A thought on BRS

On Tue, 27 Apr 2004 12:07:37 -0700, Eric Greenwell
wrote:

Bill Daniels wrote:
..../....

The 35 pounds
or so the BRS adds to the non-flying part of the glider bothers me too.

It would likely reduce the allowable cockpit load.

Surely, as the BRS would be installed on or just behind the CG, it
would be more like carrying a turbo in that the cockpit load would
remain as before but the permitted amount of water ballast would be
decreased.

--
martin@ : Martin Gregorie
gregorie : Harlow, UK
demon :
co : Zappa fan & glider pilot
uk :

Martin Gregorie wrote:
On Tue, 27 Apr 2004 12:07:37 -0700, Eric Greenwell
wrote:


Bill Daniels wrote:

..../....


The 35 pounds

or so the BRS adds to the non-flying part of the glider bothers me too.

It would likely reduce the allowable cockpit load.


Surely, as the BRS would be installed on or just behind the CG, it
would be more like carrying a turbo in that the cockpit load would
remain as before but the permitted amount of water ballast would be
decreased.

I simplified it a bit too much, perhaps. It would come out of the
"non-lifting parts" limit (basically the fuselage and everything in it).
Generally, the effect would be to reduce the cockpit allowed load, but
not always, depending on the exact weight of fuselage and installed
equipment. The amount of water ballast allowed would not likely change,
since it is carried by the wing (a lifting part), not the fuselage.

A glider designed to carry a motor will have a higher "non-lifting
parts" limit (perhaps from more structure, stronger lift pins, etc) than
a similar non-motorized one, in order to preserve the cockpit load.

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

Eric Greenwell
Washington State
USA

On Tue, 27 Apr 2004 16:17:51 -0400, Todd Pattist
wrote:


Their slow speeds and light
weight make the "rescue-the-aircraft parachutes" closer to a
sailplane "rescue the pilot only" parachute in terms of cost
and design difficulty.

Current ultralight aircraft like Impulse and Fascination have cruise
speeds of up to 270 kp/h and a weight of 472.5 kg... please compare
this to a typical glider...

The problem is the impact. Having one inch betweenmy butt and the
ground is a pretty short way to get rid of my 30 ft/sec sink rate.
This alone is the cause why I'd prefer a bailout help like Soteira in
a glider.



Bye
Andreas

Marc Ramsey wrote in message .com...
Tom Seim wrote:
by that benevolent dictator Jimmy Carter.

I miss the days when we had benevolent dictators,
rather than a not so benevolent one...


Ah yes, those days of gas shortages, 15% inflation and international
humiliation at the hands of a bunch of rabid teenagers. Such fond
memories...

Tom

(Tom Seim) wrote
I think the problem is tunnel vision safety analysis by "experts" that
vastly overrate their abilities. Part of the problem with the speed
limits is that drivers weren't obeying the limits to begin with.

I would suggest that this wasn't part of the problem but all of it.
You're right - speed limits were consistently ignored. Still are.

Draconian enforcement simply won't work, at least not (fortunately) in
the U.S., because law enforcement works only by voluntary compliance.
There simply are not enough cops and jails out there to impose a law
that the vast majority of the population won't accept.

I call bull****. What are you going to do - try to outrun the cop?
Not pay your ticket? Keep driving without a license when it gets
suspended? Join a militia? Get real. You will pay the first few
tickets, and then, when it's a matter of losing your license, you will
comply.

In any case, my point was not that we should have a 35 mph speed
limit. I'm in favor of no speed limit at all on the interstates, just
like the Germans have on the Autobahn. If that ever happens, I will
buy a sportscar again. My point was that a tradeoff between safety
and convenience/fun is reasonable, and anyone who says otherwise is
simply not being honest with himself.

Michael

On Tue, 27 Apr 2004 13:39:27 -0700, Eric Greenwell
wrote:

Martin Gregorie wrote:
On Tue, 27 Apr 2004 12:07:37 -0700, Eric Greenwell
wrote:


Bill Daniels wrote:

..../....


The 35 pounds

or so the BRS adds to the non-flying part of the glider bothers me too.

It would likely reduce the allowable cockpit load.


Surely, as the BRS would be installed on or just behind the CG, it
would be more like carrying a turbo in that the cockpit load would
remain as before but the permitted amount of water ballast would be
decreased.

I simplified it a bit too much, perhaps. It would come out of the
"non-lifting parts" limit (basically the fuselage and everything in it).
Generally, the effect would be to reduce the cockpit allowed load, but
not always, depending on the exact weight of fuselage and installed
equipment. The amount of water ballast allowed would not likely change,
since it is carried by the wing (a lifting part), not the fuselage.

A glider designed to carry a motor will have a higher "non-lifting
parts" limit (perhaps from more structure, stronger lift pins, etc) than
a similar non-motorized one, in order to preserve the cockpit load.

Thanks for the explanation.

--
martin@ : Martin Gregorie
gregorie : Harlow, UK
demon :
co : Zappa fan & glider pilot
uk :

"Bill Daniels" wrote in message
news:Jxvjc.42417$GR.5925024@attbi_s01...
I still have reservations about BRS, not because of the philosophy, but
I'm
not sure the engineers have all the bugs out of it. Any system that will
lower a disabled aircraft and its occupant(s) to the ground safely is a
very
good thing. The short history of the Cirrus BRS is very encouraging, at
least I haven't heard of any injuries to the passengers.

I know BRS has a long and exemplary record with ultralights but they are
slow and light and usually flown by the young and able. The idea of
hitting
the ground in a seated position at 20 FPS is disturbing to a 60 something
glider pilot. I know using a personal 'chute is just as problematic but I
would land with my legs under me. A broken leg is vastly better than a
broken back.

For now, personal 'chutes with egress aids like DG's NOAH look better to
me.
At least this idea could be retrofitted to an older glider. The 35 pounds
or so the BRS adds to the non-flying part of the glider bothers me too.

Bill Daniels
Bill,
I talked to the BRS people at the SSA convention a couple of years ago
regarding fitting one of their syatems to the Nimbus. They said no dice
because the energy absorption characteristics of the cockpit configuration,
descent rate, etc., etc., just wouldn't work.
Just as you said.
Streifeneder has been doing some certificatoin work in Germany on a retrofit
package for some ship but I do'nt remember the details. It looks like some
of the newer gliders may be taking the BRS sytem into account in in their
initial design now however.Too bad there's not an off the shelf retrofit
package.
Cheers!, Pete

Andreas Maurer wrote in
:

On Tue, 27 Apr 2004 16:17:51 -0400, Todd Pattist
wrote:

.... snip

The problem is the impact. Having one inch betweenmy butt and the
ground is a pretty short way to get rid of my 30 ft/sec sink rate.
This alone is the cause why I'd prefer a bailout help like Soteira in
a glider.



Bye
Andreas

How about the BRS plus an automotive type air bag under your butt that
could be deployed at the same time as the BRS?


--
Roger Kelly
to reply replace the IP address above with cgisenior.com

On 28 Apr 2004 13:36:04 GMT, Roger Kelly ] wrote:


How about the BRS plus an automotive type air bag under your butt that
could be deployed at the same time as the BRS?

An air bag under the butt is a good idea - but where?
Between butt and fuselage shell there is not enough space, and I doubt
that an airbag under the fuselage (opening through a hatch) will work
reliably.



Bye
Andreas

Actually such a system is available at DG Flugzeugbau. The NOAH system
works with a compressed air cilinder and a bag located under the cushion in
the glider. It lifts to over the canopy rim and lets you just roll out of
the cockpit

See:

http://www.dg-flugzeugbau.de/noah-e.html

Roelant van der Bos


Andreas Maurer wrote:

On 28 Apr 2004 13:36:04 GMT, Roger Kelly ] wrote:

How about the BRS plus an automotive type air bag under your butt that
could be deployed at the same time as the BRS?

An air bag under the butt is a good idea - but where?
Between butt and fuselage shell there is not enough space, and I doubt
that an airbag under the fuselage (opening through a hatch) will work
reliably.

Bye
Andreas