Nothing is as beautiful in service with the VKS at same time still reflects the overwhelming might of the Soviet Union that came before it.
Anyway aim-120. Sure I will respond tomorrow. I wanna play WT.
The R-77 range envelopes posted here an in your R-77 thread seem to indicate a maximum head-on air-to-air launch range of about 15 km at sea level. So a maximum range of 12 km when fired from stationary doesn’t seem too unreasonable.
On a sidenote 15 km head on range at sea level is worse than the AIM-7F and even Skyflash SuperTEMP. In fact it’s not that much better than the AIM-7E. Why does the R-77 perform so bad at sea level?
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I would assume at low alt where air is dense and there is not enough airflow passing through the grate and as result it is almost acting like a paddle and as if it is a flat surface.
where do you get such nonsense from?
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@BBCRF This graph in the main post of @MiG_23M 's R-77 thread:
https://cdn.discordapp.com/attachments/398367636213334018/1143042513633022052/image.png
That looks like 15 km range at sea level to me. Someone also posted another diagram earlier in this thread showing a similar range at sea level.
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He uses this diagram as “proof” of the missiles upper range limits (instead of the stated 80km max from both KTRV and rosboronexport) but disagrees with its lower range limits and questions its veracity.
He’s done this multiple times, and this dishonesty is one of the main reasons why I ended up blocking him so as to no longer waste my time interacting with his comments or arguing with someone so clearly biased.
He also asserts some downright ludicrous stuff such as the missile acheiving M4.0 over launch speed, which would be a dV of roughly 1372m/s, and would still be a dV of roughly 1181 m/s at 10000m, which would mean its outperforming both the R-27ER (with its considerable larger motor) and the AIM-7M (with its near identical proportions) rather substantially. It would also mean that a M1.0+ launch would lead to this missile being hypersonic, and even the russians dont claim its a hypersonic missile…
Even M3.0 over launch speed would put it at a dV of around 1029m/s, slightly better than the 7M, slightly worse than the 27ER, which is a lot more realistic. Granted im not a fan of stating it “achieves X mach over launch speed” seeing as its aerodynamics are atypical due to the grid fins, due to high transonic drag, and lower high supersonic drag, so its actual achieve dV is much more related to its launch speed than missiles with planar fins which increase drag with increasing speed in a more conventional fashion.
Theres no real reason to believe the missile is particularly different to the 7M kinematically. It likely has an advantage at the upper end of its range envelope when launched at supersonic speeds due to the grid fins, but would suffer greatly at subsonic/transonic launches, which explains why it only attains a range of 12km when surface launched compared to the RIM-7M’s 26km.
He really just acts like Russians are the only nation on Earth that know how to design missiles and that the R-77 and R-27ER are god/the soviets/whatever you believe in’s gift to this ungrateful world.
Kinematics of russian missiles are perfect and any and all claims that they struggle in X scenario is a “seeker limitation” or whatever new excuse is cooked up to explain away their underperformance obviously 🙄
We’re kinda getting off topic tho, seeing as this is an AIM-120 thread…
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this graph is complete nonsense, no one will show you a real graph. I can draw that too
V=V0+dV/dt
R-27ER,ET,R-40RD,TD,R-33,S,R-37,37M all hypersonic missile.Max speed R-27ER 1800 m/s
all air-to-air missiles can reach hypersonic speed. Another thing is that their speed lasts only a few seconds
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The graph isn’t very accurate as we’ve come to know. Plugging in the numbers for the booster and considering missile drag values 1.5-2 or even 3x what they would be expected yielded ranges close to 80-100km when testing in-game using custom missile files at altitude (even when launched from 0.9-1.1 mach against a co-speed and co-alt target). I could test at lower altitudes, but my expectation is that ground launched will yield 20-30km maximum range thanks to the lack of lofting and limited time at high supersonic speeds to improve range from grid-fin design.
Mythic doesn’t understand how deltaV works it seems. Directly comparing deltaV between missiles without considering drag, size, burn time, etc and even then comparing it to the AIM-7M for some very odd reason.
So you have some data about AIM-120 supersonic launches?? Can I see these??
21st August, 2002 Lt. Col. Eddie Cabrera is at the controls of Raptor 03 for the first supersonic separation test of an AIM-120 AMRAAM at Mach 1.19.
https://cdn.discordapp.com/attachments/955829235493273680/1156273508184228031/F22M_2002_06_Supersonic_AIM120_1267828237_5437.png?ex=65145f1e&is=65130d9e&hm=dc24281fa66b64b7ee1e8483e2d1e7464b8db70b8157c738411a2d4ac5092dba&
These tests were important to determine safety of supersonic missile separation after exiting the weapons bay of the expensive fighter. It was perfect.
Supersonic missile launches are actually desired.
https://cdn.discordapp.com/attachments/955829235493273680/1156274378582016031/image.png?ex=65145fee&is=65130e6e&hm=9f9a26fcb0ab323368a9a3b97f1d78806c1d34cb7f48c535134a6469656455d8&
There is also the fact that other missiles designed around the time period of the AMRAAM requiring supersonic inlet air (ramjets) exist. They would not be so focused on such technology, or there would be existing reports determining it was difficult / had the challenge of overcoming supersonic launches if there was a problem. There is no such mention of this being an issue, because it’s not one.
So you try say to me that first ever supersonic deploy AIM-120 was 11 years after introduce it in duty??
Sorry but it’s like not consistent like 20 post before you claim that is no proof that maiority launches are subsonic… And now you give article that after 11 years of active duty US make first attempt to supersonic test??
You are serious!? Or I’m just don’t understand some thing ?
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That was clearly not the first, what’s shown is an AIM-120C. The only time they’ve needed to do proper supersonic testing for missile launches is for separation testing on AMRAAM. Likewise, with Meteor there seems to be no concern for aerodynamic heating. I see no reason they’d be less reliable when launched from sub vs supersonic.
Further, in most materials I’ve read they seem to desire supersonic launch speeds. That is the norm.
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It’s interesting, I was considering other missiles with public data such as MICA are stated 20km range from surface launch and 60-80km range in high alt air launched scenario. If the MICA can do 20km, the RIM-7M can do 26km, why does the RIM-7M have ~100km kinematic performance and MICA only 60-80?
Further, if the R-77 is stated as an 80-100km range missile, why does it have (allegedly) less range from surface launch? These things do not add up and as such, further testing was required. From this testing, we can state with a high degree of certainty that the R-77’s 12km ground launched range is the distance it intercepted an oncoming target, or was a seeker limitation. It would have more kinematic range otherwise from ground launch.
Wouldn’t a surface launched R77 suffer the worst from transonic drag factors because of the increased drag and air density?
I assume it would be launched at a cruise speed so like mach .8-.9
The transonic speed will last 0.1-0.2s
It has equal performance to conventional missiles and suffers only from a region between 0.8 and 1.3 mach. That does not mean it suffers the entire time between 0.8 to 1.3, but the envelope in which it does is somewhere within that region.
Anyhow, the missiles’ acceleration is such that it would go beyond 1.3 mach within ~1-1.5s from launch… and as @BBCRF stated the transonic region lasts but a moment in that time. It would have a noticeable impact if it weren’t also for the fact that the missile has IMPROVED drag performance at high supersonic speed. This is advantageous as once the missile is going fast, it stays fast longer. This easily offsets any wave drag issues in the transonic region.
No launch parameters mentioned and this has been shared before… not really useful and was shared previously.
How tf did you get to 0.1-0.2 second lmao.
If the (frankly absurd) claim that the R-77 reaches speeds of M4.0 (dV = 1372m/s roughly) over launch are true, with an estimated 6-8 second burn time, that gives us an average acceleration between 0.5-0.67 Mach per second.
Ground launched, this would equate to something between 1.94-2.6 sec before it reached M1.3, of which it would spend roughly 0.75-1sec in the transonic region
If we use a more reasonable M3.0 over launch speed (roughly between the 7M and R-27ER), that gives us an average acceleration of 0.375-0.5 Mach/s.
Ground launched, that would equate to 2.6-3.47 sec to reach M1.3, of which it would spend roughly 1-1.33 sec in the transonic region.
In the most favorable of analysis (M4.0 over launch speed), this equates to spending almost 32.3% of its total motor burn time either subsonic or in the high drag transonic regime, of which 12.5% of the burn time is spent specifically in the high drag transonic region where the grid fins act as airbrakes.
In the more realistic of analysis (M3.0 over launch speed), this is roughly 43.3% of the motor burn time before it reaches M1.3, of which 12.5-16.6% is in the transonic region.
Neither the optimistic M4.0 over launch, nor the more realistic M3.0 over launch lead to your assertion of the transonic speed lasting 0.1-0.2 sec. We can use basic math to determine your claim is just outright ludicrous.
Beyond that fact, the general assertion that “X missile reaches Y speed over launch speed” is absurd. Max missile launch speeds, and speed gained are determined by environmental factors such as air density, missile drag profile, motor thrust curves, etc… and is is the case with the thrust curve you provided for the R-27ER, there can be upper limits to achieved speeds considering these factors.
This can be seen in the R-27ER chart you previously brought up, with the Max achievable speeds according to the chart being 1800m/s while dV’s per altitude are;
5km: 900m/s = M2.81 over launch speed (M4.37 peak speed from a M1.56 launch)
10km: 1000m/s = M3.34 over launch speed (M5.34 peak speed from a M2 launch)
15km+: 1200m/s = M4.07 over launch speed (M6.1 peak speed from a M2.03 launch)
So calculations like the ones I just did or the ones some others partake in with theorizing/asserting the R-77’s capabilities are little more than napkin math anyways, PARTICULARLY in the case of the R-77 and its unusual drag profile.
Considering the drag profile of the R-77 is SPECIFICALLY optimized for high speed launches, its REALLY not surprising that it would suffer in subsonic/transonic, or even stationary launches quite substantially. The 12km surface launch number really doesn’t seem all that wild considering this fact.
BEYOND all that, this is an AIM-120 thread, and we’re really getting off topic with all this R-77 talk and the videos at this point.
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Accelerating at 0.5 mach per second it will pass through the brief envelope of wave drag (likely around 0.9 to 1.2 mach) in ~0.6-1s or less draining minimal energy and recover it easily in comparison to conventional fin missiles at the top end where it has drastically improved aerodynamic drag at high supersonic.
As I stated…
Comparing it against other missiles using deltaV is ridiculous imo.
Python 4 for example in-game has a calculated deltaV near 1100 m/s… lol that’s similar to R-27ET.
Since a lot of the deltaV for some of those missiles is in the sustainer phase (such as R-27E series), and the R-77 relies on boost-only… it has a higher chance of overcoming drag to reach mach 4 (especially with it’s design).
I’m not seeing how this math works out, and we’re not 100% certain it’s mach 4-4.5 over launch or if that’s the maximum speed of the missile… even then it could be wildly inaccurate as we only recently found out the AIM-54A is a mach 6 capable missile when launched from 2.4-2.5 mach.
Yes, missile top speed is determined by a lot of other factors than deltaV which is what you’re conveniently ignoring when making these then equally absurd comparisons to other missiles.
Yes, and so you see how ridiculous it is to make such comparisons?
It’s actually quite useful if you’re not doing it in such a biased manner ignoring all other factors, sources, information on the grid fins, etc like you have been. You won’t even reply to me and choose to ignore what I’m saying in an attempt to avoid the truth as far as I am concerned.
It’s a good point of comparison to the AIM-120 seeing as it’s the analogue for the AIM-120C-5.
Anyhow, I can’t remember if I stated mach 4 over launch speed or not… if I did it was erroneous / wrong. Top speed of mach 4-4.5 similar to AIM-120 but with better retention of high supersonic speeds would be more accurate. In fact, top speed of mach 5+ is still easily possible for R-77 if launched from 2.5 mach.
My lowest estimate of deltaV is 942 m/s currently. If you want to use this as the be-all-end-all consideration for top speed, that is.