Fly-By-Wire Flight Controls

Alternatively, I've always wondered if one could not keep a special
reserve tank for the APU. When the engines quit, the APU
automatically starts to power the controls. Would such a system be
safe and would it be certifiable? Would it weigh less than the
existing system?

In a lot of airplanes the APUs (resp. their intakes and exhausts) are
mounted in a way that they can't be used inflight. Besides that, if
there still is fuel in the tanks it's better served for keeping the
engine alive than just the APU...

I know that most Boeing and Airbus planes can run the APU in the air.

I'm just asking if 30 minutes of fuel for the APU might not weigh less
than
the ram air turbine. The APU would clearly produce more power than the
ram air turbine.

If the choice was between flight controls powered for 30 minutes or the
main
engines powered for another one minite, I would take the former.

I must assume that there are some very smart aircraft designers who
have already
considered and rejected my idea. But WHY was this? Is it a
fundementally
bad idea, is it a good idea that's against the rules of certification,
or what?

-Charles Talleyrand

Charles Talleyrand wrote:
Alternatively, I've always wondered if one could not keep a special
reserve tank for the APU. When the engines quit, the APU
automatically starts to power the controls. Would such a system be
safe and would it be certifiable? Would it weigh less than the
existing system?


In a lot of airplanes the APUs (resp. their intakes and exhausts) are
mounted in a way that they can't be used inflight. Besides that, if
there still is fuel in the tanks it's better served for keeping the
engine alive than just the APU...


I know that most Boeing and Airbus planes can run the APU in the air.

I'm just asking if 30 minutes of fuel for the APU might not weigh less
than
the ram air turbine. The APU would clearly produce more power than the
ram air turbine.

If the choice was between flight controls powered for 30 minutes or the
main
engines powered for another one minite, I would take the former.

I must assume that there are some very smart aircraft designers who
have already
considered and rejected my idea. But WHY was this? Is it a
fundementally
bad idea, is it a good idea that's against the rules of certification,
or what?

-Charles Talleyrand


For one thing you'd be hard pressed to get 30 minutes of glide time
from any airliner.

Dan, U.S. Air Force, retired

"Dan, U.S. Air Force, retired" wrote in message
news:yDepf.66209$sg5.26836@dukeread12...
Charles Talleyrand wrote:



For one thing you'd be hard pressed to get 30 minutes of glide time from
any airliner.

Dan, U.S. Air Force, retired

The Air Transat Airbus that ran out of fuel glided for 20 minutes
to get to the Azores

Keith

"Keith W" wrote in message
...

"Dan, U.S. Air Force, retired" wrote in message
news:yDepf.66209$sg5.26836@dukeread12...
Charles Talleyrand wrote:



For one thing you'd be hard pressed to get 30 minutes of glide time
from any airliner.

Dan, U.S. Air Force, retired

The Air Transat Airbus that ran out of fuel glided for 20 minutes
to get to the Azores

Keith


And there is the 1983 (?86) story of the "Gimli Glider." An Air Canada
B-767 that ran out of fuel and landed on an X-ed out runway in Canada that
was, at the time, in use by sports car racers. See:

http://www.silhouet.com/motorsport/tracks/gimli.html

for a great photo. They talk about the RATS but I couldn't find any remarks
about elapsed glide time in this story.

For giggles, read the post script story about the mechanics who went to
rescue the airplane.

"Casey Wilson" N2310D @ gmail.com wrote in
news:qokpf.21228$eI5.17594@trnddc05:


"Keith W" wrote in message
...

"Dan, U.S. Air Force, retired" wrote in message
news:yDepf.66209$sg5.26836@dukeread12...
Charles Talleyrand wrote:



For one thing you'd be hard pressed to get 30 minutes of glide time
from any airliner.

Dan, U.S. Air Force, retired

The Air Transat Airbus that ran out of fuel glided for 20 minutes
to get to the Azores

Keith


And there is the 1983 (?86) story of the "Gimli Glider." An Air
Canada
B-767 that ran out of fuel and landed on an X-ed out runway in Canada
that was, at the time, in use by sports car racers. See:

http://www.silhouet.com/motorsport/tracks/gimli.html

for a great photo. They talk about the RATS but I couldn't find any
remarks about elapsed glide time in this story.

For giggles, read the post script story about the mechanics who went to
rescue the airplane.

HAHAHAHAA...too funny....I'd quote it but don't want to be
a spoiler.

I also liked the part about what was heard on the voice recorder
after the EICAS went "bong"..."Oh F___".

Damned good flying.

I would have officially christend that plane the "Gimli Glider"
and painted it's nose with it. I wonder if it's still in service
today. That plane's got good karma.

Brian
--
http://www.skywise711.com - Lasers, Seismology, Astronomy, Skepticism
Seismic FAQ: http://www.skywise711.com/SeismicFAQ/SeismicFAQ.html
Quake "predictions": http://www.skywise711.com/quakes/EQDB/index.html
Sed quis custodiet ipsos Custodes?
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Skywise wrote:
Damned good flying.

I would have officially christend that plane the "Gimli Glider"
and painted it's nose with it. I wonder if it's still in service
today. That plane's got good karma.

http://www.airliners.net/search/phot...eywords=C-GAUN

Still in service

"James Hart" wrote in
:

Skywise wrote:
Damned good flying.

I would have officially christend that plane the "Gimli Glider"
and painted it's nose with it. I wonder if it's still in service
today. That plane's got good karma.

http://www.airliners.net/search/phot...es=500&keyword
s=C-GAUN

Still in service

Thank you!

Brian
--
http://www.skywise711.com - Lasers, Seismology, Astronomy, Skepticism
Seismic FAQ: http://www.skywise711.com/SeismicFAQ/SeismicFAQ.html
Quake "predictions": http://www.skywise711.com/quakes/EQDB/index.html
Sed quis custodiet ipsos Custodes?
Like censorship and not getting support help? Switch to Supernews!
They won't even answer questions through your ISP!

"Casey Wilson" N2310D @ gmail.com wrote in message news:qokpf.21228$eI5.17594@trnddc05...

"Keith W" wrote in message ...

"Dan, U.S. Air Force, retired" wrote in message news:yDepf.66209$sg5.26836@dukeread12...
Charles Talleyrand wrote:



For one thing you'd be hard pressed to get 30 minutes of glide time from any airliner.

Dan, U.S. Air Force, retired

The Air Transat Airbus that ran out of fuel glided for 20 minutes
to get to the Azores

Keith


And there is the 1983 (?86) story of the "Gimli Glider." An Air Canada B-767 that ran out of fuel and landed on an
X-ed out runway in Canada that was, at the time, in use by sports car racers. See:

http://www.silhouet.com/motorsport/tracks/gimli.html

for a great photo. They talk about the RATS but I couldn't find any remarks about elapsed glide time in this story.

For giggles, read the post script story about the mechanics who went to rescue the airplane.


Here is a link to the RAT:
http://www.hamiltonsundstrandcorp.co..._PRD38,00.html

We make the hydraulic pump portion:
http://www.parker.com//ead/cm2.asp?cmid=2841

A higher flying Airbus or B747-400 at 44,000ft might have glided nearly
30 minutes. This suggests that a fighter plane with its lower glide
ratio probably only needs half the amount of time (10 minutes) which
suggests that a thermal battery is possibly more efficient or at least
adaquet whereas an airliner may need twice as much.

What seems extraordinary is that both airbus and boeing designers have
provided insufficient RAT power to opperate all systems: spoilers,
flaps, undercarriage seem to be neglected. This makes an emegency
landing much harder. In both the airbus A330-200 azores and boeing 767
gimli fuel out landing case the lack of spoilers added a great deal of
risk as pilots manouvered agressively to loose altitude and speed for
runway lineup.

"Eunometic" wrote in message
ups.com...
A higher flying Airbus or B747-400 at 44,000ft might have glided nearly
30 minutes. This suggests that a fighter plane with its lower glide
ratio probably only needs half the amount of time (10 minutes) which
suggests that a thermal battery is possibly more efficient or at least
adaquet whereas an airliner may need twice as much.

What seems extraordinary is that both airbus and boeing designers have
provided insufficient RAT power to opperate all systems: spoilers,
flaps, undercarriage seem to be neglected. This makes an emegency
landing much harder. In both the airbus A330-200 azores and boeing 767
gimli fuel out landing case the lack of spoilers added a great deal of
risk as pilots manouvered agressively to loose altitude and speed for
runway lineup.


If you add more power to the RAT you increase drag and reduce the
glide distance, the record suggests they made the right trade offs.

Keith