Anatolian Eagle' 19 - Thunder to roar in Turkey !

[CriticalThought]

Some fighter jets bleed energy faster than others and this depends mostly on aircraft design and engine performance. Russian fighters generally have better capability to bleed energy as compared to US fighters. And they regain it faster too. Cobra manoeuvre of Su series is a byproduct of this capability.

For readers who might not be familiar with the term, in fighter parlance when you say you're "bleeding energy" it essentially means that you're losing airspeed. In fighters we say that "speed is life". So losing airspeed, or bleeding energy, is generally, but not always, a bad thing.

There are a lot of ways to bleed energy. Some of the more obvious ones are:

1. Pulling back on the throttle to slow down. You might do this if you are approaching a merge with excess airspeed so that you can get closer to your best turning (cornering) speed in the event that you want to turn to engage. You may also do this to reduce your infra-red (IR) signature while you are approaching a merge with an opponent, thereby making it harder for him to get a head-on, IR-missile shot.
2. Climbing: If you have to achieve a high rate of climb to engage a target, you will most likely be doing this in full afterburner. However, even at this maximum thrust, if the distance to the target is short and the altitude difference is large, you may lose significant airspeed.
3. Sustained turning under high g: Anytime you turn under g, you increase drag. When maneuvering against an adversary, you will be max performing your jet using full afterburner while trying to manage your energy sensibly. You will trade altitude for airspeed while trying to force the opponent to fight your kind of fight. If you pull too hard and inappropriately, you will bleed too much energy and lose the advantage. Increased engine thrust and vectored thrust are some solutions to this source of energy bleed.
4. Rapid high alpha turns: Some planes can generate lots of nose authority (high turning rate) in a short period of time. You sometimes want to quickly point towards the target to either take a shot or to threaten that you are about to take one. A smart bandit will have to honor a properly timed and executed nose threat. This forces the bandit to turn harder into you and forces him to bleed energy. You may be doing this to actually take a shot or to slow him down, if your jet has an advantage at slower speeds. However, this high alpha turn also bleeds your energy.

Properly managing the aircraft's energy is a huge part of a fighter pilot's job.

What @messiach is saying, is that technically the excellence of an aircraft isn't in its ability to 'bleed energy'. It's the ability to convert P.E. to K.E. and vice versa.

Also, your 4 points above sound a bit amateurish. Lowering speed doesn't affect the frontal I.R. signature of an aircraft that is already running hot due to previous high speed. In a merge you employ BVRs and move into a turning pattern way before WVRs become relevant.

Your second point doesn't make a lot of sense.

Points 3 and 4, yes sometimes you want to use drag and/or a reduced lift coefficient to 'bleed energy' and that is a function of air breaks, geometry, and throttle. Thunder shouldn't have a problem in this area, but I have doubts when it tries to regain energy.

The Pugachev's Cobra doesn't bleed any energy. The aircraft moves mostly in a straight line.

@Oscar has energy management as his favorite topic.

 

[Armchair]

What saves us is India herself. The game of warfare stretches far beyond weapon systems. Operational preparedness, perseverance and discipline is what Indian Air Force lacks and they cannot buy it off the shelf.

@airomerix can we really depend on the enemy being incompetent in the future, or in your opinion, do you think we should go for another platform to counter the Rafale? If so, what platform would you suggest? F-16s seem out of the question, Eurofighter, Rafale too. J-10Cs are okay but the engine would be a big issue. Besides, PAF doesn't seem to be interested in the MiG-35 and Su-35, has never wanted Russian equipment.

 

[airomerix]

What @messiach is saying, is that technically the excellence of an aircraft isn't in its ability to 'bleed energy'. It's the ability to convert P.E. to K.E. and vice versa.

Also, your 4 points above sound a bit amateurish. Lowering speed doesn't affect the frontal I.R. signature of an aircraft that is already running hot due to previous high speed. In a merge you employ BVRs and move into a turning pattern way before WVRs become relevant.

Lower air speed (reducing engine GFR) does have a significant impact on the IR signature. Why? The air is temperature is already too low at altitudes we are talking. Its a matter of seconds before the IR signature disappears for most legacy radar's once the aircraft loses significant kinetic energy.

Your second point doesn't make a lot of sense.

Imagine an aircraft going vertical with full after burner. How much airspeed do you think it is gaining? A point comes when the aircraft starts to lose air speed or BLEED energy per say. Still I would suggest you to connect with a pilot on this. He might be able to explain you better in person since my literature is not making much sense to you.

The Pugachev's Cobra doesn't bleed any energy. The aircraft moves mostly in a straight line.

Oh no my friend. You should have taken a physics major.

I would suggest you to go through these slides.

 

[CriticalThought]

Lower air speed (reducing engine GFR) does have a significant impact on the IR signature. Why? The air is temperature is already too low at altitudes we are talking. Its a matter of seconds before the IR signature disappears for most legacy radar's once the aircraft loses significant kinetic energy.



Imagine an aircraft going vertical with full after burner. How much airspeed do you think it is gaining? A point comes when the aircraft starts to lose air speed or BLEED energy per say. Still I would suggest you to connect with a pilot on this. He might be able to explain you better in person since my literature is not making much sense to you.




Oh no my friend. You should have taken a physics major.

I would suggest you to go through these slides.

In those cold environments, the air is also rarer meaning less thermal conduction. That said, I haven't done the calculation using specific heat numbers for rarified air, so I won't argue the point. Modern aircrafts manage the heat signatures so the pilot doesn't have to waste mental capacity micro-managing the heat signature. That would be a pretty laughable thing to do.

A T/W ratio greater than one will always lead to acceleration. As the aircraft gains height, the effect of drag will only reduce. We are talking about aerodynamically optimized fighting machines not a hunk of iron.

This post computes the kinematics of the pugachev under the assumption of level flight:

https://defence.pk/pdf/threads/coas-witnesses-shaheen-vii-exercise-video.591425/page-4#post-11020377

And this video proves that altitude either remains constant, or actually increases. So much for bleeding energy

Before advising others on physics go read a textbook yourself. You are an amateur who mostly doesn't know what he is babbling about.

 

[airomerix]

In those cold environments, the air is also rarer meaning less thermal conduction. That said, I haven't done the calculation using specific heat numbers for rarified air, so I won't argue the point. Modern aircrafts manage the heat signatures so the pilot doesn't have to waste mental capacity micro-managing the heat signature. That would be a pretty laughable thing to do.

A T/W ratio greater than one will always lead to acceleration. As the aircraft gains height, the effect of drag will only reduce. We are talking about aerodynamically optimized fighting machines not a hunk of iron.

This post computes the kinematics of the pugachev under the assumption of level flight:

https://defence.pk/pdf/threads/coas-witnesses-shaheen-vii-exercise-video.591425/page-4#post-11020377

And this video proves that altitude either remains constant, or actually increases. So much for bleeding energy

Before advising others on physics go read a textbook yourself. You are an amateur who mostly doesn't know what he is babbling about.

Allow me to educate you.

Cobra manoeuvre is never sustained in a straight line. It simply doesnt have the ENERGY WHICH IS LOST IN SLOWING DOWN BELOW STALL SPEEDS. This sort of alpha manoeuvring is high AOA manoeuvre in which the aircraft first slows down (it never becomes still though) and IF IT INCREASES AOA, IT REQUIRES THRUST VECTORING TO VECTOR ITSELF INTO THE DESIRED DIRECTION OR IF IT PITCHES ITS NOSE DOWN, IT USES THE CHANGE IN P.E. TO CONVERT IN K.E.

Aap k liye asaan alfaaz mein. Cobra manoeuvre is a process in which the aircraft regains and bleeds energy repeatedly.

Before calling me amateur, you need to understand basics of kinematics which are taught in grade 7.

And guess what? Right now some of the gent's from one of our fighter squadron are smiling at your understanding about the matter. And your confidence. Amusing. Really.

@airomerix can we really depend on the enemy being incompetent in the future, or in your opinion, do you think we should go for another platform to counter the Rafale? If so, what platform would you suggest? F-16s seem out of the question, Eurofighter, Rafale too. J-10Cs are okay but the engine would be a big issue. Besides, PAF doesn't seem to be interested in the MiG-35 and Su-35, has never wanted Russian equipment.

F-16V is an adequate and a realistic answer to Rafale. Wait for Trump administration to depart. You'll see a change in Pakistan's standing. Pakistan has always suffered during republican rule. Pressler amendment was one of the products of republicans.

 

[Talon]

 

[SQ8]

@CriticalThought @airomerix

Quick end to the debate.
High speed creates friction(much as on the ground with rolling tires) between air- particles and the skin of the aircraft.
It does heat the air and the skin of the airframe as well which is why faster jets like the Mig-25 or SR-71 relied on titanium for their structures.. and also why the F-16(and other fighters with poly carbonate canopies- as they are the least resistant material to heat) are limited at different altitudes to different speeds.
Something called V-ne (never exceed) in aviation terms.

However, more often than not it still is the engine “exhaust” that is the hottest spot on an aircraft unless a pilot goes to idle - these can be simple images to more modern missiles are much more capable of actually seeing an IR pattern of the aircraft such as that from the Python 5/Barak/Spyder

Aim-9M/L

While at higher altitudes against colder air the effectiveness of reducing speed may be much less effective since the body of the airframe is still going to be hottest point around for miles - a low altitude environment with a relatively warm terrain and other heat sources present the reduced engine power and speed may fool third generation missile seekers such as the AIM-9L or the R-73.

This tactic however has no use against missiles such as the aforementioned Python or MICA, Asraam, 9x and others.

The PAF has a missile in service which has IR imaging falling between the 9M and the Python.

 

[Armchair]

F-16V is an adequate and a realistic answer to Rafale. Wait for Trump administration to depart. You'll see a change in Pakistan's standing. Pakistan has always suffered during republican rule. Pressler amendment was one of the products of republicans.

Thanks for the answer Airomerix. I really appreciate a former professional like you taking the time to explain these basic things to us fanboys here. The Clinton administration didn't give us F-16s either. So, if F-16s are out of the question, what would you suggest is going to work for us? Because it seems there is a round 2 coming up in a year or two.

What happens if India gets the Rafale and a reboot, and we are left waiting for F-16s that never come?

 

[TsAr]

F-16V is an adequate and a realistic answer to Rafale. Wait for Trump administration to depart. You'll see a change in Pakistan's standing. Pakistan has always suffered during republican rule. Pressler amendment was one of the products of republicans.

I see it the other way around. Republicans have been more closer to Pakistani govt, Reagan and Busy Jr were better then Clinton and Obama. Even Trump seems to be warming up to Pakistan. These days Democrats are more inclined towards India, just look at Hiliary and Kerry dancing on the big Indian wedding.

 

[CriticalThought]

Allow me to educate you.

Cobra manoeuvre is never sustained in a straight line. It simply doesnt have the ENERGY WHICH IS LOST IN SLOWING DOWN BELOW STALL SPEEDS. This sort of alpha manoeuvring is high AOA manoeuvre in which the aircraft first slows down (it never becomes still though) and IF IT INCREASES AOA, IT REQUIRES THRUST VECTORING TO VECTOR ITSELF INTO THE DESIRED DIRECTION OR IF IT PITCHES ITS NOSE DOWN, IT USES THE CHANGE IN P.E. TO CONVERT IN K.E.

Aap k liye asaan alfaaz mein. Cobra manoeuvre is a process in which the aircraft regains and bleeds energy repeatedly.

Before calling me amateur, you need to understand basics of kinematics which are taught in grade 7.

And guess what? Right now some of the gent's from one of our fighter squadron are smiling at your understanding about the matter. And your confidence. Amusing. Really.

You are making the mistake of applying the classical aerodynamic concept of high alpha to the pugachev. The aircraft doesn't act like an aerofoil generating lift. It acts more like a rocket under TVC. You are confusing the 360 degree yaw maneuver using TVC which bleeds energy with the pugachev which gains or retains energy.

 

[airomerix]

You are making the mistake of applying the classical aerodynamic concept of high alpha to the pugachev. The aircraft doesn't act like an aerofoil generating lift. It acts more like a rocket under TVC. You are confusing the 360 degree yaw maneuver using TVC which bleeds energy with the pugachev which gains or retains energy.

INCORRECT.

The kinetic energy is also bled in Pugachev manoeuvre. Especially from 50 to 90 degree AoA, most of the K.E is converted into P.E. Which means K.E. is bled off. Look at some diagram online. You'll understand it.

This is why I initially encouraged you to speak to pilots in person to understand this. These concepts are taught at FCU and Ops conversions.

 

[CriticalThought]

INCORRECT.

The kinetic energy is also bled in Pugachev manoeuvre. Especially from 50 to 90 degree AoA, most of the K.E is converted into P.E. Which means K.E. is bled off. Look at some diagram online. You'll understand it.

This is why I initially encouraged you to speak to pilots in person to understand this. These concepts are taught at FCU and Ops conversions.

If you have been following me, you will note that I have maintained a distinction between energy conversion and energy bleed. Energy conversion follows the law of conservation of energy and assumes ideal conditions with no friction. You bleed energy due to drag. This is lost as friction generating unwanted heat. A side effect being reduced speed hence reduced lift. Similarly, when a high AoA causes reduced lift, the effect is also termed 'energy bleed' although strictly speaking you end up trading off P.E. with K.E. if stall avoidance is not performed. But there is a time range where the increased AoA is causing your engine to lose thrust as well hence 'bleeding energy'. The pugachev suffers neither drag, nor high AoA since TVC is providing enough lift and the aircraft no longer follows the laws of aerodynamics.

@Oscar will keep me honest.

 

[airomerix]

If you have been following me, you will note that I have maintained a distinction between energy conversion and energy bleed. Energy conversion follows the law of conservation of energy and assumes ideal conditions with no friction. You bleed energy due to drag. This is lost as friction generating unwanted heat. A side effect being reduced speed hence reduced lift. Similarly, when a high AoA causes reduced lift, the effect is also termed 'energy bleed' although strictly speaking you end up trading off P.E. with K.E. if stall avoidance is not performed. But there is a time range where the increased AoA is causing your engine to lose thrust as well hence 'bleeding energy'. The pugachev suffers neither drag, nor high AoA since TVC is providing enough lift and the aircraft no longer follows the laws of aerodynamics.

@Oscar will keep me honest.

Finally you understand that energy loss is there in some form or another. Thank you.

 

[CriticalThought]

Finally you understand that energy loss is there in some form or another. Thank you.

I'll grant you this much. Whether the aircraft loses P.E. or not during the pugachev depends on how efficient the engine plus air intakes are. The video I posted shows Russian jets don't suffer. Your mileage may vary with other jets

 

[messiach]

Watson, there are lot of steps between the lip & the cup.

Some fighter jets bleed energy faster than others and this depends mostly on aircraft design and engine performance. Russian fighters generally have better capability to bleed energy as compared to US fighters. And they regain it faster too. Cobra manoeuvre of Su series is a byproduct of this capability.

For readers who might not be familiar with the term, in fighter parlance when you say you're "bleeding energy" it essentially means that you're losing airspeed. In fighters we say that "speed is life". So losing airspeed, or bleeding energy, is generally, but not always, a bad thing.

There are a lot of ways to bleed energy. Some of the more obvious ones are:

1. Pulling back on the throttle to slow down. You might do this if you are approaching a merge with excess airspeed so that you can get closer to your best turning (cornering) speed in the event that you want to turn to engage. You may also do this to reduce your infra-red (IR) signature while you are approaching a merge with an opponent, thereby making it harder for him to get a head-on, IR-missile shot.
2. Climbing: If you have to achieve a high rate of climb to engage a target, you will most likely be doing this in full afterburner. However, even at this maximum thrust, if the distance to the target is short and the altitude difference is large, you may lose significant airspeed.
3. Sustained turning under high g: Anytime you turn under g, you increase drag. When maneuvering against an adversary, you will be max performing your jet using full afterburner while trying to manage your energy sensibly. You will trade altitude for airspeed while trying to force the opponent to fight your kind of fight. If you pull too hard and inappropriately, you will bleed too much energy and lose the advantage. Increased engine thrust and vectored thrust are some solutions to this source of energy bleed.
4. Rapid high alpha turns: Some planes can generate lots of nose authority (high turning rate) in a short period of time. You sometimes want to quickly point towards the target to either take a shot or to threaten that you are about to take one. A smart bandit will have to honor a properly timed and executed nose threat. This forces the bandit to turn harder into you and forces him to bleed energy. You may be doing this to actually take a shot or to slow him down, if your jet has an advantage at slower speeds. However, this high alpha turn also bleeds your energy.

Properly managing the aircraft's energy is a huge part of a fighter pilot's job.