Forum: F-35 versus XYZ

southernphantom wrote:

Please offer a source or technical reasoning for your comments. You are making inflammatory remarks without anything approaching justifications.

At high altitudes, low air density reduces the effectiveness of aerodynamic control surfaces.

Here's an argument....
In space, RCS (Reaction Control System) cold-gas thrusters are used to control a spacecraft's attitude and position, because aerodynamic control surfaces will be of little to no effectiveness. TVC offers a similar effect; control with thrust as opposed to with aerodynamic control surfaces. Therefore, it is more effective than only using elevators and ailerons to maneuver.

Im not making inflammatory remarks at all. Wrightwing claims "Incorrect." and provides arguments that is not in the context of maneuverability, which is why i respond with "Incorrect how?".

Wrightwings claim about trust vectoring being used to reduce trim drag is entirely correct. But it is irrelevant to the context of maneuverability.

Thrust vectoring is used to reduce trim drag in level flight. The way this is facilitated is by making subtle adjustments to the thrust vector, instead of using the control surfaces. When you maneover the situation is the opposite, you want to invoke the control surfaces as much as possible.

The reason thrust vectoring is close to useless for supersonic maneuvers is that the dynamic pressure is to high. It is however very useful for low-speed maneuvering, which was my original point in my response to shingen. (i.e my response saying "it is the other way around").

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pseudonymous wrote:

TV is being useful as a source of control at supersonic _and_ high altitude? Are you kidding?

pseudonymous wrote:

The reason thrust vectoring is close to useless for supersonic maneuvers is that the dynamic pressure is to high. It is however very useful for low-speed maneuvering, which was my original point in my response to shingen. (i.e my response saying "it is the other way around")

The original point was related supersonic/high altitude combinations, which you noted in your first post, but then in the next reply you dropped that and just said that qbar (dynamic pressure) was too high supersonic.
So, Mach 1.5 at 60k altitude: Dynamic pressure is ~238 psf. Doesn't sound "too high" does it?. That's because it's not. Same qbar (238) at 10k altitude? Comes out to Mach ~0.48 (267 Vcas). I'm guessing you wouldn't argue that 270 knots is "too fast" for TV.
It is true that vectoring is used less supersonic at lower altitudes, but that's not because it's "close to useless". It's mostly because it's just not needed.

pseudonymous wrote:

Thrust vectoring is used to reduce trim drag in level flight. The way this is facilitated is by making subtle adjustments to the thrust vector, instead of using the control surfaces. When you maneover the situation is the opposite, you want to invoke the control surfaces as much as possible.

Sorry, but that's just not how the system works. The control law doesn't really "care" (or even "know") whether you are trimmed up level flight or manuevering - all it sees is a command from the pilot, and a bunch of feedbacks from the airplane. It uses this information to come up with a single pitch "command" which then goes through a blender-type function (which has schedules based on things like speed, altitude, and AOA, as well as power setting) which splits up the command between vector angle and horizontal tail deflection. But, this blend never goes all the way to vectoring - you will never see a change to vector angle without an accompanying change in tail position.

Pseudonymous,

You don't write like an engineer or scientist or expert in another field.

So why do you come in here with a contentious voice to go after people who've been here a long time?

This is a good place with a lot of knowledgeable guys. No need for the argumentative tone of superiority. Especially if you're wrong one some points.

alloycowboy wrote:

There is no arguement that higher speed with higher altitude is a good way to defeat surface to air missiles. That is the SR-71's bread and butter. That is all very well and good so long as you have the fuel to Super Cruise. But as soon as you start flying the majority of your mission in the "Transonic Speed Range" and are only using Super Sonic Dash speed when needed then your better off optimizing the aircrafts engines and air inlets for the transonic range. Which is what they did on the F-35.

I have heard that the F-22 only has enough fuel to Super Cruise for approximately 50 minutes. So that is 25 minutes out and back.

That's X minutes at M1.8 though. I've never heard a 50 minute figure(Aviation Week said 41), though that might be possible. I think it's safe to say, that the F22 is capable of a lot more than 200nm while supercruising, whichever figure is correct. I'd also venture a guess that the official range figures are very conservative.

And now to get back on topic. The F-35 sensors/fusion, and reduced signature, will result in a first look first shoot advantage versus the EF. The Meteor won't change that situation. As for speed, both aircraft will require A/B to get to M1.6 or faster, so any advantages there would be fairly nominal. The F-35's low speed handling should be superior, especially combined with 360 deg spherical engagement ability. With the exception of a pure interception mission, I don't see too many decisive advantages for the EF.

What really matters?
Networking (F-35)
Sensors (F-35)
MMI (F-35)
Sig management (F-35)
Range/payload (F-35)
$ and will for upgrades (Hard to tell here, we're still not sure F-35 won't be cancelled)
Performance (Typhoon)

How in the world would the F-35 be canceled?

count to 10 - easily. If the program's costs continued to rise and the plane failed to deliver. Combine that with a budget crisis and the F-35 would be cancelled.

Really, the debate about Eurofighter vs. F-35 is too early to be decided. We don't know the full cost and capability of the F-35, too much of the plane's weapon testing and flight envelope have yet to be fully characterized. When that happens, we'll get a better chance of judging the relative strengths of the two aircraft.

Right now, I'd guess that you'd buy the F-35 if you want a generalist / ground attack focused aircraft. This would be a one stop shop for all around capability for a single airframe airfroce which expects to have to conduct ground attacks in the lifespan of the F-35.

If you're looking for an interceptor to conduct aerospace sovereignty missions, than the Eurofighter will probably be the better option for that. Its faster, built to do the intercept missions, and presumably will be cheaper to maintain. (no stealth coatings, less complex electronics, etc. )

The end decision will rely on the desired role for the aircraft and the final cost of the two planes. For all we know, when this really becomes an issue, in 8 years, the Eurofighter line may have already shut down.

Quote:

pseudonymous Banned

Yeesh, and all I did was ask the admins to check if it was that Avxva guy again. He really must have it in for the F-35 if he's making accounts months in advance in case he gets banned.

Highly motivated? Loopy? Paid?

arkadyrenko wrote:

count to 10 - easily. If the program's costs continued to rise and the plane failed to deliver. Combine that with a budget crisis and the F-35 would be cancelled.

We're already in a budget crisis, with known defense cuts, and the F-35 hasn't even had any total numbers cut, much less had the entire program threatened. The likelihood of that happening is approximately zero.

Quote:

Really, the debate about Eurofighter vs. F-35 is too early to be decided. We don't know the full cost and capability of the F-35, too much of the plane's weapon testing and flight envelope have yet to be fully characterized. When that happens, we'll get a better chance of judging the relative strengths of the two aircraft.

We have a pretty reasonable understanding of the F-35's performance/flying qualities, as well as systems performance.

Quote:

If you're looking for an interceptor to conduct aerospace sovereignty missions, than the Eurofighter will probably be the better option for that. Its faster, built to do the intercept missions, and presumably will be cheaper to maintain. (no stealth coatings, less complex electronics, etc. )

Faster is a pretty subjective term. How fast will the EF fly on an intercept mission, with tanks/missiles? AESA is lower maintenance than CAPTOR, and the stealth coatings on the F-35 are very low maintenance.

wrightwing - the JSF has been maintained at its present level because the Pentagon, and especially the USAF, have made it their No. 1 priority. But, the plan is the largest acquisition program at the Pentagon by a long shot, it will always have a target on it.

We don't know the maintenance and acquisition costs of the JSF. The F-22 maintenance costs were higher than anticipated and the JSF hasn't been produced and deployed in sufficient numbers to get a good idea. So we don't know what the maintenance costs of the JSF are. Furthermore, non-stealth coatings will be lower maintenance than stealth coatings. That's just a fact of life. The only question is the difference in costs.

Finally, intercept missions are not long range missions, at least for the European nations is responding to airspace violations. In that case, the plane won't be traveling very far and so it won't need large amounts of gas, etc. For those missions, the Eurofighter will probably be more optimized for the fast sprint out than JSF, which was designed for transonic flight. Remember, the Eurofighter has those recessed missile slots as well to reduce parasitic drag.

In air-to-air combat, the 5th gen always wins. F-35 is a th gen, so it wins.
Not that much too it. XD

arkadyrenko wrote:

wrightwing - the JSF has been maintained at its present level because the Pentagon, and especially the USAF, have made it their No. 1 priority. But, the plan is the largest acquisition program at the Pentagon by a long shot, it will always have a target on it.

It may see reduction in the total order. The program isn't going to be cancelled. That's just not going to happen.

Quote:

We don't know the maintenance and acquisition costs of the JSF. The F-22 maintenance costs were higher than anticipated and the JSF hasn't been produced and deployed in sufficient numbers to get a good idea. So we don't know what the maintenance costs of the JSF are. Furthermore, non-stealth coatings will be lower maintenance than stealth coatings. That's just a fact of life. The only question is the difference in costs.

The EF has 2 engines, and a MSA radar. Both of those will take more maintenance, than the F-35. It's coatings are designed to require almost no maintenance. Even if it ends up being more than a non-stealth coating, it'll be less than the engine/radar maintenance.

Quote:

Finally, intercept missions are not long range missions, at least for the European nations is responding to airspace violations. In that case, the plane won't be traveling very far and so it won't need large amounts of gas, etc. For those missions, the Eurofighter will probably be more optimized for the fast sprint out than JSF, which was designed for transonic flight. Remember, the Eurofighter has those recessed missile slots as well to reduce parasitic drag.

What speed do you imagine that the EF will be flying on these intercepts? Remember, the F-35 can fly M1.6+ with internally carried missles.

alloycowboy wrote:

There is no arguement that higher speed with higher altitude is a good way to defeat surface to air missiles. That is the SR-71's bread and butter. That is all very well and good so long as you have the fuel to Super Cruise. But as soon as you start flying the majority of your mission in the "Transonic Speed Range" and are only using Super Sonic Dash speed when needed then your better off optimizing the aircrafts engines and air inlets for the transonic range. Which is what they did on the F-35.

I have heard that the F-22 only has enough fuel to Super Cruise for approximately 50 minutes. So that is 25 minutes out and back.

It’s not just a good way to defeat SAMS but it’s even better in the A-A fight; some 7 times more survivable. But more to your point about optimum configuration, the problem isn’t in the inlet design but its engine cycle and the fact that the F-22 lost fuel during EMD to keep weight under control. That being said, despite the handicaps of being almost 14,000lbs heavier and having two engines the subsonic specific range is identical to the F-35s at roughly 0.10lb/nm or a combat radius of 590nm. Add in a 100nm supersonic segment and you can still go 460nm total. Again, not ideal but the tradeoffs are considered worth the price.

I think for the most part, whoever gets off the first shot wins in an A2A engagement. The F-35's stealth shaping, RAM coatings, internal weapons carriage and other RCS measures make it significantly harder to detect than the Typhoon. The F-35 can probably detect and engage the Typhoon first. Even if the Typhoon can defeat the BVR missile shot through maneuvering and ECM, it will be in a disadvantageous position should the F-35 pilot choose to pursue a WVR engagement.

Forum: F-35 versus XYZ

F-35 vs Eurofighter?