Forum: F-16 versus XYZ

Now I know, with its stealthy, one look, one shot, one kill thing, the F-22 can decimate nearly anything it comes up against. But, can the F-22, with its thrust vectoring, turn like a Viper?

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Good question. Since the wing won't shoulder the entire load, theoretically it can turn sharper than its structural limit would suggest. However, you probably won't get an answer here.

Note that the raptor maneuverability really shines at low speed, particularly near- and post-stall. There the Viper just can't hang with the big dog.

Why wouldn't I get an answer?

And does that mean the Viper has nothing over the Raptor? I mean, nothing?

See, the Eagle is faster than the Raptor, the Lightning (B-variant) has VTOL capability and (all versions) better air to ground capability. Is the Viper just TOTALLY outmached?

Let's talk about turning capability of a fighter airplane. Turning requires lift perpendicular to the flight path. That lift is provided by the combined wing / fuselage / tail (or canard) / and in some airplanes, thrust vectoring. Thrust vectoring does not provide lift. Quite the opposite, it provided a down force at the back of the airplane to rotate the nose up.

To develop significant turning lift the wing /fuselage / tail (or canard) must have an angle of attack and a significant airspeed. All this lift divided by the weight of the airplane is the load factor, sometimes called "g". At high airspeed the control power of the tail (or canard) is sufficient to push the airplane to the desired angle of attack, and obtain the desired lift, g, and turn rate. Note that thrust vectoring is not needed. At lower airspeeds, the tail (or canard) may not have sufficient power to rotate the airplane to the angle of attack needed. In this case, thrust vectoring is used to develop the angle of attack by pushing the aft end down. The wing /fuselage / tail (or canard) still provide all the lift for turning plus additional lift to overcome the down load from thrust vectoring.

To summarize, thrust vectoring adds to turning capability at low airspeeds but it does it with control power, not added lift. TV can point the airplane but cannot provide turning lift.

In comparing the Raptor and Viper, instantaneous turn capability at higher airspeeds is limited by load factor (g). If both airplanes are 9g, then their instantaneous turn capability is the same. With its higher thrust to weight and lower wing loading, the Raptor has higher sustained turn capability at most conditions. At lower airspeeds, the Raptor wins due to its higher angle of attack capability and TV. Remember, instantaneous turn means speed may drop during the turn and sustained turn means constant speed during the turn, with both turns at constant altitude.

The only way a Viper can beat a Raptor is in its air to ground weapon load capability. But the Raptor is not at this time intended to be a bomber anyway.

Well said. The F-22 also has a significant advantage in T/W ratio, acceleration (level, vertical, and unloaded) and climb rate, all due to the increased power of its twin F-119 engines. Also the F-22 has the further advantage that it will usually if not always enter the fight aerodynamically clean (no pylons or gas bags or anything to cause drag), even when carrying a full combat load of missiles.

In one exercise the F-22A went up against three F-16C's with HMDS and HOB "-9X" class missiles, a WVR fight. The F-22 killed the first two F-16's and was in the process of killing the third when the last F-16 used its HOB missile and fired almost simultaneously at the F-22. So all four aircraft were shot down.
This also adds to the voices that want the Sidewinder-9X with HMDS increased in priority, so it will be included in the upgrade, sooner than currently scheduled.

Adrian

Quote:

But, can the F-22, with its thrust vectoring, turn like a Viper?

Simple answer: significantly better.

avon1944 wrote:

In one exercise the F-22A went up against three F-16C's with HMDS and HOB "-9X" class missiles, a WVR fight. The F-22 killed the first two F-16's and was in the process of killing the third when the last F-16 used its HOB missile and fired almost simultaneously at the F-22. So all four aircraft were shot down.
This also adds to the voices that want the Sidewinder-9X with HMDS increased in priority, so it will be included in the upgrade, sooner than currently scheduled.

Adrian

I thought the Raptor wasnt certified to have the Helmet mounted sights yet.

avon1944 wrote:

In one exercise the F-22A went up against three F-16C's with HMDS and HOB "-9X" class missiles, a WVR fight. The F-22 killed the first two F-16's and was in the process of killing the third when the last F-16 used its HOB missile and fired almost simultaneously at the F-22. So all four aircraft were shot down.
This also adds to the voices that want the Sidewinder-9X with HMDS increased in priority, so it will be included in the upgrade, sooner than currently scheduled.

Pilotasso wrote:

I thought the Raptor wasnt certified to have the Helmet mounted sights yet.

The F-22A does not currently have "-9X" / HMDS but, it is one of the many upgrades scheduled. Unfortunately, the priority on this addition is not high.

Adrian

johnwill wrote:

With its higher thrust to weight and lower wing loading, the Raptor has higher sustained turn capability at most conditions.

Well, raw performance between the aircrafts always thrilld me the most. I do respect all involved law of physics like conclusions arising therefrom. I also know well tahat in discussed (quoted) case are many many varriables But... sometimes even if the pattern says one, the reality seem to say one.something Wink

Looking at numerous youtube videos regarding F-22's and F-16's so called 'max turns' or '9 g turns' from over two years I simply noticed.. that the sustained rate of turn means dgree per second is quite a bit but clear higher for the Viper! It lasts 16-20 seconds for a Viper to complete the turn average 18, while in case of the Raptor it's at least 20 seconds up to 24 seconds with 22 average to make a full 360degree turn. Also it seems that Raptor turns not only slower, but a bit wider than Viper equals better means smaller Viper's turn radius .

I guess tahat's because F-22's aerodynamics wasn't as like the Viper optimized for all the way pure energy-dogfighting especially at lower alts. May b higher things are diffrent but low Viper just kicks everybody's @$$!

Love the Viper! Pure fighterpilot’s fighter! not to mention the sexiest In Love

Cheers

Nope, this means that F-22 turned at higher speed. When you pull 9g at lower speeds you will turn faster and radius will also be smaller, but this is still 9g.

either way, the Viper turns the FASTER and TIGHTER sustained turn. And remember than while the Raptor has a lower wing loading it also has a worse aspect ratio so induced drag goes up.

Patriot wrote:

Looking at numerous youtube videos regarding F-22's and F-16's

Not thrust worthy. Video footage is hugely ambiguous.

sprstdlyscottsmn wrote:

either way, the Viper turns the FASTER and TIGHTER sustained turn. And remember than while the Raptor has a lower wing loading it also has a worse aspect ratio so induced drag goes up.

The F-22 might actually have a better aspect ratio. When wings are swept/tapered, you can't just compare span to chord. You need to look at the half chord line to get the average sweep and aspect ratio. The F-22's trailing edge taper probably lets it get a much lower sweep angle.

Aspect ratio is defined as span squared (44.5^2=1980) divided by reference wing area (840, 1980/840 is 2.37), when compared to a Vipers 3.0 it means that for any given LIFT COEFFICIENT the raptor makes 27% higher INDUCED DRAG COEFFICIENT. The Vipers higher wing loading (73 lb/ft^2 vs 87 lb/ft^, 19% higher) means that at any given speed or maneuver the Viper needs a 19% higher LIFT COEFFICIENT, resulting in 42% higher INDUCED DRAG COEFFICIENT. These two things average to the Viper having a 11% higher I.D.C. Now consider that the Raptors higher sweep angle (which lowers its parasite drag and wave drag, essential for high speed flight) shift the lift curve such that to attain any given lift coefficient it requires a higher angle of attack and thus increases the parasite drag when maneuvering (something the CAT I limiter on the Viper mitigates). Now while the viper makes 11% more lift drag coefficient the Raptor has 180% more area, so the raptor makes 152% more induced drag and has 140+% more static uninstalled thrust. With the increase in Parasite drag coefficient from increased AoA it is easy to see how at seal level with full internal fuel the Viper can have a better sustained turn rate. Not saying it necessarily does, but the basic math supports the theory. This of course all assumes same speed and same G.

Vtugimora wrote:

And does that mean the Viper has nothing over the Raptor? I mean, nothing?

The price.

Forum: F-16 versus XYZ

Viper vs Raptor: Maneuverabilty