F-35 vs Mig-31 + A-50

The F-35 compared with other modern jets.
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by hornetfinn » 11 Aug 2015, 12:57

sergei wrote:The debate boiled down to a spherical horse in a vacuum.


That's how all of these X vs Y debates always are, what's your point?


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by eloise » 11 Aug 2015, 15:21

hornetfinn wrote:I definitely agree that missiles designed for high altitude operations against high altitude aircraft benefit from having larger control surfaces. However, it's noticeable that older missiles did have much larger wings and fins even if they were designed for low altitude. Missiles like Roland, Crotale and Sea Cat for example had huge wing/fins while max altitude was about 15,000ft . Modern similar missiles have very small wings/fins while being able to maneuver several times harder even at long ranges and having much superior range and altitude. So comparing modern missiles to old ones (like R-40) is not going to give any answers about altitude limitations of modern missiles. Especially since modern medium/long range AAMs are much more sophisticated guidance systems which means the engagement geometry is going to be totally different. Old semi-active missiles were going in very straight trajectory towards their targets which is very inefficient compared to modern missile trajectories, especially active radar guided with datalink midcourse updates which can use much more optimum engagement profiles.

in my opinion many older missiles have big wing because they need enough lift to compensate for their low speed ( either due to inefficient profile or the use of full boost motor)
Also even these missiles listed above still have more lift at their max altitude than Aim-120 at 70K ft
For example :
Roland maximum speed is mach 1.6 , maximum altitude is 5500 meters ( 18000 feet), at 18000 feet mach 1.6 ground speed is about 747 kts ( 1383 km/h) EAS

Crotale maximum speed is mach 2.3, maximum altitude is 5500 meters ( 18000 feet) , at 18000 feet mach 2.3 ground speed is about 1075 kts ( 1990 km/h) EAS

Sea Cat maximum speed is mach 0.8, maximum altitude is 5000 meters ( 16404 feet) , at 16000 feet mach 0.8 ground speed is about 389 kts ( 720 km/h) EAS

R-40 moving at mach 5 ground speed will have 691 kts ( 1281 km/h) EAS at 70000 feet

at 70K feet AIM-120 , Meteor moving at mach 4 ground speed will have 553.4 kts ( 1025 km/h) EAS at 70000 feet

so Crotale, Roland , R-40 have higher EAS at their maximum altitude than Aim-120, Meteor have at 70K feet, and they all have much bigger wing, Sea Cat have lower EAS but it have much more massive wing, and it is very old missiles that unlikey be used again agile target, and it probably have terrible PK too
hornetfinn wrote:There is not much published about engagement altitudes, but Russian RVV-AE/SD is supposed to have similar altitude capabilities to R-33 with max engagement altitude of 25 km which translates to 82,000 ft. All I'm saying that MiG-31 does not have the altitude capabilities nor speed to stay safe from interception by modern medium-range missiles like AIM-120D, RVV-SD or Meteor. I doubt even SR-71 would be safe as Russians considered R-33 being able to shoot down SR-71.

according to Russian flights manual, AIM-120B, R-27ER can engage target fly at 30 km
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while R-27R is limited to maximum altitude of 20 km
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the USAF also have tested their AAM again target flying at 80K feet as it seem.
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the problem is they assumed target fly straight and level (aka missiles doesn't have to turn)


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by sergei » 12 Aug 2015, 13:57

hornetfinn wrote:
sergei wrote:The debate boiled down to a spherical horse in a vacuum.


That's how all of these X vs Y debates always are, what's your point?



"The problem with this scenario 10 F-35vs10 Mig-31/2 A-50 it is not possible.
F-35 never face Mig-31 because Mig-31 apply only against strategic targets and 10 F-35 not one of them.
If F-35 on guard some one only that time they have chances to see Mig-31 ,but not a very many opportunities they have something to do on this occasion."

"Mig-31 in air only if strategic targets already present and detected i.e AWACS/Tankers/Bombers/Cruise missiles."

"You will never be able to meet the 10 MiG-31 in one place "


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by eloise » 12 Aug 2015, 14:34

sergei wrote:"The problem with this scenario 10 F-35vs10 Mig-31/2 A-50 it is not possible.
F-35 never face Mig-31 because Mig-31 apply only against strategic targets and 10 F-35 not one of them.
If F-35 on guard some one only that time they have chances to see Mig-31 ,but not a very many opportunities they have something to do on this occasion."
"Mig-31 in air only if strategic targets already present and detected i.e AWACS/Tankers/Bombers/Cruise missiles."
"You will never be able to meet the 10 MiG-31 in one place "

you don't really have alot of pure bombers anymore , and iam pretty sure F-35 can cause more damage than a cruise missiles, and as we have explained for you before Stealth will also do the job of AWACS in future, especially in hostile area that normal AWACS cant get in without being shot down, and just because normal target of Mig-31 are big, slow tankers, AWACS, that doesn't mean pilot won't attack enemy's fighter if he have an opportunity
think about it this way: Tor-M1, Tungska are meant to protect the convoy from CAS aircraft such as A-10, su-25, AH-64.. etc. now, if an F-16 suddenly appear from no where and attack the convoy, do you think the driver of Tor-M1, Tungska will just leave them alone because they aren't including in his normal mission set?


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by geforcerfx » 12 Aug 2015, 18:47

sergei wrote:
hornetfinn wrote:
sergei wrote:The debate boiled down to a spherical horse in a vacuum.


That's how all of these X vs Y debates always are, what's your point?



"The problem with this scenario 10 F-35vs10 Mig-31/2 A-50 it is not possible.
F-35 never face Mig-31 because Mig-31 apply only against strategic targets and 10 F-35 not one of them.
If F-35 on guard some one only that time they have chances to see
"Mig-31 in air only if strategic targets already present and detected i.e AWACS/Tankers/Bombers/Cruise missiles."

"You will never be able to meet the 10 MiG-31 in one place "


I don't think you are understanding what the point of the thread is. We are pulling the mig-31 into a "unique" role to see if it's high speed and altitude capabilites give it a advatange over the aircraft that usually do the job. We get its not the normal mission so stop repeating it.


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by hornetfinn » 14 Aug 2015, 07:38

eloise wrote:in my opinion many older missiles have big wing because they need enough lift to compensate for their low speed ( either due to inefficient profile or the use of full boost motor)
Also even these missiles listed above still have more lift at their max altitude than Aim-120 at 70K ft
For example :
Roland maximum speed is mach 1.6 , maximum altitude is 5500 meters ( 18000 feet), at 18000 feet mach 1.6 ground speed is about 747 kts ( 1383 km/h) EAS

Crotale maximum speed is mach 2.3, maximum altitude is 5500 meters ( 18000 feet) , at 18000 feet mach 2.3 ground speed is about 1075 kts ( 1990 km/h) EAS

Sea Cat maximum speed is mach 0.8, maximum altitude is 5000 meters ( 16404 feet) , at 16000 feet mach 0.8 ground speed is about 389 kts ( 720 km/h) EAS

R-40 moving at mach 5 ground speed will have 691 kts ( 1281 km/h) EAS at 70000 feet

at 70K feet AIM-120 , Meteor moving at mach 4 ground speed will have 553.4 kts ( 1025 km/h) EAS at 70000 feet

so Crotale, Roland , R-40 have higher EAS at their maximum altitude than Aim-120, Meteor have at 70K feet, and they all have much bigger wing, Sea Cat have lower EAS but it have much more massive wing, and it is very old missiles that unlikey be used again agile target, and it probably have terrible PK too


Those SAMs are not going to be traveling at their max speed at their max altitude as their rockets would've burned out before that. Crotale motor burns for only 2.8 seconds reaching that Mach 2.3 and then the missile glides without forward thrust and decelerates. Roland has 1.7 second burning boost rocket (1600 kgf thrust) and sustainer rocket motor (200 kgf thrust) which burns for 13.2 seconds. I don't think it can climb vertically with such a low thrust sustainer rocket, so it would also have much lower speed than that at max altitude. Still, those missiles are still quite dangerous until their speed is reduced to near speed of sound.

We also don't know what the speed of AMRAAM (or Meteor) is at high altitude. Mach 4 (or over Mach 4) has been stated from the beginning with AIM-120A variant and later C-models and D-models have larger rocket motor which should translate to somewhat higher speed and higher achievable flight trajectories. Besides, Mach 4 at 70,000ft is pretty much equivalent to Mach 1.8 at 30,000 ft and air-to-air missiles have that kind of speed flying at about half their max range.

I'm not saying that MiG-31 going full speed and highest altitude isn't a difficult target for any air-to-air missile. It's however not SR-71 and even those were not safe against some air-to-air missiles or SAMs with similar or lower speeds and much inferior guidance systems. In your scenario however, I serioisly doubt MiG-31 could even theoretically have time and space to accelerate and climb to those altitudes. Without speed and altitude they'd be pretty easy targets to modern air-to-air missiles. I think of all Russian aircraft, Su-35 would be best for this task.


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by hornetfinn » 27 Aug 2015, 11:37

This topic made be ponder how well different design approaches would affect attacking large surveillance radar like AWACS or ground based search radars. Let's consider that the enemy will always be detected first be the surveillance radar in this scenario (that's one of the main jobs of having such radars in the first place).

Let's have a AWACS radar which can detect a fighter with 20 m^2 at 500 km away. Said fighter can attack the radar 100 km away. Let's say there is about 30 second reaction time from first detection to reaction. That would be a very good reaction time for surveillance radar system given radar system limitations and human operators needing time to process what's going on. I subtract this time from reaction time in the following.

If that 20 m^2 fighter is closing in at Mach 1, then there is over 22 minutes for the radar and defenses to react. If it's moving at Mach 2.5 there is still about 8 and half minutes of time for defenses to react.

If we drop the fighter RCS to 1 m^2 then the radar would detect the fighter at about 240 km away. The reaction time would be about slightly over 7 minutes at Mach 1. At Mach 1.5 speed it would be about a bit over 4.5 minutes and a bit over 2.5 minutes at Mach 2.5.

If we drop the RCS to 0.1 m^2, then the detection range would be about 135 km. The reaction time drops to less than 1.5 minutes at Mach 1 and to less than 50 seconds at Mach 1.5. At Mach 2.5 the reaction time would be only about 17 seconds. As a sidenote it can be calculated that 20 m^2 fighter would need to be travelling at over Mach 11 to have same reaction time as fighter with 0.1 m^2 RCS and Mach 1 speed. Alternatively it would need a missile with 420 km effective range against said radar to have 1.5 minute reaction time at Mach 2.5.

Dropping the RCS to 0.03 m^2 or less would mean that there would be no warning time, no matter how slow the fighter is moving as the radar could not detect it before it's engaged. This surveillance radar would need to be able to detect 20 m^2 target at over 1200 km range to have useful warning time against 0.01 m^2 fighter.

F-22 seems like a monster for engaging enemy AWACS and surveillance radars as it has stealth and great speed. However, F-35 seems extremely dangerous opponent due to very low RCS and decent speed. Combined with large numbers and EW it makes a very difficult opponent to counter. This calculation also shows why semi-stealthy fighter SH, EF Typhoon and Dassault Rafale have been designed.


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by sferrin » 27 Aug 2015, 13:11

Use one of these too. . .if we had any:

http://www.designation-systems.net/dusr ... -dash.html

(Stealthy AAM)
"There I was. . ."


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by eloise » 28 Aug 2015, 06:29

hornetfinn wrote:Those SAMs are not going to be traveling at their max speed at their max altitude as their rockets would've burned out before that. Crotale motor burns for only 2.8 seconds reaching that Mach 2.3 and then the missile glides without forward thrust and decelerates. Roland has 1.7 second burning boost rocket (1600 kgf thrust) and sustainer rocket motor (200 kgf thrust) which burns for 13.2 seconds. I don't think it can climb vertically with such a low thrust sustainer rocket, so it would also have much lower speed than that at max altitude. Still, those missiles are still quite dangerous until their speed is reduced to near speed of sound.

fair point, however, in my opinion these SAM still benefits from very big wing that compensated for their low EAS
anyways i think the performance of Meteor at 70K feet will be very similar to PAC-2 and PAC-1 at same altitude
they fly at around the same speed and have relatively similar ratio of fin size vs body size



hornetfinn wrote: We also don't know what the speed of AMRAAM (or Meteor) is at high altitude. Mach 4 (or over Mach 4) has been stated from the beginning with AIM-120A variant and later C-models and D-models have larger rocket motor which should translate to somewhat higher speed and higher achievable flight trajectorie

are you sure AIM-120D and C have bigger rocket motor compared to AIM-120A?, aren't they supposed to have same diameter?


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by hornetfinn » 28 Aug 2015, 09:19

eloise wrote:
hornetfinn wrote: We also don't know what the speed of AMRAAM (or Meteor) is at high altitude. Mach 4 (or over Mach 4) has been stated from the beginning with AIM-120A variant and later C-models and D-models have larger rocket motor which should translate to somewhat higher speed and higher achievable flight trajectorie

are you sure AIM-120D and C have bigger rocket motor compared to AIM-120A?, aren't they supposed to have same diameter?


Yes I'm sure. The diameter is the same but the rocket motor is lengthened (longer burn time).

http://www.dote.osd.mil/pub/reports/FY2000/airforce/00amraam.html

The AIM-120C was developed with clipped missile's wings and fins to reduce its box size from 17.4 to 12.5 inches. This allowed for increased internal carriage loadout in the F-22. Block change lethality improvements are being incorporated into the missile from Lot 8 and beyond, culminating in a new warhead and lengthened rocket motor in Lot 12.


Range improvements have also been mentioned with AIM 120C-5, AIM 120C-7 and AIM-120D each. I don't know if this has involved improvements to rocket motor.


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by sergei » 28 Aug 2015, 13:46

hornetfinn wrote:
eloise wrote:
hornetfinn wrote: We also don't know what the speed of AMRAAM (or Meteor) is at high altitude. Mach 4 (or over Mach 4) has been stated from the beginning with AIM-120A variant and later C-models and D-models have larger rocket motor which should translate to somewhat higher speed and higher achievable flight trajectorie

are you sure AIM-120D and C have bigger rocket motor compared to AIM-120A?, aren't they supposed to have same diameter?


Yes I'm sure. The diameter is the same but the rocket motor is lengthened (longer burn time).

http://www.dote.osd.mil/pub/reports/FY2000/airforce/00amraam.html

The AIM-120C was developed with clipped missile's wings and fins to reduce its box size from 17.4 to 12.5 inches. This allowed for increased internal carriage loadout in the F-22. Block change lethality improvements are being incorporated into the missile from Lot 8 and beyond, culminating in a new warhead and lengthened rocket motor in Lot 12.


Range improvements have also been mentioned with AIM 120C-5, AIM 120C-7 and AIM-120D each. I don't know if this has involved improvements to rocket motor.

120C-5/7

AIM-120C-5 is a AIM-120C-4 modified with a shorter control section with electronics smaller dimensions,
this allowed to increase the length of the fuel charge and increase the range.
Warhead C4 22.7 kg-Warhead C5 18kg
Also on missiles was applied new software.
AIM-120C-7 same as AIM-120C-5vsAIM-120C-4.
I.e "rocket motor" was not improved.


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by eloise » 21 Sep 2015, 00:05

So i recently found this , some onety to estimated missiles turn performance , what do you guy think ? accurate or not :?
Image

http://www.aviation.org.uk/docs/flightt ... 108/c6.pdf
http://forum.keypublishing.com/showthre ... -thread-(2)&p=2030179#post2030179


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by hythelday » 24 Apr 2019, 07:12

MiG-31 allegedly shot down another MiG-31 with an R-33 in 2017:

https://translate.googleusercontent.com ... YS7JrFeLgA

"Zaslon-AM" IFF blamed for the mistake.


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