Aircraft Deceleration Devices

[SteveM8597]

A non flying software engineer friend of mine insistes it is poossible to put
devices on a plane to make it safer by impacting the ground at a low velocity
after loss of control or catastrophic failure, or to be able to manuever to
miss an obstacle when impact is imminent. These devices would include
retrorockets, large recovery chutes, airbrake type control surfaces, warpable
wings, and software on airplanes. Ballistic recovery systems have had
successes on light planes and ultralights Otherwise, I have told him that the
above have been proven to be impractical and even dangerous. He insists that
technology is there that would allow either an out of control or powerless
heavy to eiher recover or hit the ground softly enough that it would be
survivable. I've got 34 years in the business and a degree in aero engineering
but he seems to think I am just being negative.

Any comments or knowledge of potential technolgy I can feed his pipe dreasm
with?

Steve

[Boomer]

I seem to remember McAir(maybee someone else) putting forth an idea for a
large parasail for airliners back in the late 70s?

--



Curiosity killed the cat, and I'm gonna find out why!
"SteveM8597" > wrote in message
...
> A non flying software engineer friend of mine insistes it is poossible to
put
> devices on a plane to make it safer by impacting the ground at a low
velocity
> after loss of control or catastrophic failure, or to be able to manuever
to
> miss an obstacle when impact is imminent. These devices would include
> retrorockets, large recovery chutes, airbrake type control surfaces,
warpable
> wings, and software on airplanes. Ballistic recovery systems have had
> successes on light planes and ultralights Otherwise, I have told him that
the
> above have been proven to be impractical and even dangerous. He insists
that
> technology is there that would allow either an out of control or powerless
> heavy to eiher recover or hit the ground softly enough that it would be
> survivable. I've got 34 years in the business and a degree in aero
engineering
> but he seems to think I am just being negative.
>
> Any comments or knowledge of potential technolgy I can feed his pipe
dreasm
> with?
>
> Steve

[tscottme]

SteveM8597 > wrote in message
...
> A non flying software engineer friend of mine insistes it is poossible
to put
> devices on a plane to make it safer by impacting the ground at a low
velocity
> after loss of control or catastrophic failure, or to be able to
manuever to
> miss an obstacle when impact is imminent. These devices would include
> retrorockets, large recovery chutes, airbrake type control surfaces,
warpable
> wings, and software on airplanes. Ballistic recovery systems have had
> successes on light planes and ultralights Otherwise, I have told him
that the
> above have been proven to be impractical and even dangerous. He
insists that
> technology is there that would allow either an out of control or
powerless
> heavy to eiher recover or hit the ground softly enough that it would
be
> survivable. I've got 34 years in the business and a degree in aero
engineering
> but he seems to think I am just being negative.
>
> Any comments or knowledge of potential technolgy I can feed his pipe
dreasm
> with?
>
> Steve

Didn't he see the movie "Air Force One"? We just need ejection pods,
and lots of them.

I'd suggest something from the sci-fi types: take 3 times more energy
than is in the universe, confine it to an area 1/3 the size of a
singularity, and then accelerate that to 8 times the speed of light and
all problems are solved.

--


Scott
--------
"I'm an internationalist. I'd like to see our troops dispersed through
the world only at the directive of the United Nations," and that he
wants "to almost eliminate CIA activity."
John F. Kerry, 1970 Harvard Crimson

[Urban Fredriksson]

In article >,
SteveM8597 > wrote:

>Any comments or knowledge of potential technolgy I can feed his pipe dreasm
>with?

Since it would come at a performance cost it would mean
either you get less range, can deliver less payload to the
target or, perhaps most importantly, decrease overall
survivability. Besides, as opposed on civilian aircraft,
military pilots very often have good systems for leaving
their aircraft relatively safely.
--
Urban Fredriksson http://www.canit.se/%7Egriffon/
There is always a yet unknown alternative.

[The Enlightenment]

"SteveM8597" > wrote in message
...
> A non flying software engineer friend of mine insistes it is
poossible to put
> devices on a plane to make it safer by impacting the ground at a low
velocity
> after loss of control or catastrophic failure, or to be able to
manuever to
> miss an obstacle when impact is imminent. These devices would
include
> retrorockets, large recovery chutes, airbrake type control surfaces,
warpable
> wings, and software on airplanes.

The world is full of technical experts whose education has assured
them that something was impossible only to be latter proven as wrong.

My qualifications are in controls engineering. In favour of your
friend let me say that now we have accelerometers, rate gyroscopes,
tiltmeters and inclinometers as well as single chip radars. The
devices are called MEMS (micro mechanical systems) these mean that
we have the sensors and intelligence to do at least part of what your
friend says on a single printed circuit board. We will know the
attitude of the aircraft and the rate it might be spining, how far of
the ground it is and how fast it is approaching even from the radar
what type of terrain and objects are in it.

You will note that BRS ballistic recovery systems
http://sbir.gsfc.nasa.gov/SBIR/successes/ss/1-005text.html has
developed a parachute for the cirus SR20 light aicraft.

So at least for light aircraft you friend is right!

As an aeronautical engineer you might be able to research whether
there are any inherent limitations to the size of a parachute cannopy.
From what I can see about 16 sqare meters of canopy are required for
each 100kg. If we wanted to recover an empty 80 ton C-17 or M1
Abrams Tank we would need around 4000 sqaure meters which seems to me
to be about a 70 meter diameter cannopy (230 feet)

I do not know if there are any physical law limitations to parachute
scaling. Could we recover a large aircraft like a C130 Hercules, use
this as a form of STOVL or deliver a medium or even heavy tank?

Certainly the Apolo command module chute system seems to indicate that
at least 25 tons or so is feasilble and the way the Russians use a
reto rocket activated a meter above the ground indicates that a
landing can be cushioned.

Parachutes can ofcourse also be steered.

A vietnam UH1 Iroqois pilot in the RAAF told me they were not to
concerned with loss of the tail rotor in forward flight. It was
merely a matter of autorotating with the natural forces of the forward
flight on the tail boom straightening the aircraft and making a
semi-controlled landing possible.

I've often wondered whether is would be possible to recover an
aircraft such as a Blackhawke whose main rotor had been destroyed or
even lost a complete rotor blade.

A basic system would consist of a heavily armoured contol system which
which would contain a single chip based system of gyroscopes and
accelerometers.

When activated the system would fire series of retro rockets to right
the vehicle in both a crashworthy attitude or an attitude in which a
stabalising drogue chute can be deployed by rocket. Befor impacting
the ground a reto rocket can be fired. The drogue chute can be built
into the rotor hub for instance.

More sophisticated systems might be able to use explosieve bolts to
release damaged rotor blades or even eject the whole rotor,engine,
gearbox package (thus minimising the damage casued by rotor blades
flying of)

Even without a drogue such a system by putting the stricken chopper
into a crashworthy attitude could save a crew whose chopper was
damaged close to the ground.

The retro rockets would have to be designed. Gas pressure delivered
hypergolic propellants would work but this is probably likely to add
danger. A 25kg turobjet could deliver 250kg thrust and a pair of
these might be enough.

The controls might consist of several independent systems all
independantly capable of control and networked via multiple pathes.
Even if the pathes were destroyed the system could be capable of doing
its job.

As far as making an airliner recoverable you would have to decide if
the several tons of system to do this would not be better spent in
other areas.

The particular car I drive has the best breakdown record of any car
mainly because of its oversized battery.

The military might find such technology more usefull.

> Ballistic recovery systems have had
> successes on light planes and ultralights Otherwise, I have told him
that the
> above have been proven to be impractical and even dangerous.

What is impracticable about them in larger vehicles. Be precise.

[Cub Driver]

>Any comments or knowledge of potential technolgy I can feed his pipe dreasm
>with?

Indeed! You can buy a parachute for a lightplane. They have saved more
than one plane/pilot, one as recently as 2003.

(Of course there's always the question in such cases as to whether,
without the parachute, the pilot would have been able to make an
emergency landing. In this case the plane didn't lose a wing or its
tail feathers, as I recall.)

all the best -- Dan Ford
email: (put Cubdriver in subject line)

The Warbird's Forum www.warbirdforum.com
The Piper Cub Forum www.pipercubforum.com
Viva Bush! blog www.vivabush.org

[SteveM8597]

>As far as making an airliner recoverable you would have to decide if
>the several tons of system to do this would not be better spent in
>other areas.
>
>The particular car I drive has the best breakdown record of any car
>mainly because of its oversized battery.
>
>The military might find such technology more usefull.
>
>> Ballistic recovery systems have had
>> successes on light planes and ultralights Otherwise, I have told him
>that the
>> above have been proven to be impractical and even dangerous.
>
>What is impracticable about them in larger vehicles. Be precise.

You pretty much hit the nail on the weight and safety; and of course cost,
unless madated. Commerical operators will spring for a 3000# entertainment
sustem for an airliner but not a 200# system that guards against electrical
shorts such as the one that brought TWA 800 down accoring to a recent
documentary on US TV. Also the overall cost has to be hustified in terms of
potential lives saved. The airlines use $2.6 million as a figure to calculate
cost vs benefit according to tht same documentary..

[Dave Holford]

Cub Driver wrote:
>
> >Any comments or knowledge of potential technolgy I can feed his pipe dreasm
> >with?
>
> Indeed! You can buy a parachute for a lightplane. They have saved more
> than one plane/pilot, one as recently as 2003.
>
> (Of course there's always the question in such cases as to whether,
> without the parachute, the pilot would have been able to make an
> emergency landing. In this case the plane didn't lose a wing or its
> tail feathers, as I recall.)
>
> all the best -- Dan Ford
> email: (put Cubdriver in subject line)
>
> The Warbird's Forum www.warbirdforum.com
> The Piper Cub Forum www.pipercubforum.com
> Viva Bush! blog www.vivabush.org


There was one on Thursday night over the Monashee mountains in British
Columbia. The parachute appears to have resulted in a survivable impact
and all four on board survived basically uninjured.

Dave

[WaltBJ]

Cub Driver > wrote in message >...
> >Any comments or knowledge of potential technolgy I can feed his pipe dreasm
> >with?
>
>First look off the top of my head - jettison the wings and tail,
getting rid of the weight of the engines and the gear. A drogue chute
can stabilize the fuselage until time for main chute(s) deployment.
Pop the chute(s) by radio altimeter and when close to the ground
deploy giant air bags to cushion impact. You figure out how to
stabilize the fuselage after impact and keep it afloat if it lands on
water. Also figure out how to prevent premature/accidental activation.
Tell him sure it can be done - he can write a program to determine the
economical cost of the kluge, and what the result in airline ticket
prices will be. Don't forget the inspection costs of all the new
stuff. I have no idea how much it costs to repack one of the BRS
chutes or even what the inspection requirements are. Costs will
probably parallel writing totally bug-free Windows.
Walt BJ

[The Enlightenment]

(SteveM8597) wrote in message >...
> >As far as making an airliner recoverable you would have to decide if
> >the several tons of system to do this would not be better spent in
> >other areas.
> >
> >The particular car I drive has the best breakdown record of any car
> >mainly because of its oversized battery.
> >
> >The military might find such technology more usefull.
> >
> >> Ballistic recovery systems have had
> >> successes on light planes and ultralights Otherwise, I have told him
> that the
> >> above have been proven to be impractical and even dangerous.
> >
> >What is impracticable about them in larger vehicles. Be precise.
>
> You pretty much hit the nail on the weight and safety; and of course cost,
> unless madated. Commerical operators will spring for a 3000# entertainment
> sustem for an airliner but not a 200# system that guards against electrical
> shorts such as the one that brought TWA 800 down accoring to a recent
> documentary on US TV. Also the overall cost has to be hustified in terms of
> potential lives saved. The airlines use $2.6 million as a figure to calculate
> cost vs benefit according to tht same documentary..


The BRS recovery chute is probably lighter than giving each passenger
an ejection seat. It is infinetly more practical than expecting
people in what is essentially a pleasure craft to strap into ejection
seats etc.

As aircraft weight (and speed?) goes up egress by ejection seat
becomes more attractive because 'whole of aircraft'

Where I would see some value to 'whole of aircraft' recovery is in the
area of smaller troop transports and combat troop helicopters where
the aircraft opperates so close to the ground.

Perhaps aircraft as large as a Bombadier Dash 8 or Buffalo/Carribu
would handle a recovery chute. Apart from the safety aspects it might
in combination with a RATO system form the basis of a special missions
aircraft.

[Keith Willshaw]

"SteveM8597" > wrote in message
...
> A non flying software engineer friend of mine insistes it is poossible to
put
> devices on a plane to make it safer by impacting the ground at a low
velocity
> after loss of control or catastrophic failure, or to be able to manuever
to
> miss an obstacle when impact is imminent. These devices would include
> retrorockets, large recovery chutes, airbrake type control surfaces,
warpable
> wings, and software on airplanes. Ballistic recovery systems have had
> successes on light planes and ultralights Otherwise, I have told him that
the
> above have been proven to be impractical and even dangerous. He insists
that
> technology is there that would allow either an out of control or powerless
> heavy to eiher recover or hit the ground softly enough that it would be
> survivable. I've got 34 years in the business and a degree in aero
engineering
> but he seems to think I am just being negative.
>
> Any comments or knowledge of potential technolgy I can feed his pipe
dreasm
> with?
>


It may well be technically possible but the challenge is to
develop a system at affordable cost that doesnt impose
unreasonable performance constraints and that performs
reliably enough to decrease risks.

For example consider the case of a ballistic recovery system
designed to allow an aircraft to 'parachute' to safety. The number
of situations in which such a system would have helped seems
small given that must airliner accidents happen at landing
or takeoff or involve controlled flight into terrain rather
than a technical failure. The result of such a system deploying
accidentally mid Atlantic would be unfortunate so it must be
rather more reliable than the aircraft itself, a non trivial task
when one considers how rarely aircraft have crashed due
to techical faults.

Keith