Forum: General F-22A Raptor forum

I've noticed that on the F-22 raptor, that the TVC nozzles don't move individually, they only move up and down together. While this isn't to big of an issue, it would allows the aircraft to be out maneuvered by, say an SU-35 or PAK FA. I just thought that the F-22 could be brought up those maneuverability standards if both TVC nozzles moved independently. For example, the F-22 would be able to pull off a a barrel role faster if both nozzles moved in different directions (one up, one down). In not saying that the TVC nozzles should move in all directions, but just be able to move up and down individually rather than always having to move up and down together. What's your take, I feel as if this simple change could up the F-22's maneuverability a great deal.[/img]

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Independent movement of TVC is not going to make the F-22 do any maneuver any faster. At best, it would allow some minor roll control while in some specific post stall conditions where the other control surfaces aren't able to do so. There just isn't much lever arm there, and the alignment means that it can't contribute to yaw control the way that the Su-35's squed nozzles can.

If thrust vectoring control won't make it maneuver any faster, is there even a point to it? Is it even really worth it on the F-22 seeing it only seems like gives it the ability to gain and decrease its altitude faster.

zealousmule wrote:

If thrust vectoring control won't make it maneuver any faster, is there even a point to it? Is it even really worth it on the F-22 seeing it only seems like gives it the ability to gain and decrease its altitude faster.

Is this a serious post or are you just having fun with us?

bigjku wrote:

Is this a serious post or are you just having fun with us?

The answer is obvious.

Personally though as a MOD, I have to see how far this will go...

zealousmule wrote:

If thrust vectoring control won't make it maneuver any faster, is there even a point to it? Is it even really worth it on the F-22 seeing it only seems like gives it the ability to gain and decrease its altitude faster.

I normally don't feed the trolls, but since proof of that is still up in the air, I'll play for now.

In a way TVC does make the F-22 faster, or at least more efficient at high speeds. The TVC's main purposes are to reduce trim drag while supercruising and allow the F-22 to turn like a normal fighter would at much lower altitude. Slow speed maneuverability is just a bonus.

I had kind of had a brain fart moment when I posted this and shortly after I realized how stupid the topic actually was I wanted to get rid of it, however I'm unsure how to delete posts on this site, So I decided to just go along with it and play dumb. However now that I have gained the moderators attention I'm a bit concerned. I didn't mean to cause any trouble.

Just roll with it man.

The "I was unsure how to delete posts/went along with it and played dumb" thing rings hollow. Besides, how much trouble can you get in for trolling? It can't be any worse than being labeled a "newbie" here, can it?

FINAL WORD

Revel in your new-found roll here. There exists many a frustrated, angry, middle aged/middle manager on this site who's only reprieve is taking trolls to task after their wife makes them do the dishes after dinner. Don't worry about the mods, they're just doing their job. You being a whipping post for these frustrated middle management types though, serves an important purpose. Without you, there would surely be more workplace/domestic violence.

Salute...

count_to_10 wrote:

Independent movement of TVC is not going to make the F-22 do any maneuver any faster. At best, it would allow some minor roll control while in some specific post stall conditions where the other control surfaces aren't able to do so. There just isn't much lever arm there, and the alignment means that it can't contribute to yaw control the way that the Su-35's squed nozzles can.

There is also the wider position of the nozzles. The wider, the better effect on roll control.
So yes, it would make no sense to upgrade the F-22 nozzles. They are good as they are.
And the jet is exspensive and complex enough as it is.

mixelflick wrote:

Just roll with it man.

The "I was unsure how to delete posts/went along with it and played dumb" thing rings hollow. Besides, how much trouble can you get in for trolling? It can't be any worse than being labeled a "newbie" here, can it?

FINAL WORD

Revel in your new-found roll here. There exists many a frustrated, angry, middle aged/middle manager on this site who's only reprieve is taking trolls to task after their wife makes them do the dishes after dinner. Don't worry about the mods, they're just doing their job. You being a whipping post for these frustrated middle management types though, serves an important purpose. Without you, there would surely be more workplace/domestic violence.

Salute...

nice

Have you watched any aerial demonstrations by the F-22, and noticed an issue with maneuverability? You seem to have misconceptions about not only the role of thrust vectoring, but the trade offs each design has. To address the first issue, most of the turning performance is a result of the aerodynamic control surfaces, combined with available lift, and thrust. Thrust vectoring doesn't cause the plane to turn faster, it merely allows the nose of the plane to rotate faster, which if maintained results in loss of airspeed. Where it is useful, is under conditions where the control surfaces aren't (as) effective(i.e. high angles of attack/low airspeeds/high altitude). It also allows the plane to cruise supersonically, more efficiently, as control surfaces need not be utilized, to reduce trim drag. For whatever advantages you might gain from a 3D system, you lose in added weight, complexity, and higher radar/infrared signature. So... the initial premise is incorrect- there is no issue with the F-22's TVC. It achieved the goals that were desired.

The thrust vectoring is really for supersonic pitch control augmentation. Airshow benefits secondary. The YF-23 had respectably close pitch and roll performance without TVC, using larger all-moving control surfaces.

One of the ironies of the MiG-29 OVT is that the earlier MiG-29 was almost as agile in a dogfight, without 3D TVC, just had to be flown more aggressively, and with greater pilot skill. Departing controlled flight during ACM looks bad.

TVC is very good for regain flight after departure. It takes 1/10 of the time or altitude vs other jets without TVC. And on more than one occation, departured flight ends up with a crash and killed pilot.
Before i get the smear of "a pilot should never get into a departure flight" speach.. well sh*t often happens, both in training and in real situation.
Just the notion that a pilot know his jet can get out of a tricky situation with its TVC must be a good feeling.
Its very much about flight safty as well.. strange no one ever mention this..

@haavaria: You're forgetting a minor detail here. Even though there is a very small sample size of genuine departures from controlled flight in TVC aircraft, if TVC is working properly, the jet wont depart in the first place.

Someone who has more aerodynamic knowledge than I may wish to comment, but TVC doesn't work so well at low power settings, so for a TVC aided recovery, applying thrust could quite easily make the problem worse, and result in over-G'd aircraft during recovery. Raptor 91-4003 did temporarily depart controlled flight, with TVC active, and the jet Over-G'd due to a software glitch (11.7Gs according to reports), and basically, the jet received substantial damage, and never flew again.

My guess is that if a Su-30MKI Over-G'd then the result would be the same, even if it lands safely, the jet would never fly again.

I agree that 4th generation fighter don't crash often due to departure of flight and unrecovery spin. Mostly due to the reason when it happens they have altitude enough to recover. Which is all well and done. Nevertheless there has been crashes that could been avoided both in training and in real combat situation.
The whole TVC debate has been going on for years now. But now in 2013, the TVC nozzle designs have matured enough that makes the servicebility and cost at an accepteble level. There is very little weight penalty as well. So i think TVC for two engine fighter has a future.

I'm not saying it should be 3D or 2D or whatever, Just the flight safty issue alone should be enough to consider installing this.

Now regarding over G Manuveres due to pilot error, i don't really see this as an problem today, cause like the F-22, Su-35S and Pak-Fa are basicly designed from the start with TVC and it is integrated into the FCS, It has far more safty build-in prohibits. A pilot cant abuse the TVC in higher speed, cause the FCS will not engage the TVC more than just enough(trimming and such).

Forum: General F-22A Raptor forum

Issue with TVC on the F-22