taxi in reverse?

Has a fixed-wing plane ever been made that could back up under its own
power?

wrote in message
...

Has a fixed-wing plane ever been made that could back up under its own
power?


Many. All it takes is reverse pitch props or thrust attenuators.

"Steven P. McNicoll" wrote in
ink.net:

Has a fixed-wing plane ever been made that could back up under its own
power?

Many. All it takes is reverse pitch props or thrust attenuators.

Not even that. Heck, many an old-timer B-17 pilot could back up into his
parking place, with a little practice.


-----------------------------------------------
James M. Knox
TriSoft ph 512-385-0316
1109-A Shady Lane fax 512-366-4331
Austin, Tx 78721
-----------------------------------------------

Most fixed wing aircraft with turbine engines and reversible pitch
propellers are the norm for backing.. ever watch a King Air do a "K-turn" on
a taxi way that was too narrow to turn around on?

some may be "limited" in it's reverse mode for blowing dirt and debris from
the ground up into the engine intakes..

BT

wrote in message
...
Has a fixed-wing plane ever been made that could back up under its own
power?

wrote in message . ..
Has a fixed-wing plane ever been made that could back up under its own
power?

I once watched a Bonanza back into it's hangar. The plane sure isn't
built for backing up, but the concrete ramp from the taxiway to the
hangar door was on a downhill incline, and the old rancher who owns
the plane has learned to pull off the taxiway and turn around in front
of his hangar with the nose pointing forwards uphill, then uses a
remote control opener to open his hangar door, and rolls backwards
from gravity into his hangar and closes the door once inside all
without leaving the aircraft. I wonder what his insurance agent thinks
about this practice?... sure could be a good way to prang a wingtip on
the way inside, or perhaps crunch the ruddervators into the back wall
of the hangar if he ever misjudges his clearance.

(One's Too Many) wrote in
om:

I once watched a Bonanza back into it's hangar. The plane sure isn't
built for backing up, but the concrete ramp from the taxiway to the
hangar door was on a downhill incline,
remote control opener to open his hangar door, and rolls backwards
from gravity into his hangar and closes the door once inside all
without leaving the aircraft.

I always figured if I was building a homebuilt I would investigate some
relatively small motor/brake assemblies that are used on smaller electric
automobiles. May be WAY too heavy, but they make great brakes that don't
fade with heat ... *AND* you could just taxi out of the hangar (before
starting the engine).

-----------------------------------------------
James M. Knox
TriSoft ph 512-385-0316
1109-A Shady Lane fax 512-366-4331
Austin, Tx 78721
-----------------------------------------------

Many jets do a power back from gates at the major airports.
All of our Aircraft can back up if necessary.
I have "witnessed" our turboprops backed into their parking spaces at
our hangar. You do not use the brakes though when backing up. They grab
and up end up doing a tail stand. (not good)
These would be a Jetstream 4100 and our Canadair Regional Jets
Michelle

wrote:

Has a fixed-wing plane ever been made that could back up under its own
power?

"James M. Knox" wrote in message ...
I always figured if I was building a homebuilt I would investigate some
relatively small motor/brake assemblies that are used on smaller electric
automobiles. May be WAY too heavy, but they make great brakes that don't
fade with heat ... *AND* you could just taxi out of the hangar (before
starting the engine).

My first thought when reading this was, "sounds cool!". And I started
to think it through. The motor part is clear enough, you can taxi
with electric power and not with the engine power. That'd lead to a
real difference in taxiing of course. You can't use engine power to
bring the rudder around for example. But this is workable, it just
becomes part of this plane's checkout procedure.

In the brake mode though, there's a problem. Either the motor/brakes
now work as generators or as motors in reverse. If the first, where
you put the power that's generated? Your battery's been charging off
the engine, it's already full and not drawing current. Your braking
power is directly related to the power you can cause to be used up on
something else. I imagine you can make your landing light really
bright or something... grin

The generator mode makes more sense in a hybrid aircraft, like hybrid
cars with regenerative brakes. But the problem with this is that
lightweight high-capacity batteries are not yet available.

If the brakes are operating as motors in reverse that solves the
generator problem. But it creates a new one. What happens if your
battery or electrical system dies? No brakes. But if you've got the
power, you should be able to get more braking from reversed electric
motors than current braking systems. Current braking systems convert
momentum to heat. Their braking capacity is directly releated to
their limit in heat capacity. Electrical reversed motors would have a
heat limitation, but the initial limiting factor would be the power
input.

Fun idea!

-Malcolm Teas

(Malcolm Teas) wrote in
om:

"James M. Knox" wrote in message
I always figured if I was building a homebuilt I would investigate
some relatively small motor/brake assemblies that are used on smaller
electric automobiles.

My first thought when reading this was, "sounds cool!". And I started
to think it through.

All true. Of course, I was thinking primarily in terms of taxiing only a
short distance - into or out of a hangar, for example. I haven't done the
brake calculations, but I *think* (back of the hand calculations) that the
amount of power generated stopping the plane on the runway and taxiing in
is small enough that even a "fully charged" battery can easily absorb it.

Mostly just amusing and idle speculation... But I've seen some cold rainy
days when it would sure be nice to preflight in the hangar, climb in, and
just drive out. G

-----------------------------------------------
James M. Knox
TriSoft ph 512-385-0316
1109-A Shady Lane fax 512-366-4331
Austin, Tx 78721
-----------------------------------------------

"James M. Knox" wrote:

Mostly just amusing and idle speculation... But I've seen some cold rainy
days when it would sure be nice to preflight in the hangar, climb in, and
just drive out. G

So, build a steel frame which supports the wheels of the plane. Put that frame on
wheels. Use a garage door opener to move it in and out of the hangar.

George Patterson
Love, n.: A form of temporary insanity afflicting the young. It is curable
either by marriage or by removal of the afflicted from the circumstances
under which he incurred the condition. It is sometimes fatal, but more
often to the physician than to the patient.