Flying in Reverse?

[jerrytug]

Would it be possible to design an aircraft to fly forwards OR BACKWARDS equally well? It`s a question from my mate`s little boy who is hot on aerodynamics and we will try and work it out. I am thinking fixed-wing,glider to start off just to keep it simple. Perhaps a push-me pull-you canard with a h-stab at both ends. And could a piloted version change direction (ahead to astern) IN FLIGHT?
Gratefull for any thoughts,children ask such awkward Q`s,Jerry:confused:

[Mad (Flt) Scientist]

To fly "equally well" you'd need the plane to basically be symmetric front-to-back. Which would involve some pretty horrible wing geometry (identical trailing and leading edge shapes, no washout, etc.) You'd also probably have to forgoe conventional controls, as it's hard to see how you'd get decent flaps, ailerons, spoilers etc to work, unless you simply doubled up on each (completely moveable LE and TE).

You'd also have to do something about directional stability and control, maybe having to have fins at each end? It'd be one ugly SoB whatever you did.

Even with active controls to make it flyable both ways, it'd be hard to avoid performance degradations, which I assume is included in "flies equally well"

One thing you could do is abandon the whole wing thing and go with some kind of rotorcraft. You get a degree of automatic symmetry fore/aft from the design that way. Hang a bubble underneath contra-rotating blades and maybe that's not far off the mark?

Interesting question!

[Mad (Flt) Scientist]

Only the hot air balloons would qualify. I very much doubt if a blimp flies as well backwards (the fins end up at the front, for one thing), and I'm pretty certain max rearwards speed on a Chinnok is lower than the max forward speed.

[The Otter's Pocket]

What about a ballon that could fly upside down?

[Global Pilot]

Doesn't the Harrier already do this?

[Mad (Flt) Scientist]

Not "equally well", I hope. Otherwise the decision to retire SHAR becomes eminently understandable.;)

[A Very Civil Pilot]

I'm sure this propably could


http://www.hotink.com/wacky/dastrdly/dast01.gif

[Lu Zuckerman]

To: jerrytug

I had a friend that built a large flying model. The wings and horizontal stabilizer were polyhedral and a Co2 motor powered the model. The construction was mainly of balsa and the model was covered in tissue paper.

Prior to launch the motor was propped over and started to run. However it was running backwards. When the model was launched into the wind it rose to about ten feet and slowly started to fly backwards and slowly picking up speed. The model rose to about 100 feet and disappeared over a large stand of trees. He never found the model.


:E :E

[ashjames]

it woulnt be easy because as you all know most of the lift comes from the front of the wing by increacing to air flow ect ect but flying backwards you would need a high angle of attack and a powerful moter as it would be highly ineficcent and require a lot of effort and now im going to stop because im sounding like a text book lol. :O

[Old Smokey]

Suggest you take up ornithology. Dragonflys can fly backwards at the same speed as they can fly forwards.

NASA, Boeing, Airbus etc. don't seem to be in any hurry to emulate this.

[Romeo Tango Alpha]

Well, kind of off topic, but I have HEARD of some aircraft either hovering or even flying backwards in a VERY strong headwind! I have HEARD stories of Tiger Moth pilots experiencing this (approach speed is 48 kts, so one must wonder WHY you would be out in the first place...)

The WW2 era German Fieseler Storch aircarft was and still is capable of decending vertically. During "show off" trials in the late 30's, before Adolf Hitler, a Storch was decended from 10,000 ft (probably it's service ceiling!) vertically, without moving forward or rearwards - just a slowm, gentle, vertical decent (with the aircraft in NORMAL attitude, just full flap, judicious use of power, and a strong enough headwind). Yes, the aircraft also DID fly backwards with a strong headwind, and full STOL configuration. Ground speed of NEGATIVE knots would be rather intriguing, but I am sure the novelty would wear off when you find it a tad hard to go where you wanted to!

:ok:

[Echo Zulu Yankee]

Guys,

Back in the day I once had an instructor who flew a Cessna 152 backwards. There was a strong headwind but nothing that one would consider "dangerous" for the type.

We were loosing about 100fpm and it was only a few seconds. Unfortunately it was silly young EzY who bet him a fiver he couldn't do it. :(

Blue side up! (Unless you are over the sea)

EzY

[simon brown]

???? how can you define whather a balloon flys backwards or forwards as it symmetrical. It displays no directional attributes apart from going up, being blown in a direction and then comes down.

[Onan the Clumsy]

Technically...

...A hot air baloon goes neither forwards nor backwards.


:8

[simon brown]

Onan...

good point , airspeed zero ...ground speed ..some:)

[1McLay]

Echo Zulu Yankee

You were moving backwards relative to the ground but if you could see the "air" you would still be moving forwards relative to it. i.e. the airflow is still travelling over the aircraft in the correct sense from leading to trailing edge. Nothing unusual about this is there???:D

1McLay

[cormacshaw]

Suggest you take up ornithology. Dragonflys can fly backwards at the same speed as they can fly forwards.

Sorry to be pedantic ...
Ornithology is the study of birds. Dragonflies, being insects, are of interest to entomologists.

In the matter of aircraft that fly equally well in all directions, isn't there a small unmanned military observation platform that is/was under development that is shaped something like a space capsule with a double rotor at the top. That would be capable of flying in any direction.

I can't see a fixed wing aircraft being capable of backward/forward flight. Threre would be the problem of transiting from one direction to another. Much easier to just turn!

[Onan the Clumsy]

Ornithology is the study of birds. Dragonflies, being insects, are of interest to entomologists. isn't that the study of words? :}

[InFinRetirement]

Saw a C17 reverse up the main at Farnboro' yesterday. Quite impressive. As for doing it in the air......................................:p

[Echo Zulu Yankee]

1McLay,

I Don't know about you but the company I work for designs its timetables (no jokes please) relative to the position on the ground rather than the air around the aircraft.

EzY

[Cool_Hand]

What about a flying saucer?

granted not many exist (if any) and I doubt that their ability to fly in all directions is based on aerodynamic efficiency more an anti gravity device but the idea is there. Wasn't there some form of prototype sometime around WWII that was disc shaped with four or five vertically mounted engines in the fuselage?

[ashjames]

i think its the americans that did it they found a way to make wire hover just by passing electricity through it highly dangerous but it worked

[jerrytug]

Thanks for all your interesting replies! The model won`t fly because of the angles of incidence being wrong for both directions,you would need a pilot on board (or a computer)to alter the angles at the moment of changing direction.
To change direction,then,you would pull up to vertical flight,and,just as the speed decayed to zero,alter the rigging angles to suit flight in the other direction,simple as that. Then quickly turn your seat 180 to face the duplicated controls at the other end of the cockpit,and ease out of the dive:D
Cool_Hand yes a frisbee comes closest! Any more suggestions for untried/impossible/totally unthinkable types of aircraft we could try? Thanks all,J