taxi in reverse?

[[email protected]]

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

[Steven P. McNicoll]

> 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.

[James M. Knox]

"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
-----------------------------------------------

[BTIZ]

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?

[One's Too Many]

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.

[James M. Knox]

(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
-----------------------------------------------

[Michelle P]

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?
>
>

[Malcolm Teas]

"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

[James M. Knox]

(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
-----------------------------------------------

[G.R. Patterson III]

"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.

[Corky Scott]

>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
>-----------------------------------------------

Two things: 1. Some hangars have slightly slanted floors such that
when the chocks are removed, the airplane wants to roll out. They
have to be winched in of course but lots of hangars have winches to
reel the airplane in without a slanted floor.

2. If it's cold and rainy, you're flying? ;-)

Corky Scott

[Jay]

Thats a cool idea even if it goes counter to the homebuilt creed "Keep
it simple stupid." Maybe you compromise on the brake function,
keeping your brakes on the mains, and put the motor on the castering
nose gear. Steer like usual with differential braking.

That might be a lot of juice stopping a 1,000 lb airplane from 60mph
to 0 in 10 seconds. Loads are easy though, you don't have to dump
that power into your battery. Think of it the other way around, how
much power would you need to accelerate 1,000lb to 60MPH in 10
seconds?

Modern jet fighters dump waste heat from the hydraulic system into
their wing tanks. Worst case scenario, heavy manuvering on low tanks.



"James M. Knox" > wrote in message >...
> (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
> -----------------------------------------------

[Capt.Doug]

>"James M. Knox" wrote in message 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.

The electric motor on my hybrid car is 6 cm thick and the diameter is larger
than some homebuilts' tires. It's rated for 10 hp and it's hooked into a 144
volt battery which weighs more than I do. The motor goes into regenerative
mode for braking. It recharges the battery in quick order, but it doesn't
stop the 2800 pound car very well. Based on this, I'm inclined to think that
you will still need traditional brakes.

D.

[arcwi]

What one should use is to replace the front weel hub wtih a hub-motor
http://www.goldenmotor.com/ .
I am sure that this would not add that much weight and if the hub-motor is
selected corectly, the original tyre used, one could not distinguish it form
original.
Now, I wander if this could be installed on a certified aicraft with some
field approval as a minor modification...

"James M. Knox" > wrote in message
...
> (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
> -----------------------------------------------

[Ernest Christley]

arcwi wrote:
> What one should use is to replace the front weel hub wtih a hub-motor
> http://www.goldenmotor.com/ .
> I am sure that this would not add that much weight and if the hub-motor is
> selected corectly, the original tyre used, one could not distinguish it form
> original.
> Now, I wander if this could be installed on a certified aicraft with some
> field approval as a minor modification...
>

The largest one is 500W, a little less than 1Hp. (Is that right?) Just
barely enough power to push a light aircraft out of the hanger? Now how
much does it weigh (along with the 500W voltage converter to go from 12
to 36V)?

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

[David Lesher]

I once, on a flight from Bogota to MIA, sat next to an ex-FBI agent,
ex-Customs pilot, then MD for PHS.

He talked about making short field landings in a King Air by going
into reverse pitch while still 50 ft above the dirt.... ARGH!


--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

[David Lesher]

You can put a small winch at the back of the hangar to pull
you in, but yes, you must get out to attach it.
--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

[Bushy]

> He talked about making short field landings in a King Air by going
> into reverse pitch while still 50 ft above the dirt.... ARGH!
>

Known as Beta Mode in a Porter, and was used to drop from the sky at a great
rate of knots when you wanted to get down in a hurry. It has been used for
parachuting and allows the aircraft to get down faster than the jumpers.....

Also good for taxi operations.

I am considering a Storch, www.storch.com.au and have just had a great chat
with the designer about this and a few other things. Looks like I'm about to
take a trip down to see him......

Peter

[G.R. Patterson III]

David Lesher wrote:
>
> He talked about making short field landings in a King Air by going
> into reverse pitch while still 50 ft above the dirt.... ARGH!

The technique was commonly used by CIA pilots for short field insertions in SEA.

George Patterson
A diplomat is a person who can tell you to go to hell in such a way that
you look forward to the trip.

[Blueskies]

That's funny!

--
Dan D.



..
"Boogerz" > wrote in message ...
> Shortly after I first got my ticket, I took my wife and kids to see family
> in a 172. At the other airport, we were told to back up to a fence. So, I
> shut down and pushed the plane into place.
>
> My wife was furious about something as we walked thru the terminal to meet
> family...finally she blurts out "I've never been so embarassed in my life!
> I'm not going anywhere with you again until you learn to use the reverse."
>
>
> "David Lesher" > wrote in message
> ...
> >
> > You can put a small winch at the back of the hangar to pull
> > you in, but yes, you must get out to attach it.
> > --
> > A host is a host from coast to
> > & no one will talk to a host that's close........[v].(301) 56-LINUX
> > Unless the host (that isn't close).........................pob 1433
> > is busy, hung or dead....................................20915-1433
>
>

[Boogerz]

Shortly after I first got my ticket, I took my wife and kids to see family
in a 172. At the other airport, we were told to back up to a fence. So, I
shut down and pushed the plane into place.

My wife was furious about something as we walked thru the terminal to meet
family...finally she blurts out "I've never been so embarassed in my life!
I'm not going anywhere with you again until you learn to use the reverse."


"David Lesher" > wrote in message
...
>
> You can put a small winch at the back of the hangar to pull
> you in, but yes, you must get out to attach it.
> --
> A host is a host from coast to
> & no one will talk to a host that's close........[v].(301) 56-LINUX
> Unless the host (that isn't close).........................pob 1433
> is busy, hung or dead....................................20915-1433