VF-1 Fighter Mode Aerodynamics

[Kyp Durron]

I wasn't sure where to put this, so....

Has anyone here wondered whether or not the VF-1's fighter mode would be aerodynamically stable enough to actually fly in real life?

I honestly think it would be impossible without any tail planes, but I think the VF-0 would actually come closer to being able to fly with those huge canards on the bottom of the engine nacelles/legs.

Thoughts?

-Kyp

[Knight26]

Deja Vu all over again, we have had this discussion so many times, do a search next time.

[eugimon]

Thrust vectoring lets you do all sorts of crazy things.

[Vifam7]

I forget who said it - "Give me a big enough engine and I can make a brick fly"

[Ghost Train]

Two words: Animu Magic

[David Hingtgen]

Thrust vectoring lets you do all sorts of crazy things.

FAKE photo. (c'mon, look just above the base of the tail---it's obvious) (in addition to the photo's own caption)

[David Hingtgen]

I forget who said it - "Give me a big enough engine and I can make a brick fly"

Probably the F-4 Phantom's designer.

Also--Kyp, those aren't canards, they're ventral fins. They are only for yaw stability at high speeds/high alpha----they provide neither lift nor control. Canards are by definition at the front of the plane.

[VF5SS]

Stranger things have flown.

[eugimon]

The lack of a vertical tail is a 'shop job but not the lack of horizontal stabilizers which is what this thread is about.

Besides, the x-31 demonstrated it is feasible to go tailless.

Edited September 2, 2009 by eugimon

[Kyp Durron]

Probably the F-4 Phantom's designer.

Also--Kyp, those aren't canards, they're ventral fins. They are only for yaw stability at high speeds/high alpha----they provide neither lift nor control. Canards are by definition at the front of the plane.

Thanks for the correction, I hate it when other people don't use proper names, ESPECIALLY me.

And Knight26, I DID do a search, kthnx.

I was just looking at my three valks sitting here on the desk (1/60 V2 VF-1S, 1/72 VF25S, and 1/60 VF-0S), and started wondering if the VF-1 could actually fly in fighter mode or not. Of the three, I'd be the most surprised if the VF-25 COULDN'T fly...

-Kyp

[eugimon]

Thanks for the correction, I hate it when other people don't use proper names, ESPECIALLY me.

And Knight26, I DID do a search, kthnx.

I was just looking at my three valks sitting here on the desk (1/60 V2 VF-1S, 1/72 VF25S, and 1/60 VF-0S), and started wondering if the VF-1 could actually fly in fighter mode or not. Of the three, I'd be the most surprised if the VF-25 COULDN'T fly...

-Kyp

I'm sure they could. Macross planes are pretty conservative, it seems like, as far as fictional anime planes are concerned.

[Nied]

FAKE photo. (c'mon, look just above the base of the tail---it's obvious) (in addition to the photo's own caption)

It's a fake, but it's a fake straight from NASA who were going to fly the X-31 in that configuration before the funding fell through. The VF-1 would probably be unflyable without a good fly by wire system and thrust vectoring, but with those it shouldn't have much trouble (and the instability would make it incredibly manoeuvrable to boot).

[Hiryu]

There was a thread a while ago where someone actually built a radio control SV-51 and was able to get it flying fairly well.

[Kyp Durron]

There was a thread a while ago where someone actually built a radio control SV-51 and was able to get it flying fairly well.

Yes, I actually saw that video....that was really cool. As I recall, the builder actually got a call from The Hoary Froating Head himself after he was shown the video.

-Kyp

[-Snowblind-]

Stranger things have flown.

Even stranger things have flown... (it didn't fly well but it did get airborne)

(...and yes, I know it was a glider, but the point stands...)

Edited September 2, 2009 by -Snowblind-

[Ghost Train]

Yes, even stranger things have flown:

[Master Dex]

Yes, I actually saw that video....that was really cool. As I recall, the builder actually got a call from The Hoary Froating Head himself after he was shown the video.

-Kyp

Where can I see this video? If it is on youtube I'll look but a link would be nice.

EDIT: Nvm, I found it. Wasn't that hard.

Edited September 3, 2009 by Master Dex

[Mr March]

I appreciate more the discipline and consideration that went into the conceptual design of the VF-1 as a plausible aerodynamic craft more than speculation on it's actual real world capabilities. The VF-1 looks like it can fly, as much as any other jet fighter. It's a practical looking machine, as are most of the valkyries. It's one of the reasons I love the Macross designs. Still, I agree it would be even better if one could actually test whether or not a VF-1 could fly. Oh, to be filthy rich

[blacklotus]

Stranger things have flown.

Wow...Thanks for this nice bit of info. When I received a Hasegawa egg-plane SR71a, I thought it was just a cartoonised jet model kit. Today, I found out that these model kits are actually "re-designed" well-known jets from a real, flyable egg-shaped jet plane. XF-85 Goblin

Edited September 3, 2009 by blacklotus

[Master Dex]

I appreciate more the discipline and consideration that went into the conceptual design of the VF-1 as a plausible aerodynamic craft more than speculation on it's actual real world capabilities. The VF-1 looks like it can fly, as much as any other jet fighter. It's a practical looking machine, as are most of the valkyries. It's one of the reasons I love the Macross designs. Still, I agree it would be even better if one could actually test whether or not a VF-1 could fly. Oh, to be filthy rich

You and me both March, you and me both.

Though being an engineering student, if I had the time, I could try to figure out if the VF-1 was aerodynamically feasible. However I don't think I have had the high enough education to do that much, and besides... I'm an engineering student... I have no free time...

[Vifam7]

With enough engine and computing power, you can pretty much fly anything. In fact, most of today's fighter planes are aerodynamically unstable. Meaning that - without the engine and computer, a fighter like the F-16 is just a brick.

[eugimon]

With enough engine and computing power, you can pretty much fly anything. In fact, most of today's fighter planes are aerodynamically unstable. Meaning that - without the engine and computer, a fighter like the F-16 is just a brick.

Yup, look at the F-117... I remember hearing that if the computer ever goes out or goes on the fritz, there is no manual "kick it till it works" option, the pilot is just supposed to bail out.

[David Hingtgen]

Remember--a literal barn door will fly with proper alpha and thrust. Lift/drag ratio sucks, but it will produce lift.

[Thom]

A well-known nic of the F-117 (which is still a bomber!!!) is the 'Wobbly Goblin,' just for that inherit instability.

Though I just had a thought... dangerous - yes...

Since we know the vertical stabilizers are hinged for the inward swing and transformation, could they not also be canted outward during flight to act as elevons?

Edited September 3, 2009 by Thom

[SchizophrenicMC]

A well-known nic of the F-117 (which is still a bomber!!!) is the 'Wobbly Goblin,' just for that inherit instability.

Though I just had a thought... dangerous - yes...

Since we know the vertical stabilizers are hinged for the inward swing and transformation, could they not also be canted outward during flight to act as elevons?

Well, they are canted out to about the same extent as the F/A-18's vertical stabilizers.

Looking at the VF-1, it's completely capable of flight. The wing area is large enough to produce lift enough to keep it in the air, not to mention body lift. It has thrust vectoring paddles. (The nozzle is before the "feet", making them paddles) It has elevons. (Thom, that's the term for Ailerons that act as Elevators, as well. I can't remember what they call what you're saying.) It has a flight computer and a form of fly-by-wire.

I'd say it's theoretically as stable if not more so than some of the planes we're currently fielding or have used. For example, its inspiration, the F-14 Tomcat. It had straight-vertical elevators, tailerons mounted below the wing plane, and a large space between the nacelles and fuselage, what little of it there was. With all of these, it's no wonder the plane always flew pointed 2 or so degrees up at "level" flight.

[zenstudy]

Just wanted to chime in with my two cents here...

As it stands, I think the basic VF-1 layout would be fully flight capable, assuming we're using real-world materials and cleaning up the seam lines by doing away with the transformation capability (though that wouldn't be nearly as much fun ).

[ChronoReverse]

Even without tailplanes I don't see why it wouldn't be able to remain stable with the combination of tremendous available thrust, thrust vectoring and vernier jets along with the diagonal vertical stabilizers. I'm sure there's enough computer power on the VF-1 to make that stable =). After all, the same computers can stabilize the GERWALK mode.

[Nied]

Well, they are canted out to about the same extent as the F/A-18's vertical stabilizers.

Looking at the VF-1, it's completely capable of flight. The wing area is large enough to produce lift enough to keep it in the air, not to mention body lift. It has thrust vectoring paddles. (The nozzle is before the "feet", making them paddles) It has elevons. (Thom, that's the term for Ailerons that act as Elevators, as well. I can't remember what they call what you're saying.) It has a flight computer and a form of fly-by-wire.

I'd say it's theoretically as stable if not more so than some of the planes we're currently fielding or have used. For example, its inspiration, the F-14 Tomcat. It had straight-vertical elevators, tailerons mounted below the wing plane, and a large space between the nacelles and fuselage, what little of it there was. With all of these, it's no wonder the plane always flew pointed 2 or so degrees up at "level" flight.

The tails on the VF-1 are canted out but not enough to create anything more than a negligible amount of lift (for reference the canted tails on the new Silent Eagle mod of the F-15 create a few hundred pounds of lift on a 44,000 pound aircraft) and certainly not enough to allow for stable flight. The aircraft you mention (the F-14 and F/A-18) both have fairly large horizontal stabs to balance their CG (although the Hornet is still tail heavy enough that in needs a fly-by wire system for stability). Since the VF-1 lacks any kind of horizontal stabilizer (besides the very small of lift from the vertical tails and ventral fins) it would have to rely on a fly-by-wire system to maintain level flight.

[SchizophrenicMC]

The tails on the VF-1 are canted out but not enough to create anything more than a negligible amount of lift (for reference the canted tails on the new Silent Eagle mod of the F-15 create a few hundred pounds of lift on a 44,000 pound aircraft) and certainly not enough to allow for stable flight. The aircraft you mention (the F-14 and F/A-18) both have fairly large horizontal stabs to balance their CG (although the Hornet is still tail heavy enough that in needs a fly-by wire system for stability). Since the VF-1 lacks any kind of horizontal stabilizer (besides the very small of lift from the vertical tails and ventral fins) it would have to rely on a fly-by-wire system to maintain level flight.

Well, of course. I used the F-18 as an example, because we all know how little effect it has... Or we all should.

Also, if you're discounting the VF-1's wing area being capable of lifting the plane, you've forgotten body lift. The upper fuselage looks like it would be capable of adding another 30-40% of the total lift needed to keep the plane level. The wings provide the rest, and the thrust to weight ratio is much higher than is needed for anything else.

Inherently, any plane with this kind of setup is going to require Fly-By-Wire, but that's a given with any fighter these days.

I mean, the F-14 never could have been airborne, had it not used the system. (First mass-produced plane with FBW, another record of the Tomcat.)

[Knight26]

Well, of course. I used the F-18 as an example, because we all know how little effect it has... Or we all should.

Also, if you're discounting the VF-1's wing area being capable of lifting the plane, you've forgotten body lift. The upper fuselage looks like it would be capable of adding another 30-40% of the total lift needed to keep the plane level. The wings provide the rest, and the thrust to weight ratio is much higher than is needed for anything else.

Inherently, any plane with this kind of setup is going to require Fly-By-Wire, but that's a given with any fighter these days.

I mean, the F-14 never could have been airborne, had it not used the system. (First mass-produced plane with FBW, another record of the Tomcat.)

Wait what, ow ow ow, my brain hurts. The F-14 did not have a Fly By Wire control system, it was a purely analogue plane, where did you get that information? The first mass produced fighter with FBW was the F-16, that was why it was referred to as the electric jet. The F-14 was a marvelously aerodynamic aircraft, still is, but it was not some unstable POS, the only computer controlled control surface IIRC (DH correct me if I am wrong) were the glove vanes, but they were eliminated what it was determined that their use had no effect on how the aircraft handles during transition.

[taksraven]

Stranger things have flown.

Taksraven

Edited September 5, 2009 by taksraven

[Nied]

Well, of course. I used the F-18 as an example, because we all know how little effect it has... Or we all should.

Also, if you're discounting the VF-1's wing area being capable of lifting the plane, you've forgotten body lift. The upper fuselage looks like it would be capable of adding another 30-40% of the total lift needed to keep the plane level. The wings provide the rest, and the thrust to weight ratio is much higher than is needed for anything else.

It's not a matter of having enough lift it's a matter of where it's distributed. On the VF-1 nearly all the lift of the aircraft is concentrated on the wings, with no other surfaces to counter balance them, that means the slightest gust would send it flipping end over end if left to it's own devices. The only way for it to maintain level flight would be for the pilot, or a fly-by-wire flight control system, to constantly make control inputs to counter the natural instability of the design.

[SchizophrenicMC]

Wait what, ow ow ow, my brain hurts. The F-14 did not have a Fly By Wire control system, it was a purely analogue plane, where did you get that information? The first mass produced fighter with FBW was the F-16, that was why it was referred to as the electric jet. The F-14 was a marvelously aerodynamic aircraft, still is, but it was not some unstable POS, the only computer controlled control surface IIRC (DH correct me if I am wrong) were the glove vanes, but they were eliminated what it was determined that their use had no effect on how the aircraft handles during transition.

The control system was an Analog Fly By Wire system. It had issues with supersonic flight where the nose tended to pitch down. This is why it had the glove vanes to start with. It also had issues with flat spins due to single-engine compressor stalls at high speed. These issues led to them using the Flightcom to stabilize the plane enough where these were recoverable. Any plane designed to fly supersonic will have some inherent flight instability, just due to having to handle transonic airspeed.

However, the F-14 is especially so, due to its variable sweep wings. Those were completely computer controlled, although they could be manually adjusted. The thing wouldn't have been able to use anything but Fly By Wire to run. The hydraulic lines for hydromechanical flight would have all jammed up inside of the hinge point.

The F-16 was the first to use DIGITAL FBW, hence Electric Jet.

It's not a matter of having enough lift it's a matter of where it's distributed. On the VF-1 nearly all the lift of the aircraft is concentrated on the wings, with no other surfaces to counter balance them, that means the slightest gust would send it flipping end over end if left to it's own devices. The only way for it to maintain level flight would be for the pilot, or a fly-by-wire flight control system, to constantly make control inputs to counter the natural instability of the design.

Of course, but I'm just pointing out that the fuselage is a lifting body. With that percentage, it could act as a stabilizer to an extent. It pulls the lift closer to the center of gravity, reducing its ability to flip end over end in such cases, plus the FBW actively adjusts thrust vector so it doesn't.

[Knight26]

Quote your sources SMC. Yes the Wing Sweep was computer controlled, but that was it, and it was easily overrided, the other control surfaces were just good old hydraulically boosted. As for the glove vanes they were there for two reasons:

1) to destabilize the aircraft for supersonic MANEUVERING, otherwise the F-14 would not be able to pull hard maneuvers at high speed (with the wing swept)

2) to compensate during wing sweep for the change in CG, but only during transition.

The navy soon realized that neither was needed hence why all later F-14s had them bolted shut or in the case of the D model, removed (IIRC).

SO quote your source, I'll get the NATOPS and maintenance manual I was given during one of their last deployments, and the declassified tech manual that Bill Miller (grumman project pilot for the F-14) gave me.

[Nied]

Of course, but I'm just pointing out that the fuselage is a lifting body. With that percentage, it could act as a stabilizer to an extent. It pulls the lift closer to the center of gravity, reducing its ability to flip end over end in such cases, plus the FBW actively adjusts thrust vector so it doesn't.

1. You're greatly overestimating the amount of body lift the VF-1 could get, almost every area that creates lift on the F-14 hos something in the way or something to spoil the airflow on the VF-1 (the arms sit in the fuselage "tunnel" the wing gloves have their airflow disrupted by the upper intakes and the abrupt end they come to).

2. Even if they created any lift they would create the most at or near the lift for the wings so they couldn't provide any kind of stabilization.

3. And this is key: If it needs fly by wire to keep it in the air then it's not a stable design!