Comparison by Spurts

New and old developments in aviation technology.
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eloise

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Unread post02 Jan 2023, 07:19

sprstdlyscottsmn wrote:Current state of the comparison:
Radar/ECM/ECCM revamped to better utilize radar equation details from hornetfinn and garrya. Section 1 complete, I think, but Section 2 is not.
EO/IR undergoing revamp.
Possible Thrust revamp in the future based on f119doctor information but unlikely for current version.

It's been a long time since I've worked on this so I think I am going from the top down to make sure things are up to date so what I am putting up here is not final in any way.

I have been watching a lot of Growling siwinder lately. He uses F-14A and goes against many modern fighter from Su-30,Su-35, F-16C, F-35, Gripen
https://youtu.be/WTmJkpfUzcM
https://youtu.be/McYNLtFpsv8
https://youtu.be/SV1Vg3Pz0sI
https://youtu.be/Gyjow_kgFMo
One thing in particular that I noticed he mentioned is the use of flap. Once the flap are down, he can win the 2 circle fight against anyone. So why is that?. What make F-14A very capable with flap down eventhough it is quite heavy? and has low acceleration?.
One thing I find rather interesting is that he find F-35 and su-35 both very good in 1 circle fight, why is that?
It is also mentioned that in practicle, only the best F-14 pilot fly it with flap down, why is that?.
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Unread post02 Jan 2023, 10:55

Flap limit is 225knots. I could see it used in a slow 1 circle scissors type fight and possibly with rudder. In a 2 circle rate fight, still doubtful. No real life data exists for full flap deployment. Just ancedotes. And with flaps down, good luck recovering airspeed.

Youtube is about making money, I wouldn't take what GS says or does as gospel. He is not stupid, he knows what vids get watched the most. And more watched videos mean more money for him. DCS seems like a fun game, but it's not 100% reality. Even with certain available flight manuals/data they still can't get a jet to act completely as it did in real life.
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eloise

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Unread post02 Jan 2023, 11:08

I also have some question about the comparison of missiles:
462730A6-F3CB-46E7-B632-6240158B6BC8.jpeg

80CA7A76-CD61-4000-900A-B63D0F79F1CB.jpeg

7975637B-DB97-439F-A7E6-6823ADCE326F.jpeg


1-Why the available degree per second turn rate is highest at the terminal phase?, shouldn’t it be higher in mid cruising phase where missiles have a lot of speed?
2- Why the R-37 turn so bad? It has the lowest wing loading among the three of them, shouldn’t it turn very good ?
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eloise

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Unread post02 Jan 2023, 11:27

F-16ADF wrote:Flap limit is 225knots. I could see it used in a slow 1 circle scissors type fight and possibly with rudder. In a 2 circle rate fight, still doubtful. No real life data exists for full flap deployment. Just ancedotes. And with flaps down, good luck recovering airspeed.

I thought the maximum turn rate in the F-14 EM diagram is for the full flap deployment? Are they not?.
Anyway, here are some thing I recently learned about the BFM tactic and what they mean.

1 circle fight:
Everything starts with the “Blue” jet flying towards the “Red” in a neutral scenario (point A). At this point a fighter pilot already has in mind the “Game Plan”: the intention to enter into the fight and perform a “single circle” fight.
This type of fight is decided by the pilot who wants to use the excellent turning radius characteristics of his/her aircraft against a Red that is not as good in turn radius. Having said that, the pilot will tend to develop the fight upwards to reduce the airspeed to a minimum and, as a consequence, to reduce the turning radius. In addition, by setting a climbing maneuver at the time of the merge, the forward movement vector will also be reduced, thus increasing the chances of the pilot of finding himself/herself inside the turning radius of the defender.

As the fight develops (points C-D) the two aircraft will cross “nose to nose” in a maneuver called “flat scissors”: the aircraft that is capable of reaching first the smallest turning radius as well as the smallest forward movement will be able to obtain a shooting solution by pointing its nose at the other fighter (that in our case occurs at point E).

Now forget the points A-B-C-D-E because we are going to use the same to analyze the fight using, as an example, the F-16 turning performance tables below, where A, B, C would have a different meaning.

If you follow the red dotted line on the chart you can see that to get the best turn performance, the aircraft needs to reach the merge at around 430÷450 Kts/0.8 Mach. This would translate into a turning radius of 2,500 ft, a rate of 20 deg./sec and the ability to maneuver at 9G load factor (point A). Immediately after the merge, as we said, the pilot would start to turn with the purpose to achieve the minimum turn radius: in order to that he/she would pull Gs in the vertical, performing a maneuver to bring the aircraft at 300 kts/0.6 Mach: the pilot “aims” to reach point B of the chart, where the line that shows a minimum turning radius of 2,000 Ft is tangent to the line that represents the lower limit of the flight envelope of the aircraft. In point B, the aircraft can maintain a 18 degree turn rate and achieve the minimum turn rate. However these conditions are only sustainable for a moment so if the pilot wants to stay close to the minimum turn rate he/she would have to follow the blue line (the dotted one or a similar one – what is important is that from B to C the values on the x and y axis are not to the left of the continuous line that represents the boundary of the flight envelope) after merge and reduce speed and turn rate: at a 150 kts /0.3M the turn rate is 10 deg/sec and the minimim turn radius is below 2,000 feet. The aircraft is in point C where the flight envelope line intersects the curve for “SEP=0” (Specific Excess Power): it doesn’t need extra power to maintain speed and altitude while turning at the minimum turn radius. If the pilot is able to get to these points, he/she would be exploiting the aircraft at its best, as needed in a dogfight.



15190352-8DCB-4356-802E-564C34A2B418.png

F6889E07-1449-4ECB-80A6-EB523EF218BC.png

4651125B-875D-4A2B-98AF-FCBC24A5BAB9.png




2 circle fight:

We are always in the cockpit of the blue aircraft about to get into the merge, but this time we know that we can fight and win on the red aircraft if we go for a two-circle fight because our plane has a better turn rate than the enemy.

Returning now to our maneuver diagram, this time our target is to obtain the highest rate of turn (the above limit of the flight envelope): 20 deg/sec. Therefore, our merge speed should be 430÷450 Kts/0.8M and the most important thing is to be able to maintain this speed throughout the fight. At this speed maintaining 20 deg/sec is not possible because the aircraft is on SEP < 0 curve: to maintain this rate of turn we should lose 800ft/sec and that’s why generally all two circle fights develop downwards (fig. 5).

If we want to translate all this concept into a fight manoeuvres at the merge, we will simply roll the aircraft in a direction below the horizon, pull max Gs (we used to say “Lift Vector below the horizon”) continuing in a spiral and take advantage of the altitude (exchanging altitude for speed) in order to keep the speed as close as possible to our goal.

An important thing is worth highlighting: imagine you are flying the maneuver as show in fig. 5. You are turning at 9g to keep the tally on the red which has just passed at your 6 o’clock. Your head is turned backwards to keep the enemy insight (because “who loses sight loses the fight”) while you spiral towards the ground at the max performance, without looking at the HUD or flight instruments. It’s pretty obvious that fatigue can play a significant role here and this type of fight is often won by the fighter pilot who has the better G tolerance.

However, all these combat maneuvers often happen during the first few seconds of the fight (between 30 seconds and 1 minute into the fight); after hitting the 20 deg/sec (A), due to the progressive decrease of speed, we would be unable to maintain that turn rate. That’s why we should find a trade off that is called the “sustained speed”.

Let’s return to the turn performance diagram.

This time, after the merge and initial pull at 9g, our goal will be to use the altitude as much as we can and, when no altitude is available, keep the speed between 0.65M and 0.75M where we will touch the line with SEP=0, (B). From B, if we move along the SEP line between M0.65 and 0.75 (a range of speed called “sustained speed”) where we can fight without losing energy (speed or altitude or both ), turning at 14 deg/sec.

Normally you find yourself fighting at the “sustained speed” because you have reached the “combat floor” (and there’s no more altitude to trade): you can can “relax” so to speak and continue fighting at about 6 Gs.

0AF3C0E6-EDBF-4646-8663-0F1AB2F3E95F.png

F6A69C7E-2D27-489D-B4E0-06D054BE23D8.png

2B3CDFCB-6F78-406B-B50A-59FB88807B6A.png
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F-16ADF

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Unread post02 Jan 2023, 11:46

eloise wrote:
F-16ADF wrote:Flap limit is 225knots. I could see it used in a slow 1 circle scissors type fight and possibly with rudder. In a 2 circle rate fight, still doubtful. No real life data exists for full flap deployment. Just ancedotes. And with flaps down, good luck recovering airspeed.

I thought the maximum turn rate in the F-14 EM diagram is for the full flap deployment? Are they not?.
Anyway, here are some thing I recently learned about the BFM tactic and what they mean.

1 circle fight:
Everything starts with the “Blue” jet flying towards the “Red” in a neutral scenario (point A). At this point a fighter pilot already has in mind the “Game Plan”: the intention to enter into the fight and perform a “single circle” fight.
This type of fight is decided by the pilot who wants to use the excellent turning radius characteristics of his/her aircraft against a Red that is not as good in turn radius. Having said that, the pilot will tend to develop the fight upwards to reduce the airspeed to a minimum and, as a consequence, to reduce the turning radius. In addition, by setting a climbing maneuver at the time of the merge, the forward movement vector will also be reduced, thus increasing the chances of the pilot of finding himself/herself inside the turning radius of the defender.

As the fight develops (points C-D) the two aircraft will cross “nose to nose” in a maneuver called “flat scissors”: the aircraft that is capable of reaching first the smallest turning radius as well as the smallest forward movement will be able to obtain a shooting solution by pointing its nose at the other fighter (that in our case occurs at point E).

Now forget the points A-B-C-D-E because we are going to use the same to analyze the fight using, as an example, the F-16 turning performance tables below, where A, B, C would have a different meaning.

If you follow the red dotted line on the chart you can see that to get the best turn performance, the aircraft needs to reach the merge at around 430÷450 Kts/0.8 Mach. This would translate into a turning radius of 2,500 ft, a rate of 20 deg./sec and the ability to maneuver at 9G load factor (point A). Immediately after the merge, as we said, the pilot would start to turn with the purpose to achieve the minimum turn radius: in order to that he/she would pull Gs in the vertical, performing a maneuver to bring the aircraft at 300 kts/0.6 Mach: the pilot “aims” to reach point B of the chart, where the line that shows a minimum turning radius of 2,000 Ft is tangent to the line that represents the lower limit of the flight envelope of the aircraft. In point B, the aircraft can maintain a 18 degree turn rate and achieve the minimum turn rate. However these conditions are only sustainable for a moment so if the pilot wants to stay close to the minimum turn rate he/she would have to follow the blue line (the dotted one or a similar one – what is important is that from B to C the values on the x and y axis are not to the left of the continuous line that represents the boundary of the flight envelope) after merge and reduce speed and turn rate: at a 150 kts /0.3M the turn rate is 10 deg/sec and the minimim turn radius is below 2,000 feet. The aircraft is in point C where the flight envelope line intersects the curve for “SEP=0” (Specific Excess Power): it doesn’t need extra power to maintain speed and altitude while turning at the minimum turn radius. If the pilot is able to get to these points, he/she would be exploiting the aircraft at its best, as needed in a dogfight.



15190352-8DCB-4356-802E-564C34A2B418.png

F6889E07-1449-4ECB-80A6-EB523EF218BC.png

4651125B-875D-4A2B-98AF-FCBC24A5BAB9.png




2 circle fight:

We are always in the cockpit of the blue aircraft about to get into the merge, but this time we know that we can fight and win on the red aircraft if we go for a two-circle fight because our plane has a better turn rate than the enemy.

Returning now to our maneuver diagram, this time our target is to obtain the highest rate of turn (the above limit of the flight envelope): 20 deg/sec. Therefore, our merge speed should be 430÷450 Kts/0.8M and the most important thing is to be able to maintain this speed throughout the fight. At this speed maintaining 20 deg/sec is not possible because the aircraft is on SEP < 0 curve: to maintain this rate of turn we should lose 800ft/sec and that’s why generally all two circle fights develop downwards (fig. 5).

If we want to translate all this concept into a fight manoeuvres at the merge, we will simply roll the aircraft in a direction below the horizon, pull max Gs (we used to say “Lift Vector below the horizon”) continuing in a spiral and take advantage of the altitude (exchanging altitude for speed) in order to keep the speed as close as possible to our goal.

An important thing is worth highlighting: imagine you are flying the maneuver as show in fig. 5. You are turning at 9g to keep the tally on the red which has just passed at your 6 o’clock. Your head is turned backwards to keep the enemy insight (because “who loses sight loses the fight”) while you spiral towards the ground at the max performance, without looking at the HUD or flight instruments. It’s pretty obvious that fatigue can play a significant role here and this type of fight is often won by the fighter pilot who has the better G tolerance.

However, all these combat maneuvers often happen during the first few seconds of the fight (between 30 seconds and 1 minute into the fight); after hitting the 20 deg/sec (A), due to the progressive decrease of speed, we would be unable to maintain that turn rate. That’s why we should find a trade off that is called the “sustained speed”.

Let’s return to the turn performance diagram.

This time, after the merge and initial pull at 9g, our goal will be to use the altitude as much as we can and, when no altitude is available, keep the speed between 0.65M and 0.75M where we will touch the line with SEP=0, (B). From B, if we move along the SEP line between M0.65 and 0.75 (a range of speed called “sustained speed”) where we can fight without losing energy (speed or altitude or both ), turning at 14 deg/sec.

Normally you find yourself fighting at the “sustained speed” because you have reached the “combat floor” (and there’s no more altitude to trade): you can can “relax” so to speak and continue fighting at about 6 Gs.

0AF3C0E6-EDBF-4646-8663-0F1AB2F3E95F.png

F6A69C7E-2D27-489D-B4E0-06D054BE23D8.png

2B3CDFCB-6F78-406B-B50A-59FB88807B6A.png



F-14 Pilot talks about full flaps used in air combat training on aircrew interview: https://youtu.be/M2DUr0qhbdI?t=2873

The manual charts only give data for maneuvering devices 'not operating' and maneuvering devices 'on auto', they do not present any turn data for 'full flaps'.

Eloise, I don't want to go off topic. I will bring my responses to the F-16C vs F-14D thread later today aka viewtopic.php?f=30&t=28783&start=120
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Unread post02 Jan 2023, 16:05

eloise wrote:I also have some question about the comparison of missiles:

1-Why the available degree per second turn rate is highest at the terminal phase?, shouldn’t it be higher in mid cruising phase where missiles have a lot of speed?
2- Why the R-37 turn so bad? It has the lowest wing loading among the three of them, shouldn’t it turn very good ?


Available G is the answer for both.
I don't have a proper display for comparing two missiles on one image so we will have to work with this.
Untitled.png

Detail on question 1.
Once a vehicle is G-limited higher speeds decrease the turn rate.

Detail on question 2.
The R-37 is the faster missile and is G limited to 15G for most it's flight. Then it has gotten so slow that the available G goes down even farther which reduces turn rate.
The AIM-120D on the other hand flings itself into the upper atmosphere for long range intercepts because it has advanced enough guidance to know that it can spend time with a very low available G (remember the AIM-120D has the same motor as the AIM-120C-5 yet has a ~100% improved range, this is why). This gives it a steeper dive angle and the narrow body helps it maintain speed. Having more speed available in the thicker air gives higher available G.

Also, the West at large has learned that fins on a missile do more to reduce speed and range than they do to improve turning. Look at the ASRAAM and AIM-9X. Both very agile and tiny fins. Missile bodies make a ton of lift. By my model the R-37 has 22.99ft^2 lift area (Cl of each component times its area) and a burnout weight of 660 lb for a Lift Loading at burnout of 28.7lb/ft^2. The AIM-120D has 7.25ft^s of lift area and a burnout weight of 222 for a lift loading of 30.6 lb/ft^2. So the "Wing Loading" difference between the two is so small that the higher available G of the AMRAAM wins out.
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Unread post02 Jan 2023, 19:38

sprstdlyscottsmn wrote:Detail on question 1.
Once a vehicle is G-limited higher speeds decrease the turn rate.

How do you get the G-limit for these missiles?

sprstdlyscottsmn wrote:Detail on question 2.
The R-37 is the faster missile and is G limited to 15G for most it's flight. Then it has gotten so slow that the available G goes down even farther which reduces turn rate.
The AIM-120D on the other hand flings itself into the upper atmosphere for long range intercepts because it has advanced enough guidance to know that it can spend time with a very low available G (remember the AIM-120D has the same motor as the AIM-120C-5 yet has a ~100% improved range, this is why). This gives it a steeper dive angle and the narrow body helps it maintain speed. Having more speed available in the thicker air gives higher available G.


As far as I know, R-37 (RVV-BD) also climb upward, possibly to much higher altitude compared to AIM-120D due to its bigger motor. RVV-BD is actually quite new so its guidance shouldn’t be underestimated

sprstdlyscottsmn wrote:
Also, the West at large has learned that fins on a missile do more to reduce speed and range than they do to improve turning. Look at the ASRAAM and AIM-9X. Both very agile and tiny fins. Missile bodies make a ton of lift. By my model the R-37 has 22.99ft^2 lift area (Cl of each component times its area) and a burnout weight of 660 lb for a Lift Loading at burnout of 28.7lb/ft^2. The AIM-120D has 7.25ft^s of lift area and a burnout weight of 222 for a lift loading of 30.6 lb/ft^2. So the "Wing Loading" difference between the two is so small that the higher available G of the AMRAAM wins out.
.
I get that missile body can generate lift, but wouldn’t the tube body is a lot less efficient compared to the fin/wing in lift generation? especially at high altitude where the air is thin?. And wouldn’t the fact that R-37 is alot faster will also help it generate a lot more lift to turn?
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Unread post07 Jan 2023, 16:24

I found this today, pretty cool I think, and useful to understand the comparison
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Unread post07 Jan 2023, 18:12

eloise wrote:I found this today, pretty cool I think, and useful to understand the comparison


Probably very helpful since spurts did both!
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Unread post08 Jan 2023, 18:44

Revamped the R-37. Longer range and higher speed after calibrating with a more correct test launch parameter (MiG-31 combat cruise performance)
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Unread post09 Jan 2023, 02:47

sprstdlyscottsmn wrote:Revamped the R-37. Longer range and higher speed after calibrating with a more correct test launch parameter (MiG-31 combat cruise performance)

Recently R-37 is also used by Su-35 in Ukraine If I recalled correctly , I scored the longest kill distance
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Unread post09 Jan 2023, 11:00

I know it can be used by Su-35, that is why it is in my comparison at all, but I mistakenly assumed the test shot range was done from 2.5M at 75,000ft when the MiG-31 combat cruise is 2.35M at 60,000ft so I had to recalibrate.
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