# Why maneuverability and top speed are still issues in 5th generation air superiority fighter jets [duplicate]

In a previous question someone asked why do modern fighter jet speeds decrease compared to older fighter jets, and someone hinted that nowadays top speed is not a factor considering modern rockets which will anyway exceed the maximum G forces that a human body can withstand.

Now, in the F-22 vs T-50 comparisons many hint at superior maneuverability and top speeds of the Russian T-50 design.

Shouldn't modern fighter jets be all about BVR (beyond visual range) capabilities and thus speeds and maneuverability be "surpassed".

I imagine modern fighter jets to be basically bricks in the air with a lot of high tech long distance warfare technology.

• Your imagination is incorrect. How far away would two stealthy jets be when they detect each other? – Deer Hunter Nov 1 '15 at 13:52
• Also a consideration: what kind of fighter jet are we discussing here? Built for what purpose? – CGCampbell Nov 1 '15 at 15:44
• I asked with 5th generation fighter jets in mind and with air superiority in mind. Whatever distance they are I suspect a "5th" generation air to air missile will be hard to be avoided by a human manned aircraft. – dendini Nov 1 '15 at 20:07

Fighter jets are not bricks with powerful radar and long range missiles. BVR combat is an extremely complex affair conceptually, operationally and technologically.

• For BVR combat to be initiated, the enemy aircraft should first be identified and sorted as a threat. However, assuming that both have similar radars, the inverse square law ($S \ \propto \ \frac{1}{R^{2}}$) means that you are exposing yourself to the enemy before identifying him. Combat between two stealth aircraft (F-22 vs T-50) is not unlike two men with a gun and flashlight in a dark room, as someone noted. The first one to switch on the radar is actually at a disadvantage and against a highly trained enemy, possibly suicidal. Also, let's not forget SAM ARM missiles that can home on the aircraft radars.

• Though the number of aircraft shot down by radar guided missiles (as opposed to IR missiles, which are usually fired WVR) have risen significantly both in numbers and also as a percentage (of total aircraft shot down), the probability of achieving a kill by a BVR missile is still uncomfortably low. For example, the following table shows the ratio of 'kills' by radar guided missiles post WWII.

Table from Promise and Reality: Beyond Visual Range (BVR) Air-To-Air Combat by Lt Col Patrick Higby, USAF

• The high percentage of BVR kills in Gulf war is basically due to two factors- AWACS and IFF(Non-Cooperative Target Recognition (NCTR) system), which gave sufficient confidence to permit BVR shots. It is highly unlikely that such a superiority level and confidence is available in case of war between two peers.

• Another thing is that barely any of the BVR shots are fired head on due to the high closing speeds. So in all probability, you have to maneuver yourself in a position where a tail (or an above) shot is possible.

• Also, if some missile is fired at you, speed and maneuverability are critical to carry out evasive maneuvers.

• Most of the combat aircraft use in present day has nothing to do about air superiority. They are mostly used as precision guided bomb trucks. Optimizing fighters for BVR combat sacrificing other parameters is, at the least, foolhardy.

So far, the most important contributors to BVR victories (in Gulf War, for example) are not due to some inherently superior technology, but due to human factors- pilot skill and opponent's weakness. It is potentially catastrophic to generalize the doctrine against a near-peer opponent.

• Good answer, still your table of BVR shots is 90's history, I was asking with 5th generation fighter jets and air superiority in mind. I think a lot has changed in the last years... I'll update my question to underline that. – dendini Nov 1 '15 at 20:04
• @dendini, what makes you think that a lot has changed to improve the chance of BVR kill? If anything, stealth aircraft are harder for the BVR missiles to lock on. – Jan Hudec Nov 1 '15 at 21:38

Modern fighter aircraft will be in service for at least 20, if not 40 years. This means they will see several updates, will carry several generations of weapons and be used in unexpected, unforeseen scenarios.

Already today many combat aircraft designs are older than the pilots flying them. The relentless increase of weapon systems costs will mean that in future a smaller number of designs need to cover all demands, and do so for many more years with fewer platforms. Not giving those designs all capabilities which we can put into them will translate into a platform with clearly identifiable soft spots, and hostile weapon systems and tactics will try to exploit them to their advantage.

Neglecting one of top speed, range, endurance, maneuverability, stealth or survivability will create a deadly weakness - maybe not within the first years those designs are fielded, but certainly for the majority of their lifetimes. Just consider the variety of tasks for a modern air superiority fighter:

• Intercept intruders. What is a fighter worth that cannot climb up to an unknown threat in a hurry? With fewer aircraft around, the likely intercept distance will go up, too.
• Long-range strike. Let's face it, the F-15 and F-16 are used for strike missions a lot today. You have much more freedom in picking your base if the aircraft's range does't restrict you.
• Combat air patrol. You need to establish permanent air superiority with as few platforms as possible. This needs endurance.
• Dogfighting. In a low-intensity conflict the political directive is to visually identify the target in order to avoid embarrassing mistakes. You cannot always count on using BVR missiles.

The old black-and-white world of the Cold War has changed into a multi-faceted world with many shades of grey, and needs versatile, flexible platforms.

It is a legitimate question that is difficult to answer because there are little to no examples from actual warfare. What would happen when two pilots fight for real with \$100 million aircraft on the line? It's hard to answer this definitively.

A lot will depend on the combat context. Are we fighting over the ocean or in a big mountain range, like the Caucasus or Carpathian mountains? If it is useful for an aircraft to hide in the mountains, maneuverability can be extremely important.

Speed is always very important because more speed increases the ability of the pilot to position the aircraft in a favorable location preliminary to the engagement. In exercises this matters less because both aircraft are placed in neutral or "equal" positions. In real combat usually positioning is unequal and whoever can get to the good spot first will have an advantage, often a decisive advantage.

Firing a missile at someone you cannot see is problematic because how do you know they are the enemy? Also, they can see your missile on radar way ahead of time and evade it unless you get sufficiently close before firing. In real combat the enemy will not loiter out in the middle of the wild blue wonder just waiting for you to come and shoot at them. They will always position themselves in a secure location, such as close to the ground, where you can't see them.

The defender will have a huge advantage if they have ground radar or an aerial radar, such as one on an aerostat, because they will see you coming and they can position their aircraft to ambush you. This is why SEAD is so important. Against any opponent that has anywhere near your capability, it is suicidal to act due to the advantage fixed radar will provide. In a future war it is likely that specialized antennas will be made that are distributed and difficult to destroy. This will make aerial attacks on foreign soil very difficult, unless the enemy has primitive technology.

BVR Issues

As far as the design of the T-50 is concerned, the focus on maneuverability is reasonable, especially for a defensive, air superiority fighter. As far as aircraft radar is concerned, be aware that it can only see (at best) in an 120-degree cone directly in front of the aircraft and if you use it, you light yourself up like a Christmas tree and everybody will know exactly where you are. Therefore, in a real war aircraft will, in many situations, not even use their radar, because it will give away their position, thereby allowing an enemy to pop up behind them and shoot.