The Real World capabilities of a VF-1 Valkyrie

[Valkyrie1981]

Been a Macross/ Robotech fan since I was a child, I entered the US Air Force right after High School and became a Crew Chief (Aircraft Maintenance Technician) This brought me into a crash course in Aerospace Engineering. Now I am not a Aerospace Engineer, however the VF-1 Valkyrie has two very big flaws. Wing Surface area, and total lack of elevators. (Not going to get into the insanity of the transformation of the leg hand off system)

Now the usual argument is that the VF-1 uses Thrust vectoring, however a lot of Air Forces have been playing around with that and one thing the NASA High Alpha Research Vehicle test program has shown is that it can not come close to replacing the elevators, they are better for enhancing an aircraft not replacing critical flight controls. This is why ALL aircraft that use Thrust Vectoring like the F-22, F-35, SU-35 have elevators. Thrust Vectoring with the VF-1's elevator tabs that are on the legs still will not provide the the maneuverability and control needed for the aircraft. Now I have seen posts referencing the F-117 Nighthawk as an example of a aircraft without elevators, but even if it was given a F "Fighter" moniker, the F-117 was a Bomber... It could only carry 2 bombs and that is it. It was never made to do anything like dogfight or dodge period. If it went to crazy on its angle of attack the wings would fall off, it was a Gen 1 Stealth plane and was built for one job sneak in drop some bombs, sneak out. Without elevators the VF-1 is highly unstable which isn't that big of an issue, but simply cant bank, turn, or pitch, well at all. Most Generation 4 Aircraft like F-16, F-18, or the SU-30 would fly circles around the VF-1 which has little to no maneuverability in fighter mode especially at low speed. I have seen people try and point to the McDonnell Douglas X-36 which yes is tailless but it had canards to act as elevators which once again does nothing to address the flaw. Even the most widely used tailless design aircraft in the world, the Dassault Mirage always had problems with pitch and canards were added in later version to solve the problem. And to simply say its Alien tech is a bit of a cheat.... Flying is a pretty straight forward concept, one that we humans have been improving since the creation of powered flight and for the VF-1 to be what it is, a Fighter Aircraft that can even dogfight it needs elevators. Also the aircraft was designed using the knowledge of the late 70's. If the VF-1 was designed in the era it was said to be made in... The VF-1 would be far more capable than what we have to work with.

The success of the F-22 is because it has 4 large empennage surfaces, and its Trapezoidal wing. Now the VF-1 look has been ingrained into the world but it would be interesting to see someone design any VF that doesn't have its roots in obsolete Gen 4 designs. Even the VF-25 is not very atmosphere friendly.

[JB0]

And to simply say its Alien tech is a bit of a cheat....

"Because overtech" IS a frustrating answer, but it's not one we need to trot out here. Attitude control thrusters are homegrown terran know-how that actually exist right now, though not typically on airplanes.

The VF-1 is studded with enough of them to orient freely in space, and at least some thrusters are capable of lifting the plane from a standstill on the ground at roughly 1G. One assumes they are adequate to compensate for the lack of elevators.

Ye olde space-age technology saves the day!

[Sildani]

The Variable Fighter Master File for the 25 also seems to say it uses its verniers to adjust the airflow around the 25's fuselage, thus making for an active airflow management system. With such a system, the actual aerodynamic merits of the airframe may not matter so much. Besides, it seems your typical Messiah/Lucifer spends 70% of its time in space anyway.

[JB0]

Also, I just realized this is your first post. Welcome to the board, hope we haven't scared you away already.

[Mr March]

If I recall correctly, years ago this issue came up and a former member on these forums once addressed it by describing the raw thrust/power vs. aerodynamics in regards to the Macross variable fighters. I wish I could remember it all, but I believe the gist of what he wrote was that even the lowly VF-1 Valkyrie possesses 3-4 times the thrust-to-weight performance of the best modern jet fighter craft and he argued with that much raw thrust at the pilot's command, all kinds of maneuvers using the thrust vectoring/vernier thrusters could be achieved above and beyond what a more aerodynamically superior fighter with conventional performance could hope to achieve. I don't know if that interpretation of the physics is actually correct, but at the time it sounded convincing to a layman like me

[Roy Focker]

Umm because it looks cool?

Seriously the VF-1 is designed to be visually appealing to a cartoon audience. Anime magic allows it to do cool stuff too.

[Valkyrie Driver]

Yay, another Airman! Looking at the toys, there are plenty of panel lines to suggest the Control surfaces are all there, sure we never see them move in show, but I think they have to be there, since it's easier and more aerodynamically sound than thrusters, though I imagine those can be used to increase performance. We also never really see the aircraft get preflighted, because that's boring. We want to see the dogfights, not all the tedious run up to them. There are also multipurpose control surfaces, Flaperons, Elevons, Ruddervators, you name it, that could contribute to flight control. It's possible that there might even be Active Aeroelastic Wings in some designs. Active airflow management, boundary layer control mechanisms, thrust vectoring and traditional flight surfaces could all work in concert to provide the extreme levels of maneuverability we see in variable fighters.

Welcome aboard!

[Valkyrie1981]

Thanks for all the welcomes, and responses. All sound reasonable, but the Anime is magic one.

Still would be pretty awesome to see a VF-1 based off of 5th Gen Fighters, which it would be based off of if designed in early 00's as it is in the series, than the 70's tech of 4Gen and 4Gen+ Technology.

[Seto Kaiba]

Now I am not a Aerospace Engineer, however the VF-1 Valkyrie has two very big flaws. Wing Surface area, and total lack of elevators. (Not going to get into the insanity of the transformation of the leg hand off system)

Welcome!

Also, I may have some unfortunate information WRT your perceived flaws in the VF-1 design.

For instance, per spec. the VF-1 Valkyrie actually has more wing area than the comparably-sized F-16 Fighting Falcon. It boasts a wing area of 32.8m² (353.1ft²), 17.7% more than the F-16's 27.87m² (300ft²).

Now the usual argument is that the VF-1 uses Thrust vectoring, however a lot of Air Forces have been playing around with that and one thing the NASA High Alpha Research Vehicle test program has shown is that it can not come close to replacing the elevators, they are better for enhancing an aircraft not replacing critical flight controls. This is why ALL aircraft that use Thrust Vectoring like the F-22, F-35, SU-35 have elevators.

Well, it has a couple different systems to supplement conventional control surfaces... but on the conventional side, those outward-canted stabilizers are basically ruddervators that, combined with the ventral fins, forms an X-tail. Ruddervators are a pretty common design feature on VFs in Macross (often variable cant).

On the less conventional side, there's also single-axis thrust vectoring (possibly verging into multi-axis thanks to a little side-to-side freedom in the nozzle/ankle), and also the usage of boundary layer control for attitude control assistance as well. Later VFs have vortex flow control systems as well.

Thanks for all the welcomes, and responses. All sound reasonable, but the Anime is magic one.

Still would be pretty awesome to see a VF-1 based off of 5th Gen Fighters, which it would be based off of if designed in early 00's as it is in the series, than the 70's tech of 4Gen and 4Gen+ Technology.

Kawamori did something along those lines for Character Model magazine... resulting in the SW-XA1 Schneeblume (think of a VF-1 with modern stealth aesthetics and internal ordinance bays).

[GuardianGrey]

I know that this was from the PSX video game, Macross: Do You Remember Love?

http://m.youtube.com/watch?v=R0P5e3Qt2lM

In between 0:45-0:55, Skull 010 & 011 (Max & Ichijo, I think) are lined up on the catapults on a carrier.

Skull 011 seems to do a quick check of all flight control surfaces before launching.

I will admit I am not sure if that is how they do it before taking off, though it is (I feel) a good example of said systems.

[Valkyrie Driver]

Here's the way it's done IRL:

Pretty accurate, though the Macross Opening looked considerably faster, Seems to me that a combat preflight would be quick though.

Edited May 14, 2015 by Valkyrie Driver

[David Hingtgen]

"Because overtech" IS a frustrating answer, but it's not one we need to trot out here. Attitude control thrusters are homegrown terran know-how that actually exist right now, though not typically on airplanes.

The VF-1 is studded with enough of them to orient freely in space, and at least some thrusters are capable of lifting the plane from a standstill on the ground at roughly 1G. One assumes they are adequate to compensate for the lack of elevators.

Ye olde space-age technology saves the day!

That was my thought---if the verniers have enough power to lift a valk up vertically off the ground, then they could surely create some extremely powerful attitude changes. It's the Harrier's puff-jet system, turned up to 11. Or 111.

And again---power/weight ratio. Valks have tons of power, and are light-weight. Super rough guesstimations:

If an F-22 has 40K thrust engines(x2), and max vector deflection downwards gives 8K(x2) thrust in that direction, that's 16,000lbs force moving a 65,000lb plane. It'll change direction of course, but not THAT fast.

But if a VF-1, with 55K thrust engines(x2), giving a proportional 11K(x2) downwards vectoring force, has 22,000lbs of force moving a 41,000lb plane----that's going to pivot it MUCH faster than the F-22, and that force would likely exceed the pitching force it'd get from having stabilators*. And all later valks have much better power/weight ratios.

*"elevator downforce" is a stat that I don't think I've ever seen---but I doubt many planes can generate downforce equal to half their own weight, from their tail. (of course, we also have to take into account the moment-arm for "effective force")

[M'Kyuun]

Welcome to the boards, Valkyrie1981. I was a bubblechaser in my AF days, and worked with alot of good crew dogs over the years. Appreciate your service.

As to the VF-1's flight effectiveness, the YF-23 is a good real world indicator that canted stabs and substantial thrust are enough to make a large fighter fly with impressive flight characteristics. As David pointed out, valks would have substantially greater thrust, verniers, variable wing geometry for high and low speed flight, and a bit of thrust vectoring due to the ankle joints. Although its stabs are small with conventional rudders, I've never really looked at the VF-1 thinking it wouldn't fly. OTOH, the whole leg detachment-reattachment dynamic for transitioning from fighter to battroid is more magical than unicorns farting rainbows. If any engineers are reading this thread, it'd be an interesting study to put the VF-1 in a simulator to test its flight characteristics.

We've put enough rockets and other flight capable objects in the air, and into space, to know anything can fly with enough thrust behind it. As an argument that even small flight surfaces can be effective, consider the JDAM. To see the tail unit, one wouldn't think it'd steer a 2K lb bullet so effectively, but it became the munition of choice, and changed the way we employ our bombers.

[vsim]

A while back when I was writing my VF-1 simulation. The main problems to note were that without an elevator, the VF-1 relies almost entirely on the thrust vectoring for pitch control. I forget the numbers, but when I tried to fly it with actuators that moved at the same rate as the ones on the F-22, it flew horribly. The control system I wrote could not move the thrust vectoring fast enough to keep good control over the aircraft, it was just not stable in any form. I eventually had to up the actuator rate and then it was happy (sorry I don't have numbers without looking into my source code up on sourceforge). But if I recall (it's been many years) I had to roughly double the actuator rate from the published numbers the F-22 uses, possibly higher. It was big problem.

It also made the weight and balance of the aircraft tricky because the wing sweep would move the aerodynamic center and center of mass around a fair bit. I did eventually manage to balance things out in all wing sweep configurations but it did require some fudging. Basically I redid calculations until I could come up with the best way to keep things realistic while still keeping the aerodynamic center and center of mass as close together as possible all the time.

The last thing I would note, which further points out how important the balancing and even the thrust vectoring actuators are, was trying to land the aircraft. In order to fly the aircraft slower, the engines have to be throttled back, which means less thrust. Less thrust also means less pitch authority, which means the thrust vectoring has to move even faster (often hitting limits) to try to keep the aircraft balanced and under control. A temporary solution I came up with for this was to deploy spoilers to increase the drag on the aircraft during landing, which means the engines are running at a higher thrust to maintain airspeed, but gives more pitch control. The other answer is to land faster, which is not unheard of, but usually not desirable .

So yes, in short, the VF-1 is feasible, with a little bit of alien technology in the form of very fast thrust vector actuators . I wish I had the time to revisit my project but I'm horrible with graphics and my area of interest is really in the modeling of the aircraft and control system itself.

I hope some of this makes sense.

[M'Kyuun]

Interesting observations, Vsim. Sounds like it's not a very stable platform even in normal flight, which would make it much more unstable during landing. And yeah, fast landings often lead to undesirable outcomes, the least of which are overheated brakes, which can end in brake explosion and fire, and subsequent loss of hydraulic pressure. Worst case, of course, is crashing.

As for your rapid action actuator to control vectoring, I offer a real world analogy: the B-1 is fitted with Structural Mode Control System (SMCS) vanes on either side of its nose for improved stability. The actuators in that system are capable of 4000 cycles per second. They are also 1970s technology. I've not worked on the 22 or the 35, but I can imagine the servoactuators being employed on these aircraft are likely superior in terms of force, sensitivity, and cyclic speed, and they are 1980s, early 90s tech. It's hard to imagine what the next gen fighter will be capable of, as it will likely approach what we now consider sci-fi. However, I'd say that the tech necessary to make a VF-1 inspired aircraft fly exists, although I'll concede that, for practicality, some design concessions, most notably the pitch controls, would be tweaked. Making it transform is probably another 150 years away. I'd love to be alive to see it, but it's enough to hope that it'll become an inspired reality. Maybe Kawamori's great, great, great, great grandchild will be a robotics engineer, and bring his/her ancestor's drawings to life. Cool to think about.

[David Hingtgen]

The last thing I would note, which further points out how important the balancing and even the thrust vectoring actuators are, was trying to land the aircraft. In order to fly the aircraft slower, the engines have to be throttled back, which means less thrust. Less thrust also means less pitch authority, which means the thrust vectoring has to move even faster (often hitting limits) to try to keep the aircraft balanced and under control. A temporary solution I came up with for this was to deploy spoilers to increase the drag on the aircraft during landing, which means the engines are running at a higher thrust to maintain airspeed, but gives more pitch control.

Both airliners and carrier-based planes often do this, to keep the engines spooled up for better response in case something happens. Fokker 28/100 and the Bae146 are the best examples I can think of. The final flap-setting on most every (non-Airbus)airliner exists almost solely for this reason---there is usually very little additional lift gained by going from "almost full" to "full" flaps---but there is more drag, so you can run the engines up further without speeding up. (the 727 and early 737 rarely land at max flap, they usually land at second-to last)

"Flaps 50" is basically "airbrake mode".

[SchizophrenicMC]

Let's also not forget that the VF-1 has a lot of vernier thrusters on its belly- apparently enough to give it VTOL capabilities in 1G environments. Employing these as a factor of the flight control system could compensate for reduced pitch authority of the thrust vectoring nozzles at low thrust during landing.

[David Hingtgen]

Let's also not forget that the VF-1 has a lot of vernier thrusters on its belly- apparently enough to give it VTOL capabilities in 1G environments. Employing these as a factor of the flight control system could compensate for reduced pitch authority of the thrust vectoring nozzles at low thrust during landing.

As I said before---the Harrier's puff-jets turned up to 11.

[JB0]

Or you could just land in GERWALK mode all the time. That'd be awesome.

[M'Kyuun]

Or you could just land in GERWALK mode all the time. That'd be awesome.

As long as you're landing on the deck in assigned parking with designs to relaunch soon. Fighter makes more sense, esp if you're hangaring; ceilings don't need to be as high, and fighter mode would be more conducive to routine maintenance, servicing, and munitions reloading. And, if you need the space, you can tow the fighter without cranking engines or APUs. I'd hate to be the crew chief of a pilot who always landed in GERWALK. Actually, it'd be a royal pain in the ass for all the maintenance folks, too, since everything would have to be done from stands. Dreadful things would eventually find their way into the bastard's helmet.

Sorry to spoil the coolness factor, but I can't help but see the situation from a maintainer's point of view.

Edit: I was just looking at my Arcadia 1/60 VF-1S looking for verniers on the legs that might produce the puff-jet exhaust we've been discussing, to no avail. I then consulted the original lineart in the Design Works, and I see no verniers on the naked valk to produce a vertical thrust. The FAST packs have them, however. Am I missing something on the bare valk that's not shown in original art or on the toy?

Edited May 21, 2015 by M'Kyuun

[JB0]

I said awesome, not practical.

It's implied there's more attitude thrusters than are usually drawn. The ones used for VTO showed up in DYRL, under the cockpit of all places.

[Sildani]

Overtechnology can have the verniers appear when they're needed and vanish when they're not. Aerodynamics, you know.

[JB0]

Makes sense. The thruster nozzles are probably made of a shape-memory alloy, so they can fold flat when not in use.

[vsim]

Haha, good points. The F-22 was originally designed without a horizontal stabilizer, but they ended up adding one later in the design. I suspect it was because they didn't want to rely on the thrust vectoring for 90+% of their pitch authority when the actuators aren't as fast as they'd like, although I don't know this for certain. I just base this on my own results using thrust vectoring.

And yes, thrusters could be used to augment the controls, but chances are they would only be used if the aircraft were not responding to the commands from the pilot "adequately", they still use some form of consumable and you wouldn't want to use them unnecessarily. Unless we just say "overtechnology" a few more times and then, hell just use the thrusters/verniers all the time!

M'Kyuun, I'm not trying to say the VF-1 is unstable in a bad way. For fighters, it is often desirable to be on the edge of stability as it will usually mean they can respond more quickly to pilot inputs, but it also means it very much relies on the control system of the aircraft to keep it from flying off when not commanded.

[JB0]

Well, the VFs have to carry enough consumable thruster fuel for a good engagement, because they operate in space where the thrusters aren't augmenting flaps. And by appearances, they fuel them space-ready even for ground-based airshows.

[Valkyrie Driver]

We should assume the presence of multi purpose control surfaces, augmented by the thrust vectoring, that would make the split more even, and add yet more control in atmosphere, also allowing the flight control system to make all of the necessary adjustments to stay in stable flight.

[JB0]

Basically, the tech is so advanced that anything you can think to do IRL is probably done on a Valk?

[M'Kyuun]

So enjoying this topic.

Overtech is a nice blanket, esp from a modern eye, to account for some of the VF-1's abilities. But I consider that HFH designed this back in the early 80's, when stealth was still in the black, and the F-15, F-16, F-18 and F-14 were the pinnacles of American fighter tech. Esp the 16, which owed its nimble performance to high instability, necessitating the air data computer to keep it in the air. It wasn't called 'lawn dart' for no reason; it was a widowmaker in its early days. Anyway, the VF-1, to my eye anyway, is a very anachronistic design in its fighter mode. There are no stealth features, no memory metals, no hideaway panels to preserve stealth...just a somewhat blocky, decidedly unstealthy but lovely 80's fighter with some interesting add-ons (the backpack) to facilitate the battroid mode. I don't think VTOL was in the original plan; Kawamori's art shows nothing of the sort, and I don't think that's a detail he missed. The FAST packs were his answer. Of course, in animation, anything can happen to serve the story at hand, so all sorts of modifications appear to give the thing abilities it originally didn't possess. They did it like crazy in Transformers.

Off topic: I'm also reminded of some of the observations when Macross: Zero came out, and the VF-0 was revealed. Of course, it has a design aesthetic incorporating stealth cues and, in many of its subtle details, looks exactly like what it is: an updated VF-1 design, contrarily presented as a predecessor to the same. But I remember alot of comments about how it looked like an old workhorse and such to try and justify the design. I could never reconcile the modern looking VF-0 as predating the VF-1...I can't unsee the modern touches. However, it looked amazing in those dogfighting scenes. And to kinda push this on topic again, how would the Zero fare as a viable aircraft, since it's larger and heavier than the VF-1, but with weaker engines? I don't see any VTOL verniers on it, either. Discuss!

[vsim]

First order comparison. It's bigger, heavier, less thrust, etc. and therefore slower/more sluggish than a VF-1.

I agree, it always bugged me a little that VF-0 looks more advanced than the VF-1. Maybe it could be argued that the VF-0 was designed as more of an experimental version, and the VF-1 is the mass produced version produced later. I just don't worry about it and I'm happy .

The VF-0 could still be made viable I'm sure, but there would have to be some of the same trickery as the VF-1 would benefit from. Same problems, just larger scale.

Which reminds me, the F-14 has glove vanes that pop out in high speed flight to shift the aerodynamic center forward when the wings are swept back. I'm fairly certain the VF-1 (? VF-0 as well?) does not have these, can anyone verify that? I can't remember whether it did or not, lol.

F-14 Glove Vanes:

[Nekko Basara]

I'm not the expert some folks here are, but I've never seen glove vanes on a VF-1. It might be worth noting that they were generally disabled as unnecessary on the F-14A, and were omitted from the F-14D entirely. That may have some relevance to discussion of how troublesome the shifting of center of gravity and center of lift with wing sweep are. It apparently didn't matter as much in practice as the Tomcat's designers thought it would.

[Sildani]

I don't think the Tornado has any equivalents either. Nor the Backfire, Blackjack, or Fencer. I suppose the CG difficulties were overcome in other ways.

[M'Kyuun]

Neither the F-111 nor the B-1B have glove vanes. The B-1 uses internal fuel transfer to maintain CG, and strategic pivot point positioning helps the F-111.

After consulting the original VF-1 lineart, which is more prolific and detail intensive than any other valk in the Design Works, there is no attention given to nor indication of glove vanes. That's about as authoritative as you can get.

[Valkyrie Driver]

I looked into the F-14, and it brought me back to Control surfaces. The F-14 has tailerons (the stabs move as elevators and ailerons), and uses spoilers for low speed roll control. Looking at the VF-1 (and all subsequent VF's) the thrust vectoring could be used in much the same way as the F-14's tailerons, and using spoilers to assist in roll control at low speeds.

[M'Kyuun]

RC VF-1 in action. Notice the really large vertical stabs.

Edited May 25, 2015 by M'Kyuun

[vsim]

Yeah, I didn't think the VF-1 had the glove vanes. And for a vehicle with a horizontal stab, I can definitely see that they would not be as necessary, but on the VF-1 some type of control of the aerodynamic center would certainly help. The other thing that helps the VF-1 some in this regard is the fact that the wings don't carry any type of fuel, so the movement of the center of mass and aerodynamic center can be tuned and not dependent on how much fuel is left.

Thrust vectoring for pitch control is sort of like balancing a broomstick on your hand, it can get away from you very quickly if you can't react fast enough to keep up.

On a side note, why in the hell is the thrust vectoring for the VF-117 mostly work in the lateral direction (sideways)?! This always has kind of bugged me. It's entirely physically possible, but ....weird, I can't think of many good arguments for it, especially in atmospheric flight.