think most believe that you need to start that at around
1500-2000 feet above ground.

I believe that my parachute will lower me relatively nose-down, and as
such, my legs will protect me to some extent on landing. I feel safer
surrounded by the aluminum and plexiglass than if I were on my own
under canopy, given that I'll likley not be descending into a prepared
drop zone, more likely trees or worse...and I have around 500 sport
parachute and military jumps, so I speak from knowledge there.

No, thank God, I have not had the opportunity to use it, and hope that
I never find out if it'll work...but it comforts me to know it's
there.

I hope that helps.

Jim


It does help - thanks, Jim! I'm flying club gliders now, but I expect
I'll eventually be an owner - and based on this discussion I'll quite
likely opt for an experimental. It just makes sense to me that if
you're trying to leave yourself an out for when things go Really Bad,
you want that out to be usable in as many phases of flight as possible -
including low on tow or in the pattern. BRS seems like the only game in
town in those situations.

I never put on a chute at all during training (including full-turn
spins, of course), but I started thinking more about it this fall when I
took my 8-yr-old son for his first glider ride. Along the lines of "I
should grab us some parachutes. But I'm not confident he'd be able to
get out and deploy, and I'm obviously not leaving without him...
Anyway, this is just a pattern tow and a sled ride - we'll never be high
enough to use them anyway." Perfectly reasoned but not very reassuring.

Dave Houlton
  #26  
Old February 11th 04, 09:11 PM
Bill Daniels
external usenet poster
 
Posts: n/a
Default


"Dave Houlton" wrote in message
...

OK, crank these numbers. Consider my Nimbus 2C (Experimental, so I

could
install a BRS) at 650 Kilos with water (which takes 5 minutes to dump).

The
gear strut will give 30mm on impact and the tire will give 50mm more.

The
cockpit shell is just fiberglass with no crush structure.

I pop a BRS at 300 meters AGL with the surface wind at 15 knots. What

are
my chances? Give BRS weights, 'chute diameters and descent rates.

Bill Daniels


Hi, Bill.

Too many variables there to calculate for me, but I did visit the BRS
site to gather some data. Their 680 kg. capacity system is 13.5m in
diameter, weighs 16kg, and claims 7.6 m/sec descent rate @ 5000' density
altitude. So in your proposed situation you're going to land with about
a 15kt vertical component and a 15kt horizontal component. Translating
that into G-forces and survivability I'll leave up to someone more
knowledgeable...


Dave Houlton


OK, Dave, good numbers.

This asks me to add 16 Kilo's (35 pounds) to the non-flying parts of the
glider for which I get a 15 knot descent rate when deployed (Maybe less
since I will be dumping ballast like crazy.) With a 15 knot wind I would
probably whack an obstacle at 20 knots. (Probably survivable - with
injuries.)

BTW, if I'm getting dragged by an open 'chute in that 15 knot wind, how do I
dump the 'chute?

I seem to recall that the price of this system is about $3500 - presumably
not installed. What would be the installed price?

Bill Daniels

  #27  
Old February 11th 04, 09:29 PM
Mike Borgelt
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Posts: n/a
Default

On 11 Feb 2004 08:50:00 -0800, (Jim Harper) wrote:

Mike Borgelt wrote in message . ..

some snippage
The whole ship chute concept is a bit of a worry. There you are in a
large heavy object with absolutely no control. With a personal chute
you do have steering on most rigs nowadays.

With a whole ship chute would it just ruin your day to have save and
then hit the high voltage lines, fall out of a tree, fall over a cliff
etc?

some MORE snippage

Mike Borgelt


Actually, Mike, on that we disagree.

Unless you are using a square canopy for your personal chute, you have
very little choice on where you are gonna land...and hitting the tree,
high voltage lines or over the cliff are gonna suck less if you have
some aluminum or fiberglass around you. Well, that was my decision for
sure.

Oh, and keep in mind that as I disagree with you, I do it with all due
deference to someone as distinguished in our sport as yourself (no
sarcasm, I meant that!)

Jim



I figure that the choice with a personal chute is small but with a
whole ship chute it is zero.

The guy who taught me to pack a chute gave me escape instructions from
the glider and then said "enjoy the ride" as you were likely to be
confused and shocked anyway. He wouldn't have been as his real job not
long before had been giving the Viet Cong a hard time as a member of
the Australian SAS.

The other problem with whole ship chutes is that there is no room for
them - the engine occupies that space!

I once saw a movie of the BRS drop test on a C150 simulating its
arrival under a deployed BRS chute. I doubt that the Cessna was
useable again even though it was a symmetrical level attitude when it
hit with no drift. I'd hate to hit at a similar descent rate in a
glider. In Oz we've had a few people do hard landings in the last
couple of years. Some are considered lucky to be walking but the
gliders are repairable. Air bags may be essential.

Are your gliding club members smart enough to avoid inadvertent
deployment of a ballistic chute in the hangar? At one club I used to
belong to the new ASW20B got wheeled up twice in a month or so - in
the hangar as people said "what does this lever do?". In the chute
case you would hope nobody else was standing behind the wing looking
into the cockpit.

About 12 years ago we did a precision altimeter project for an RAAF
test project. The chief aero engineer of the research and development
unit was building an ultralight of his own design. I asked if he was
fitting a BRS chute. He said he was designing the aircraft basically
to high enough standards that like a FAR 23 power plane it was
reliable enough in its structure and control systems that flying
without a chute was a good risk. His opinion was that the whole ship
chutes at the time couldn't meet their claimed descent rates with the
chute sizes used. His first job had been with a parachute manufacturer
so I had to take some notice of his opinion.

Mike Borgelt


  #28  
Old February 11th 04, 09:35 PM
Eric Greenwell
external usenet poster
 
Posts: n/a
Default

Bill Daniels wrote:
OK, crank these numbers. Consider my Nimbus 2C (Experimental, so I

could
install a BRS) at 650 Kilos with water (which takes 5 minutes to dump). The
gear strut will give 30mm on impact and the tire will give 50mm more. The
cockpit shell is just fiberglass with no crush structure.

I pop a BRS at 300 meters AGL with the surface wind at 15 knots. What are
my chances? Give BRS weights, 'chute diameters and descent rates.


My understanding is the "whole glider" German rescue systems will lower
the glider nose down at about 40 degrees or so. If it is more level, it
is likely to oscillate wildly so much the descent and impact can't be
controlled. So, the landing gear is irrelevant, but the cockpit
structure is extremely important. The nose must absorb the "landing".

A Nimbus 2 might be a poor candidate for installing a system that won't
be tested, except when you really need it. Your safety might be better
served by selling the Nimbus and buying newer glider with a more crash
tolerant cockpit. At least in the US, crashing while landing (meaning
the last 100' of altitude) still claims more pilots than unsuccessful
bailouts.

--
-----
change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

  #29  
Old February 11th 04, 10:37 PM
Bill Daniels
external usenet poster
 
Posts: n/a
Default


"Eric Greenwell" wrote in message
...
Bill Daniels wrote:
OK, crank these numbers. Consider my Nimbus 2C (Experimental, so I

could
install a BRS) at 650 Kilos with water (which takes 5 minutes to dump).

The
gear strut will give 30mm on impact and the tire will give 50mm more.

The
cockpit shell is just fiberglass with no crush structure.

I pop a BRS at 300 meters AGL with the surface wind at 15 knots. What

are
my chances? Give BRS weights, 'chute diameters and descent rates.


My understanding is the "whole glider" German rescue systems will lower
the glider nose down at about 40 degrees or so. If it is more level, it
is likely to oscillate wildly so much the descent and impact can't be
controlled. So, the landing gear is irrelevant, but the cockpit
structure is extremely important. The nose must absorb the "landing".

A Nimbus 2 might be a poor candidate for installing a system that won't
be tested, except when you really need it. Your safety might be better
served by selling the Nimbus and buying newer glider with a more crash
tolerant cockpit. At least in the US, crashing while landing (meaning
the last 100' of altitude) still claims more pilots than unsuccessful
bailouts.


Eric Greenwell
Washington State
USA


OK, good info Eric - now we are getting down to it.

To summarize the thread so far:

The BRS requires a reinforced cockpit to absorb the non-trivial landing
impact forces. Most accidents involve premature termination of tow or
landing errors where a BRS 'chute wouldn't help anyway. Or perhaps,
mid-air collisions at an altitude where a personal 'chute is the equal for a
BRS for survivability.

A BRS is likely to require non-trivial pilot training and discipline in its
operation and maintenance. Injuries should be expected with the used of
either personal or BRS 'chutes.

On the other hand, taking the 'chute off the back of the pilot and putting
it on the glider adds significantly to ergonomics and comfort. The BRS can
be deployed at low altitudes where a pilot with a personal 'chute is
unlikely to make a successful egress. This altitude band favoring a BRS
probably expands where the pilot is old or infirm.

Maybe it's something to think about on a new glider but retrofitting an
older glider is problematical. A BRS is perhaps a useful option but not a
panacea. I remain skeptical but open to ideas.

Bill Daniels

  #30  
Old February 11th 04, 11:43 PM
Mark James Boyd
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Posts: n/a
Default

Dave Houlton wrote:
Jim Harper wrote:

Dave Houlton wrote in message ...

I believe that my parachute will lower me relatively nose-down, and as
such, my legs will protect me to some extent on landing. I feel safer
surrounded by the aluminum and plexiglass than if I were on my own
under canopy, given that I'll likley not be descending into a prepared
drop zone, more likely trees or worse...and I have around 500 sport
parachute and military jumps, so I speak from knowledge there.

Jim


It does help - thanks, Jim! I'm flying club gliders now, but I expect
I'll eventually be an owner - and based on this discussion I'll quite
likely opt for an experimental. It just makes sense to me that if
you're trying to leave yourself an out for when things go Really Bad,
you want that out to be usable in as many phases of flight as possible -
including low on tow or in the pattern. BRS seems like the only game in
town in those situations.


http://brsparachutes.com/PI_saves.mgi
 




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