Ballistic parachutes with pushers

On Sun, 16 May 2004 23:35:57 +0000, nauga wrote:

anonymous coward wrote...

The sort of designs I had in mind were the LongEZ or Junqua IBIS...

There are clearly slow-speed pushers with ballistic chutes, as I
think you knew based on some stuff I snipped. On a Long-Eze I'd be
more concerned about canopy/shroud strength and maximum deployment
speed rather than prop fouling. I'd bet adding a chute to a
fast cruiser where it wasn't designed in from the start would
either add a significant amount of weight in terms of additional structure

I'd been wondering the same. On hang-gliders the parachute is
attached to the pilot and not to the aircraft, so provided the pilot can
stand the opening shock it doesn't matter what happens to the wing - I
wonder if the answer is to attach the bridle to the pilot's seat rather
than the airframe.

AC


Dave 'strop size' Hyde

anonymous coward wrote...

I wonder if the answer is to attach the bridle to the pilot's
seat rather than the airframe.

http://www.martin-baker.co.uk/

Someone in Russia (Zvezda?) was marketing a lightweight
ejection seat for GA a while back. Dunno if they're
still around.

Dave 'back to the taxpayers' Hyde

Peter

I'd say you were the lucky one. The bird broke the flight before you
bought it and not the flight after.

Big John


On Mon, 17 May 2004 11:36:36 +1000, "Bushy"
wrote:

The hand thrown one that was used out here in the Australian outback about
four weeks ago (with no report) was thrown while the prop was still
rotating.

The steel cable was cut by the prop, but not before it damaged the wooden
prop beyond repair. The parachute did not remain with the aircraft after
that.

The aircraft was brought to the ground still under control and the
controlled crash did not injure anyone. (Apart from a serious pride injury!)

I know because I was talking to him that night about buying the advertised
aircraft and he had taken it up for a last spin........ and it started
running rough.......

He would have to be one of the luckiest blokes I have ever talked to.......

Peter

How many of the installations are professionally designed/tested? If people
are just bolting these devices on with no idea what will really happen
should the worst happen and they are forced to deploy, are they really
offering any safety advantage?

If the BRS is just going to pull free, damaging the airframe, maybe a pilot
would be better off with a parachute and letting the aircraft fare for
itself.

I'm sure these issues have come up before, was there any resolution?

On Tue, 18 May 2004 10:35:45 GMT, "Occom" wrote:

How many of the installations are professionally designed/tested? If people
are just bolting these devices on with no idea what will really happen
should the worst happen and they are forced to deploy, are they really
offering any safety advantage?

I think BRS has developed mounting instructions for many popular
ultralights, due to exactly this reason. I'm sure the company is happy to
help develop installations for new types.

Ron Wanttaja

On Tue, 18 May 2004 13:50:00 GMT, Ron Wanttaja
wrote:

:On Tue, 18 May 2004 10:35:45 GMT, "Occom" wrote:
:
:How many of the installations are professionally designed/tested? If people
:are just bolting these devices on with no idea what will really happen
:should the worst happen and they are forced to deploy, are they really
:offering any safety advantage?
:
:I think BRS has developed mounting instructions for many popular
:ultralights, due to exactly this reason. I'm sure the company is happy to
:help develop installations for new types.

I'm doing some work on a new, one-off ultralight with a friend, we're
putting a BRS on it. They are absolutely happy to help. It's
actually not all that complex. Attach the bridal to something that's
1) the strongest part of the airplane and 2) will dangle the airplane
in a reasonable attitude. Make sure that the pilot's seat and
seatbelt are attached to the airframe via a method 10 times as strong
as you think they need to be. Etc.

Of course, there's no reason you can't have both a BRS AND a personal
'chute. We intend to, especially for early flights.

Hi, I have an HP-16 in which I installed a BRS 1050hd. I can comment
on a few of the earlier comments:

1. ...substantial weight penalty. I didn't think so. Weighs 24 pounds
or so, total, including installation. Backpack parachute runs at least
12-14 pounds, so really, I don't see 10 pounds as a significant issue.

2...speed issues: The 1050 is rated to deploy at 172 mph. While my
HP-16 can go faster (assuming I am willing to sacrifice the wings),
given that BRS claims (quietly) at least a 150% safety margin, I ought
to be ok. Further the parachute is rated for 1050 pounds, and my
glider and I barely make 750. All the more margin.

3...when I use it, the glider is written off. You bet. If I need to
pull the handle, I will be in a situation wherein I would have chosen
to leave the airplane...which would write off the airplane for sure.

4. Why not just bail out? Well, basically, looking at the data, few
folks live who step out of their glider at less than around 1000 feet.
Mine would be particularly hard for ME to get out of, so that margin
might be cutting it close. Pull the handle, and I ought to have a
canopy at around 200 feet, assuming any non-downward velocity at all.
Seems safer to me.

The only real issue is the landing. The Cirri have their landing gear
to absorb the shock. Clearly a glider has less structure under it. I
have the system rigged to lower me fairly significantly nose down, and
I intend to lower the landing gear once under canopy. One hopes that
the rotation of the glider from the nose to the main gear will absorb
sufficient energy to protect my back. I suspect I would be better off,
however, with a canopy, than I would have been without in any
circumstance under which I would deploy the canopy.

I've included my email, feel free to correspond. If you write me, you
will have to go to the spamarrest website to get to me. It's easy, and
you'll get an email response telling you what to do. Great anti-spam
protection.

Jim

Bushy wrote:
The hand thrown one that was used out here in the Australian outback about
four weeks ago (with no report) was thrown while the prop was still
rotating.

The steel cable was cut by the prop, but not before it damaged the wooden
prop beyond repair. The parachute did not remain with the aircraft after
that.

The aircraft was brought to the ground still under control and the
controlled crash did not injure anyone. (Apart from a serious pride injury!)

I know because I was talking to him that night about buying the advertised
aircraft and he had taken it up for a last spin........ and it started
running rough.......

He would have to be one of the luckiest blokes I have ever talked to.......

Peter



No, you were quite a bit luckier. It wasn't your aircraft yet.

--
http://www.ernest.isa-geek.org/
"Ignorance is mankinds normal state,
alleviated by information and experience."
Veeduber

On Mon, 17 May 2004 10:36:04 +0100, anonymous coward
wrote:

On Sun, 16 May 2004 23:35:57 +0000, nauga wrote:

anonymous coward wrote...

The sort of designs I had in mind were the LongEZ or Junqua IBIS...

There are clearly slow-speed pushers with ballistic chutes, as I
think you knew based on some stuff I snipped. On a Long-Eze I'd be
more concerned about canopy/shroud strength and maximum deployment
speed rather than prop fouling. I'd bet adding a chute to a
fast cruiser where it wasn't designed in from the start would
either add a significant amount of weight in terms of additional structure

I'd been wondering the same. On hang-gliders the parachute is
attached to the pilot and not to the aircraft, so provided the pilot can
stand the opening shock it doesn't matter what happens to the wing - I
wonder if the answer is to attach the bridle to the pilot's seat rather
than the airframe.



The Air Force and Navy do that. They call it an ejection seat. :-)


--
dillon

When I was a kid, I thought the angel's name was Hark
and the horse's name was Bob.