Aces High Bulletin Board
General Forums => Aircraft and Vehicles => Topic started by: AdmRose on August 29, 2005, 04:02:10 PM
-
Anyone ever hear of a German project called the Triflugel? Its basically a VTOL plane with three jet engines on rotors that spin around the axis of the plane giving it its lift and thrust. I wish I had a picture of it to post but information on Google is almost non-existant. It probably never made it out of the design stage.
-
Check out Luft46. http://www.luft46.com/fw/fwtrieb.html
-
(http://www.luft46.com/roart/rotrb-5.jpg)
Originally posted by AdmRose
It probably never made it out of the design stage.
It made it to wind tunnel testing.
-
yep thats the one, thanks
-
The design is sound, it should work just fine.
-
Until you landed. In a combat situation that plane would almost be impossible to land safely. US Navy had a similiar plane in the late '50s or early '60s that was going through a design process. In fact, it was based on that German plane but it was too difficult to land and in combat would virtually be impossible.
ack-ack
-
What plane would that be? If you're thinking of the Vertijet, then it is a completely different concept.
-
This is the plane I will assume Ack Ack is refering to
The Lockheed XFV-1
(http://www.fiddlersgreen.net/AC/aircraft/Lockheed-XFV/info/lock3.jpg)
http://www.fiddlersgreen.net/AC/aircraft/Lockheed-XFV/info/lock3.jpg (http://www.fiddlersgreen.net/AC/aircraft/Lockheed-XFV/info/lock3.jpg)
If not it is one that had problems that are being discussed here
-
That's more like it yes, but it is still not a rotorcraft like the German fighter. The German craft is actually a torqueless helicopter, not some sort of jumpjet or turboprop, and unless I'm mistaken helicopters fly and land just fine now.
(http://www.luft46.com/ghart/ghtrb-2.jpg)
-
Not on their tail, they don't! Pilot position in such an aircraft makes vertical landing a very challenging exercise.
PS: I think this thing was by far the most wacky tail-sitter design ever built though: http://jpcolliat.free.fr/xfv1/xfv1-8.htm
-
Originally posted by FalconSix
That's more like it yes, but it is still not a rotorcraft like the German fighter. The German craft is actually a torqueless helicopter, not some sort of jumpjet or turboprop, and unless I'm mistaken helicopters fly and land just fine now.
Agh?
Ever seen what happens to a 'copter that has lost its tail rotor? Spin like a top they do. The Fw a/c still has drag friction between the rotor and the fuselage > no 'frictionless' bearings it had.
The Lockheed XFV-1 has contra props > no torque.
-
the small levels of tourque can be countered by the ailerons. the tip-jet rotor system has been used successfully on several helo designs. the only reason they failed is because the ramjets that were used gobbled fuel as fast as a rocket engine.
-
Originally posted by MiloMorai
Agh?
Ever seen what happens to a 'copter that has lost its tail rotor? Spin like a top they do. The Fw a/c still has drag friction between the rotor and the fuselage > no 'frictionless' bearings it had.
A conventional Sikorsky type helicopter has engine torque, the Fw does not. Like SMIDSY says whatever friction torque there might be would easily be compensated for with the tail controls being directly in the rotor wash like that.
This thing flew:
(http://www.aerospaceweb.org/question/helicopters/tip-jet/hj1.jpg)
So did this:
(http://www.aerospaceweb.org/question/helicopters/tip-jet/hoe1.jpg)
And this:
(http://www.aerospaceweb.org/question/helicopters/tip-jet/crane.jpg)
And this:
(http://www.aerospaceweb.org/question/helicopters/tip-jet/djinn.jpg)
You'll notice MiloMorai that neither of these helicopters have tail rotors or any other obvious way of countering friction torque.
-
Originally posted by justin_g
Not on their tail, they don't! Pilot position in such an aircraft makes vertical landing a very challenging exercise.
None of the other "tail sitters" were stable in a hover like this Fw would (could) be. The Fw is simply a helicopter with the cockpit mounted on top of the rotor mast. All the other tail sitters had to be balanced on a column of jet or prop thrust much like the Harrier jump jet. The Fw otoh hangs from a rotor like a helicopter, and is therefore much more stable, like helicopters are.
-
Gee Falcon6, if those copters were so great, then why don't we 100s of them? Must have been great fliers.?:rolleyes:
You'll notice MiloMorai that neither of these helicopters have tail rotors or any other obvious way of countering friction torque.
Did you miss the exhaust pointing to the rear in the last 2 photos?
What if the Hiller looses rudder control? hello top.
"Though the concepts pioneered by Hiller in the US and Sud-Ouest in Europe offered promise in simplifying helicopter design, they never proved to be very successful. In addition to autorotation problems, the tip-jet design required rotor blades to be made stronger and heavier than conventional blades in order to support the heavy engines mounted on the tips. Both the hot-cycle and cold-jet techniques also proved to be less efficient than more typical helicopter designs. As a result, tip-jets have not resulted in good enough performance to justify replacing the tail rotor, so the idea has never become a truly commercial success in production helicopters"
And you want us to believe the Fw was a viable design.:eek:
-
Milo, please point out where it says they had control problems. Whether or not they were commercially successful compared to conventional helicopters is completely irrelevant.
-
Originally posted by MiloMorai
What if the Hiller looses rudder control? hello top.
What if the Sikorsky loses tail rotor control? Same difference.
-
Originally posted by MiloMorai
And you want us to believe the Fw was a viable design.:eek:
When did I say that? It's so like you to be disingenuous and put words in peoples mouths.
-
seen a thing on history channel other day, a russian plane/submarine thing....very different....dont think they ever actually made one though.
-
Originally posted by FalconSix
None of the other "tail sitters" were stable in a hover like this Fw would (could) be. The Fw is simply a helicopter with the cockpit mounted on top of the rotor mast. All the other tail sitters had to be balanced on a column of jet or prop thrust much like the Harrier jump jet. The Fw otoh hangs from a rotor like a helicopter, and is therefore much more stable, like helicopters are.
Which way does the pilot face when he tries to land that thing? Which way does a conventional helo pilot face when landing vertically? You have responded to a different issue than the one I mentioned...
-
There was a Secret Weapons of the Luftwaffe on the Hist ch a couple days ago. This plane and various others were shown in 3D flight and how they could have attacked bombers.
-
Milo, your question about why tip-jet copters are not seen was answered: They use ramjets at the blade tips. Ramjets are, basicly, afterburners minus the jet engine in front. They suck down fuel like it was being poured down a drain.
Other than that, they were torque-less. Bearing friction would try to spin the craft around a little, but is easily countered with aerodynamic controls.
The model you saw in the lower of Falcon's pictures was a little different, though. It had a conventional turbine engine, that was used as a 'gas producer'. Compressor bleed air was ducted to the blade-tips, rather than using ramjets. The end result was the same, though the difference in fuel usage between that and a ram-jet tipped model was negligable.
EDIT: Gah, I should of read more before opening my yap... This is what I get when posting when I feel like passing out from exhaustion :(
-
Whatever it turned out to be A Headon attack with it would make it a nice target for the opposite party.
what about the gyroscopic effect it wouldnt make it very manouvrable.
-
Originally posted by BUG_EAF322
Whatever it turned out to be A Headon attack with it would make it a nice target for the opposite party.
what about the gyroscopic effect it wouldnt make it very manouvrable.
One would hope its pilot wouldn't be so stupid to throw all the plane's advantages in speed out the window like that. At full speed a HO by this thing would be about a .5 second shot opportunity.
-
I've never understood why German aeronautical engineers, supposed to be in advance of everyone else on transsonic and supersonic aerodynamics, embraced such a silly concept.
The difficulties inherent in landing such an aircraft safely are indeed considerable and would probably make it far too dangerous for operational use.
But what really makes it so unlikely in my eyes is the use of what amounts to a large propeller with a significant amount of twist along its length, for high-speed flight. The supposed advantage was that the speed of the ramjet intakes could be constant by reducing rpm while forward speed increased. But the existing experience with conventional high-speed propellers suggests that the drag implications would have been horrific and the efficiency of the "wing" very poor; and the structural implications don't bear thinking about.
-
It's not a propeller. Its a rotary wing with variable pitch.
-
Hate to see what would happen if one of the engines or wing surfaces was damaged. Would make it damn near impossible to survive.
-
From what I have read the design was squelched because the average German pilot in 1945 would not have had the skill the land it.
As it has already been pointed out, the concept was sound enough that the USAAF attempted to put it into action.
An experienced pilot could have done it but they were in short supply.
I think this Focke Wulf design is the most interesting and feasible of the concepts:
http://www.luft46.com/fw/ta183-i.html
Combined with the X4 Missiles I think it would have been a formidiable opponent.
Saw an interesting program on the "Military Channel" about the He-162. According to that program, the Volksjager was actually a good performer for an early jet.
One pilot called it a "First Rate Combat Aircraft".
http://www.vectorsite.net/avhe162.html
I always thought it was a poor performer in addition to its technical problems which stemmed mostly from Germany's lack of resources.
All the best,
Crumpp
-
This was a terrific design, thats why you see them flying all over the place.
.....lol.:lol :lol :lol :lol
-
bail out = slice and dice
-
Originally posted by Crumpp
From what I have read the design was squelched because the average German pilot in 1945 would not have had the skill the land it.
As it has already been pointed out, the concept was sound enough that the USAAF attempted to put it into action.
An experienced pilot could have done it but they were in short supply.
I think this Focke Wulf design is the most interesting and feasible of the concepts:
http://www.luft46.com/fw/ta183-i.html
Combined with the X4 Missiles I think it would have been a formidiable opponent.
Saw an interesting program on the "Military Channel" about the He-162. According to that program, the Volksjager was actually a good performer for an early jet.
One pilot called it a "First Rate Combat Aircraft".
http://www.vectorsite.net/avhe162.html
I always thought it was a poor performer in addition to its technical problems which stemmed mostly from Germany's lack of resources.
All the best,
Crumpp
Read recent article in Wings based on US test pilots assessment, at Muroc. They thought the thing was a beast, hard to handle -- though (at work) cant remember what particular instability it had.
-
Originally posted by AdmRose
Anyone ever hear of a German project called the Triflugel? Its basically a VTOL plane with three jet engines on rotors that spin around the axis of the plane giving it its lift and thrust. I wish I had a picture of it to post but information on Google is almost non-existant. It probably never made it out of the design stage.
Major problem with rotor tip ramjet concept is endurance -- same thing tried with US helicopter -- the Hiller HJ1. It was noisy as heck, andThe voracious ramjets consumed an enormous amount of fuel. They gulped ten times the amount used by a piston engine of comparable output.
http://www.nasm.si.edu/research/aero/aircraft/hiller_hoe.htm
So, though the German plane looked cool and was sufficiently radical to impress the magical thinking of the Hitlerites, it would never have made a practical impact. At those fuel consumption rates, could it have even reached bombers? WOuld the extra fuel required reached diminishing returns from a weight/lift standpoint? The design looks like just another waste of engineering resources, not at all a wonder weapon...
-
so this thing is actually like takin the nose of a prop plane (with prop) putting cockpit on it, and at each prop end puttting a ramjet engine,
man id love to see that fly, or imagine like the stabilizing force in the plane-thing gettting shot, then ure spinning around like mach.6 or watever lol, WAAAAAAAAAAAAAAAAAAAAAAAAA
couldnt eject either ill bet
heh