AWG-9 and APG-71

Cold war, Korea, Vietnam, and Desert Storm - up to and including for example the A-10, F-15, Mirage 200, MiG-29, and F-18.
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eloise

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Unread post02 Feb 2020, 21:25

Does anyone have any sources about the range of these F-14D radar?
I got this
D83AE05F-FC71-4ED0-BA6A-408896F63A3A.png

https://www.forecastinternational.com/a ... ARC_ID=113
But I feel like that is too short.
I also found
In the 1960s, the AN/AWG-9 was at the forefront of cutting edge radar design. With the new HPRF transmission/reception and automatic tracking being incorporated into its design. However, unlike other radars of this new generation, the AWG-9 retained its 'man in the loop' design of past 'pulse radars'. The RIO would still be able to manually pick up faint targets (or targets masked by clutter) that the automatic system wouldn't. Even today, automatic trackers need the target to be ~12dB (16 times) stronger than the noise in order to track. A skilled operator could do the same with a target only 3dB stronger than the background noise. https://i.imgur.com/2zf64Tc.png?1
Thus, where these new processes failed, a human could step in and in many cases out perform the automatic processes of the receiver.
Additionally, the AWG-9 would also retain old school 'pulse radar' processes (LPRF waveform) adding further versatility to the sensor. (the LPRF was retained for 'all aspect' detection and ACM modes, but proved inferior to MPRF waveforms used by later radars)
As if it wasn't enough, the AN/AWG-9 had an extremely powerful transmitter and very large antenna, giving it a narrow beamwidth. This combination made it the most powerful fighter radar (raw effective radiated power) up until the APG-77.
However, the radar was designed primarily with 1960's equipment and sported an analog receiver. Leading to poor look down performance amid terrain, especially in automatic modes.

All that being said, she represents the best analog airborne radar ever made, but her performance is highly predicated on the skill of her operator.

One of the devs mentioned a detection range of about 110nm (in PD search; 90nm in RWS) against a fighter sized target. Giving it greater range than the F-15 and F-18. However, the AWG-9 lacks Medium PRF, giving it a distinct disadvantage against low Doppler (flanking) targets.

https://www.reddit.com/r/hoggit/comment ... nt/e7e2p6j
But it is only a Reddit comment, anyone have better information?
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garrya

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Unread post03 Feb 2020, 07:29

From "Grumman F-14 Tom Cat in combat" by Frederic LERT
AWG-9.PNG

APG-71.PNG


From "uncovering the Grumman F-14 A/B/C/D Tom Cat" by Danny Coremans
AWG-9 2.PNG

APG-71 2.PNG


take it with a grain of salt

IMHO, the most accurate is from "Grumman F-14 Tomcat leading fleet fighter" book by Dennis R. Jenkins because unlike others, he is a consulting engineer in Cape Canaveral, Florida, working on various aerospace projects including 20 years on the Space Shuttle and several on the X-33 program.
AWG-9 (3).PNG

APG-71.PNG
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garrya

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Unread post06 Feb 2020, 08:43

From "Mikoyan Mig-31" by Yefim Gordon
mig-31.PNG

mig-31 2.PNG

mig-31 3.PNG
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hornetfinn

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Unread post12 Feb 2020, 12:25

I think comparison between N007 Zaslon radar and AWG-9/APG-71 are very interesting. It seems obvious that AWG-9/APG-71 had more sensitive receiver, more efficient antenna and better processing capabilties. It seems to have longer detection and tracking range despite having quite a bit smaller antenna and similar transmitters. It could also track more targets simultaneously. Of course Zaslon had the advantage of being able to steer beams almost instantaneously anywherre. So it could track targets with much wider separation.

I think both radars were best possible solutions at the time. Phased array antenna would've been too heavy even for F-14 at the time. It also has some performance penalties as phase shifting in the antenna introduces additional losses. Since having maximum detection range possible was crucial for their mission while having minimum weight penalty for carrier aircraft, having planar MSA antenna was the best way of doing things.

For MiG-31 the passive phased array antenna was the only possible choise given requirement to engage multiple low flying targets simultaneously. Active radar guided missile was probably not possible at the time for missiles small enough to be carried by fighter aircraft. Passive phased array system allowed tracking decent number of widely separated low flying targets and engage them simultaneously using semi-active guided missiles. Some loss of detection range was not big deal as it had good range still.
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mixelflick

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Unread post12 Feb 2020, 14:42

Both the AWG-9 and AN/APG-71 were incredible radars, especially for their time. Same could be said of the Foxhound's radar. And while neither entered into combat with each other, it would have been an interesting fight. We know Iranian F-14's downed several Foxbats, or at the very least caused them to abort their mission. One Foxbat being chased by an F-14 took a wrong turn, ran out of fuel and crashed. That too, was counted as a kill.

Could the F-14 catch up to a Foxhound? Tough call. It caught Foxbats, but in all of my reading the highest speed these Foxbats were recorded at were mach 2.3 - 2.4ish. I saw no mach 2.8 figures, which supposedly was its red - line. The Mig-31's max speed is listed at mach 2.8, although I'd say with weapons that was doubtful. One interesting anecdote was that an Iranian F-14 was said to reach mach 2.3 during one chase, the fastest in combat I've ever heard of one flying. It took a Phoenix shot from that range (actually, I think 2 of them).

The Foxbat defeated the first missile but then feeling safe, decelerated. That proved to be his undoing, as the 2nd Phoenix quickly found its mark. I'm sure American intelligence found all of this very interesting, assuming of course they were privy to it. Both phenomenal aircraft/radars, both still fly today.

Remarkable, when you think about how long ago they were both created...
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hornetfinn

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Unread post12 Feb 2020, 15:44

F-14 vs. MiG-31 would've been an interesting fight for sure. Of course neither was really designed for that fight, but both were likely still very capable BVR machines. F-14 was clearly superior in maneuverability while MiG-31 had superior speed and high altitude capabilties. F-14 also had more capable close-in weapons in the form of AIM-9 as MiG-31 only had the small and short ranged R-60. AIM-7 was also likely more effective weapon against fighters than the huge R-40. So if R-33s and Phoenix missiles missed, then F-14 was going to win a fight but MiG-31 would likely just run away if it went to that.

But both were very capable in their main roles of fleet defence and long range interception of bombers and cruise missiles. It would've been daunting for bomber crews to go against either one.
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mixelflick

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Unread post13 Feb 2020, 16:38

I agree.

Frankly, I'm perplexed as to why Iran or another nation hasn't purchased Mig-31's. It's absurdly capable at least insofar as defending vast swaths or airspace, Iran's nuclear facilities etc... Up until the F-35 acquisition by Israel, I'd go so far as to say it would be a very destabilizing influence in the Middle East. The Mig-31 is given a lot of respect and for good reason: It's one of the few interceptors that can engage/re-engage at will due to its long range and blistering speed.

I have no doubt Israeli F-15's would have probably carried the day, but the Mig-31 would present an entirely new and dangerous calculus in any strike on Iranian reactors. I understand sanctions are likely the reason they haven't been acquired, but if memory serves they'll be lifted soon.

When they are, I guess it'll be a toss up between the SU-30SM, SU-35 and SU-57. I'm not sure if the Mig-31 production line is closed, but it might be possible Russia sells them some of their earlier models. Intriguing possibilities ahead...
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Tiger05

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Unread post14 Feb 2020, 00:00

While the MiG-31's maximum speed is officially Mach 2.8, in the real world they are prohibited from reaching that speed. This is what i remember from an article on the aircraft that was published a few years ago in Combat Aircraft magazine. I dont recall precisely what was the speed not to exceed but it was closer to Mach 2 than to Mach 3...
Last edited by Tiger05 on 14 Feb 2020, 23:08, edited 1 time in total.
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marsavian

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Unread post14 Feb 2020, 00:49

Mig-31 steady state supersonic cruise speed is Mach 2.35. Mach 2.83 is available as a maximum. It's only at Mach 3 the engines get damaged. However there are other problems to Mach 2+ cruising for the Mig-31 as well as the poor 5g turning limit for maneuverability.

https://www.google.com/amp/s/theaviatio ... -plane/amp

Five minutes after take-off, the MiG was already at an altitude of 16000m (52,493ft). The afterburners would still be lit and the crew experiencing significant g. In addition, the MiG-31 had a disconcerting idiosyncrasy – at high supersonic speeds (above Mach 2.35), the control stick moved all the way forward, pushing up against the instrument panel. The pilot had to extend his arm fully, which was very uncomfortable and quickly caused fatigue. However, the MiG-31 was significantly more benign in its flight characteristics at supersonic speeds than the MiG-25. The great weight of the MiG-31’s on-board equipment and systems had an effect on its performance compared to the ‘Foxbat’, but its instrumentation was significantly greater and a generation more modern.

The SR-71 was intercepted using only a thermal channel (infrared, IR). The massive IR emissions of its engines permitted it to be detected at a distance of 100-120km (62-75 miles). The MiG-31’s thermal detection system was called OMB (or optical multifunctional apparatus) and was mounted in the lower nose of the aircraft. The device was lowered and turned on by the WSO. The MiG’s radar was not turned on. On combat alert the radar was set on a combat frequency, and in order not to expose this frequency to a ‘probable enemy’, the radar was not turned on. A passive system (the thermal apparatus) was adequate for a reliable intercept.


“After the take-off order from the command post we lit the afterburners and took off. Our take-off speed was approximately 360km/h [224mph]. Not coming off afterburners, we went for altitude with a 60° right bank and turned to a course of 100°. We attained 8,000m [26,247ft] and reached the horizontal area (for acceleration) in which we passed through the sound barrier. Here vectoring station `Gremikha’ had already assumed responsibility for vectoring us. Our indicated speed at this time was 1,190km/h [739mph]. We went for altitude again, up to 16,000m [52,493ft]. At 16,000m we were flying at Mach 2.3 and made a left turn to a combat course of 360°. The WSO lowered and turned on the OMB and within five seconds had captured the target. A feminine voice in the earphones announced, Attack’, and a symbol was illuminated on the SEI. The SR-71 was proceeding on the ‘return loop’, from east to west, so we began the intercept immediately.

“As usual, we executed an ‘aiming run’ from 16,000m, gaining altitude to 18,900m [62,008ft]. After closing to 60km [37 miles] I spotted the contrail of the SR-71 on an intersecting course. I reported the heading to my WSO over the SPU [samoletnoye peregovornoye ustroystvo, intercom], ‘I have visual!’ A contrail at 22,000-23,000m [69,000-72,000ft] is very rare, but on this day the weather was excellent and the air was transparent, and the contrail was clearly visible. I passed under the spyplane: it was 3,000-4,000m [8,843-13,123ft] above us, and even managed to make out its black silhouette. The SR-71 was flying over the ocean ever so carefully on a track 60km [37 miles] out from, and parallel to, the coast. I reported ‘we’re breaking of to the command post and came off afterburners. We had been airborne for 15 minutes 40 seconds.

“The Blackbird was flying its normal route, over neutral waters, and it made no sense to follow it. Therefore the vectoring station gave the command to turn onto a course for our airfield. We dropped down to 15,000m [49,212ft], transitioned to horizontal flight, and engaged a stopwatch. This was the so-called ‘area for canopy cooling’. During flight at speeds in excess of Mach 2, the skin, including the canopy, heated up to 800°C. Therefore it was necessary to cool it. Failure to do so might result in cracking or catastrophic failure during subsequent altitude reduction. Our speed remained in the order of Mach 1.6.

“After 30 seconds we once again began to lose altitude. We went subsonic at the normal 12,000m [39,370ft].
Dropping down to 8,000m [26,247ft], we tracked toward our airfield. After the last vector was issued the command centre handed us off to our regiment command post, which directed me to a checkpoint at an altitude of 4,100m [13,451ft]. At 32km [20 miles] out from the airfield I lowered the gear and began to descend. We conducted a straight-in landing at a speed of 310km/h [193mph] . The entire flight had lasted 50 minutes.


Kazakhstan inherited about 30 from the Soviet Union with about 20 still in service.

https://www.globalsecurity.org/military ... g-31bm.htm
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hornetfinn

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Unread post14 Feb 2020, 10:15

mixelflick wrote:I agree.

Frankly, I'm perplexed as to why Iran or another nation hasn't purchased Mig-31's. It's absurdly capable at least insofar as defending vast swaths or airspace, Iran's nuclear facilities etc... Up until the F-35 acquisition by Israel, I'd go so far as to say it would be a very destabilizing influence in the Middle East. The Mig-31 is given a lot of respect and for good reason: It's one of the few interceptors that can engage/re-engage at will due to its long range and blistering speed.

I have no doubt Israeli F-15's would have probably carried the day, but the Mig-31 would present an entirely new and dangerous calculus in any strike on Iranian reactors. I understand sanctions are likely the reason they haven't been acquired, but if memory serves they'll be lifted soon.

When they are, I guess it'll be a toss up between the SU-30SM, SU-35 and SU-57. I'm not sure if the Mig-31 production line is closed, but it might be possible Russia sells them some of their earlier models. Intriguing possibilities ahead...


MiG-31 definitely looks like very capable long range interceptor which would increase for example Iran's capabilties. I think the reason they have not been exported much is because Russia itself needs them badly. AFAIK, the production of MiG-31 ended about 25 years ago and they probably can't make new ones now without major effort. I think Russia is much more interested in selling new Su-30s and -35s which would be major improvements for Iranian Air Force also. But it seems like they don't have that much money to acquire new fighter aircraft. They have only been able to buy a small amount of new or slightly used aircraft and most of their inventory is either from 1970s acquisitions from USA or "donations" from Iraq during Desert Storm. They'd badly need replacements but it seems they can't afford them and/or sanctions make it impossible to buy modern equipment.

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