Will the F-35 replace the F-15 in the USAF?

[OPSSG]

Pricing is a little complex and subject to much discussion / disagreement. Thread with care, as you are not using the usual language.

Sorry, I don't follow your reasoning, but any helpful hints are welcome by me.

There are many ways of reporting unit costs of aircraft, such as, flyaway cost, recurring flyaway cost, non-recurring flyaway cost, which may include alternate mission equipment but not weapons or spares and so on. This essay explains what each of these terms mean, and may be of help to you. If you are not confused by the terms in the essay, you may want to read this too, which attempts to confuse readers about the real cost of modern fighter aircraft.

 

[Zaphael]

Its too early to rule out the F-35's capability in the air to air role. The F-15C/Ds are getting old and may go soon, and it seems like the F-35s the only jet in line to fill in those functions.

A couple of pieces of information are missing that prevents a comprehensive understanding of what the new 6 air superiority wings are going to be like. One, I do not know the type of capabilities the USAF intends include in the composition of the wing. Two, I don't know what would constitute the 72 "primary mission aircraft."

To answer the question of whether the F-35 can replace the F-15, I think it would be good to understand exactly what is being replaced. IMO, the F-15s stood out from the rest of its 4th gen series of fighters in its ability to detect targets with its radar at a greater distance. Its eyes, together with its legs; two power PW engines, allowed it to employ BVR missiles like the AIM-120s more effectively. Without getting into too much boring details, being able to detect a target first, then climbing up to a higher altitude in excess of Mach 1.0 airspeeds, enable the AIM-120s to reach out further and kill their targets. Those who have messed around with Sims like LOMAC would be aware that the Eagle can track and support two AIM-120 shots on two separate targets. Impressive stuff.

Close in, the F-15 can also hold its own in a WVR engagement during its time. I am excluding the JHMCS and AIM-9X when assessing this as I'm really focusing on its agility. Unlike the MiG-25 Foxbat, the F-15 was a capable dogfighter at high and medium altitudes. Until the Su-27 came along, there really weren't really many fighters that did both the BVR and WVR jobs as well as the F-15.

Can the F-35 step into these shoes? I'm not surprised if it can. Firstly, capabilities are evolving that allow radars to detect and track targets as well as the APG-63 series found on the Eagle. In fact, they'll work faster and better. Secondly, the F-35 will have a very powerful engine that produces up to 43,000lb in full afterburner. From the numbers off wikipedia, with just a full load of fuel and maybe four AIM-120s, the F-35 would probably still retain a good thrust to weight ratio in excess of 1:1. In that, its internal weapons storage and cleaner aircraft design would probably allow it to accelerate better and more efficiently than the Eagles.

Throw in the lower radar cross section, the aircraft attacking the F-35 might find itself not only being a little lost at trying to find the F-35, but at an altitude and energy disadvantage for a BVR joust. The same can be said for the F-22 about the F-35 as well. They get up and get going better.

In the WVR environment, I think my inference of the US air combat doctrine tells me that its something to be avoided if possible. And the F-35s's EO-DASS systems reflect that kind of attitude towards dogfighting. The F-35 will not only separate on the merge, but even lob an over-the shoulder missile shot to discourage the offending aircraft from turning. Again, this information can be found on youtube.

Of course, all this rambling from me is useless without factoring new developments like the Pak-Fa. I'm not going to discount it yet, but considering how far ahead the F-22 and F-35 program is ahead of the Pak-Fa, and that there is no other 5th generation platform in service anywhere else, the F-35 seems capable enough to stand in for the Eagles until the next QDR figures its a good idea to factor in the proliferation of 5th gen combat aircraft.

As of now, the main strategic priorities of the U.S. are found in the Middle East, and North East Asia. None of the potential adversaries in these regions, namely Iran and North Korea are fielding close to as many 4th generation fighters as the US regional commands are. China is not a real threat yet despite less than warm relations. It has many common security and economic imperatives with the U.S and would not want to confront the U.S. militarily. Russia's main focus will most likely to be centered on Europe. Its conventional military capabilities are still not threatening to Europe yet, and it seems that the Europeans are in good enough shape to take care of their own security already, albeit under American coordination through NATO. Still, they've got the numbers and the technology.

Hence, I don't see any reason why the F-35 cannot replace the F-15 with its Air to Air capabilities. However, I am not sure if it will be at the 1:6 ratio. A high intensity air war, which is largely unlikely for the near term, would involve Defensive Counter Air operations and CAPs along a fairly large front. The F-35s may not be able to make up the numbers required to maintain that kind of coverage. This is why the QDR also emphasizes on building up strategic security partnership with friends and allies of the United States. In short, they've got to pull their own weight as well.

 

[the_big_m_in_ok]

With respect to Reply #61,
Boeing is touting the newest version of the F-15 (Silent Eagle), whose exact particulars and specifications are still sketchy, by my experience, since the plane isn't scheduled to enter production until, say, 2011-2012. That's what I remember.

Unclassified 'Web sources:
F-15SE Silent Eagle - Wikipedia, the free encyclopedia

PICTURES: Boeing unveils upgraded F-15 Silent Eagle with fifth-generation features-17/03/2009-Washington DC-Flight International

Now, my point is: Boeing is obviously proud of their plane and point out that their offering is supposedly less costly than the F-35 or F-22.
Whether or not that's true, remains to be seen in a---hopefully---level-playing-field, head to head competition. Also, the flyaway price for the F-15SE may not be predictable as any kind of bargain or can remain low enough to be competitive in time---assuming buyers will come forward with orders in the future.

 

[Zaphael]

With respect to Reply #61,
Boeing is touting the newest version of the F-15 (Silent Eagle), whose exact particulars and specifications are still sketchy, by my experience, since the plane isn't scheduled to enter production until, say, 2011-2012. That's what I remember.

Unclassified 'Web sources:
F-15SE Silent Eagle - Wikipedia, the free encyclopedia

PICTURES: Boeing unveils upgraded F-15 Silent Eagle with fifth-generation features-17/03/2009-Washington DC-Flight International

Now, my point is: Boeing is obviously proud of their plane and point out that their offering is supposedly less costly than the F-35 or F-22.
Whether or not that's true, remains to be seen in a---hopefully---level-playing-field, head to head competition. Also, the flyaway price for the F-15SE may not be predictable as any kind of bargain or can remain low enough to be competitive in time---assuming buyers will come forward with orders in the future.

And I think Boeing's point was that they are targeting the SE at a limited spectrum of customers who would use the SE in a Defensive Counter Air type of role. Naturally the SE should also cost less than the new 5th gen aircraft like the F-22 and F-35. The F-15SE is essentially a 4.5gen aircraft with some new 5th RCS reduction features.

Like what the website says, it has little effect on ground based radar systems and is meant to reduce the head-on returns from the jet. A good feature that provides a distinct advantage in a BVR situation where missiles are primarily radar guided.

The F-15SE is still in many ways nowhere close to leveling the playing field with the F-22 or F-35. It will be interesting to see which countries decide to pick up the SE though.

 

[the_big_m_in_ok]

...And I think Boeing's point was that they are targeting the SE at a limited spectrum of customers who would use the SE in a Defensive Counter Air type of role. ...
The F-15SE is still in many ways nowhere close to leveling the playing field with the F-22 or F-35. It will be interesting to see which countries decide to pick up the SE though.

Well, Boeing would certainly like to sell as many as possible. As you said, or intended, foreign countries would need to decide of the F-15SE is worth buying.

Naturally the SE should also cost less than the new 5th gen aircraft like the F-22 and F-35. The F-15SE is essentially a 4.5gen aircraft with some new 5th RCS reduction features.
...
Like what the website says, it has little effect on ground based radar systems and is meant to reduce the head-on returns from the jet. A good feature that provides a distinct advantage in a BVR situation where missiles are primarily radar guided.

Which reminds my that I read in a journal awhile ago, and I'll now look up another informal reference on the 'Web:

Air-to-air missile - Wikipedia, the free encyclopedia
Introduction to Air-to-Air Missiles (AAM) | Air to Air Missiles at DefenseTalk

Reducing the head-on radar signature seems to be something rewarding to achieve, to put it mildly. The newest generation AAMs or SAMs should be more capable than previous designs of engaging in an a closing, approaching target shot with an enemy aircraft bearing down on the defender. A single shot may be all one gets.

The newest radar for the F-15s, such as...

AN/APG-70 Radar System

...had better be able to perform to advertised specifications if customers are going to line up for orders. That also goes for the F-22 and F-35.

Fortunately, R&D on systems should proceed as long as money is spent to bring ever-better systems to the field.

 

[Zaphael]

Well, Boeing would certainly like to sell as many as possible. As you said, or intended, foreign countries would need to decide of the F-15SE is worth buying.

Which reminds my that I read in a journal awhile ago, and I'll now look up another informal reference on the 'Web:

Air-to-air missile - Wikipedia, the free encyclopedia
Introduction to Air-to-Air Missiles (AAM) | Air to Air Missiles at DefenseTalk

Reducing the head-on radar signature seems to be something rewarding to achieve, to put it mildly. The newest generation AAMs or SAMs should be more capable than previous designs of engaging in an a closing, approaching target shot with an enemy aircraft bearing down on the defender. A single shot may be all one gets.

The newest radar for the F-15s, such as...

AN/APG-70 Radar System

...had better be able to perform to advertised specifications if customers are going to line up for orders. That also goes for the F-22 and F-35.

Fortunately, R&D on systems should proceed as long as money is spent to bring ever-better systems to the field.

Actually the latest radar system I believe is the APG-63v3 or v4. Both are AESA radars instead of mechanically scanned types.

And yes, reducing the head-on signature of the jet offers significant combat advantages but more for the Air to Air BVR type of scenario. Having a lower head on RCS requires the adversary jet to get closer in to detect and lock on to the F-15SE. By then, the SE would have hopefully gotten a shot off and ready to defend against a return shot.

Still, its not as comprehensive as the RCS reduction schemes applied on the -22 and -35. From what I understand, the canted "vertical" stabilizers are going to be removed as well. So much for side-on RCS reduction. Not that it was necessary in the first place.

 

[OPSSG]

The newest radar for the F-15s, such as...

AN/APG-70 Radar System

This is a factually wrong statement - the AN/APG-63(V)3 can be found in F-15SGs and installed in a number of ANG and USAF F-15Cs (see link) - ultimately the Pentagon plans to have 176 “Golden Eagles” in service. The former (V)4 has been redesignated as AN/APG-82(V)1 and used in the F-15E Radar Modernization Program (RMP), which is in it's SDD phase (with IOC in 2014). The above answers are already posted in different threads in this forum, please use the search function.

BTW, there's also a F-15SE thread, read it rather than wiki.

 

[the_big_m_in_ok]

... From what I understand, the canted "vertical" stabilizers are going to be removed as well. So much for side-on RCS reduction. Not that it was necessary in the first place.

I was thinking about that. The Mig-25 and -31 were described as having large outward canted vertical stabilizers to reduce the effects of inertial coupling. And the F-15 has a somewhat similar airframe design.
I have the opinion that with the newest, biggest engines, the F-15SE would still have a low enough wing loading to get high enough at its ceiling to go Mach 3. I think I have the algebraic formulas to prove that at home, but not with me.
The F-22 and F-35 can be compared the same way. My Dad was an aerospace engineer before he retired, so I can try to find the relevant information in one of his college textbooks. They're basic texts, but were written by engineering experts in the 30's and 40's.

 

[Zaphael]

I was thinking about that. The Mig-25 and -31 were described as having large outward canted vertical stabilizers to reduce the effects of inertial coupling. And the F-15 has a somewhat similar airframe design.
I have the opinion that with the newest, biggest engines, the F-15SE would still have a low enough wing loading to get high enough at its ceiling to go Mach 3. I think I have the algebraic formulas to prove that at home, but not with me.
The F-22 and F-35 can be compared the same way. My Dad was an aerospace engineer before he retired, so I can try to find the relevant information in one of his college textbooks. They're basic texts, but were written by engineering experts in the 30's and 40's.

I'm not sure if the MiG-31 and 25's vertical stabilizers can be described as "canted." They look too close to the vertical when compared to the F-117, F-18, F-22 and the recent Iranian abomination of the F-5. Those had really canted vertical stabilizers.

As far as I know, the F-15SE is still rated as a Mach 2.2 fighter or at best Mach 2.5 at altitude. Unlikely that it will achieve 3.0 Mach without some kinda descent. From what I understand, jet engines also have difficulty making Mach 3.0 as the engines themselves become a source of drag.

 

[the_big_m_in_ok]

I'm not sure if the MiG-31 and 25's vertical stabilizers can be described as "canted."

They appear to be canted to me in the perspective view pictures in press releases. The F-15 vertical stabilizers are actually vertical.

They look too close to the vertical when compared to the F-117, F-18, F-22 and the recent Iranian abomination of the F-5. Those had really canted vertical stabilizers.

They're oriented more vertically than the fighters you mentioned, I agree. But they were also fairly large for directional stability at very high altitude flight. That would go for many fighters that can intercept at, say, 60,000'+

As far as I know, the F-15SE is still rated as a Mach 2.2 fighter or at best Mach 2.5 at altitude. Unlikely that it will achieve 3.0 Mach without some kinda descent.

I can try and do that math on that, so for starters:
Basic aerodynamic lift =

V^2 * rho * C(sub)l * S/2

where,
V^2 = forward air velocity in ft/sec squared
rho = air density in 'slugs/cubic ft' at any altitude
C(sub)l = Co-efficient of lift, a small decimal number, usually less than .03 subsonically
S/2 = wing area in sq/ft divided by 2

Now, for the horsepower required to maintain altitude:
Look at the heading 'B.' in this:
UNIFIED PROPULSION 4

My Dad hand-wrote a re-arranged version of the equation in his college textbook margin, but I admit I can't find the book since I moved last. So, here it is from memory:

....... _____________________
...... / ....available (jet gas) HP * 1100
...3 / .....-----------------------------------
....\/ .............C(sub)d * S * V^2

where,
V^2 = the same as above
C(sub)d = Co-efficient of drag
S = wing area as such in Sq. ft.
(Jet gas) HP = Total thrust reacting on the airframe at altitude, times 1100


to determine available HP,

take the forward velocity, divide by 550 and multiply that by available thrust
thus,
(Velocity in ft/sec / 550) * lbs available thrust = available HP

Everything above has the cube root taken of it for the maximum speed at a given altitude.

What I need to do next is research the thrust available at M2.5 an about 50,000-70,000 ft. There were research papers written by undergraduate university students for the annual AIAA aircraft design competition. The information for theoretical interceptors and bombers is there in the 'Web to be abstracted from unclassified data in the paper(s).
I'll do that over the weekend.

Finally,

From what I understand, jet engines also have difficulty making Mach 3.0 as the engines themselves become a source of drag.

They do, yes. But in the case of the J-58 engine of the SR-71, air from the last compressor stage was piped back to the afterburner, thus reducing SFC by---I've read---about 2%. There is a partial way around that.

REEDIT:
Now I have the 'Web references for standard atmospheric rho and another one for a scalable engine performance estimation.

Rho by 1,000 ft intervals to 28K and 2,000 ft intervals to 100k ft:
http://cobweb.ecn.perdue.edu/propulsi/propulsion/flow/stdatm.html

and,

A research paper from Calpoly's aerospace undergraduate program
The Vendetta---Preliminary Design Report
GOOGLize:
"vendetta bomber pdf" --- the first or second hit should be the paper in question.
(There's a substitution in the browser address for Firefox that makes the original address indecipherable.) Google will have to do. Software, you know. I can look for another site that gives a direct 'Web address for downloading.

 

[Marc 1]

Big M, impressive grasp of the subject or aerodynamics and propulsion, but essentially wasted - is there a need for any fighter to have a speed of much over Mach 1.5? I believe accelleration and power to weight ratios are far more relevant than top speed when it comes to fighter design

 

[Zaphael]

Big M, impressive grasp of the subject or aerodynamics and propulsion, but essentially wasted - is there a need for any fighter to have a speed of much over Mach 1.5? I believe accelleration and power to weight ratios are far more relevant than top speed when it comes to fighter design

Thats a damn good question I'm wondering myself.

I know getting past Mach 1.0 for missiles shots are important for reach due to the stiff drag penalties a missile would suffer as it tries to propel itself past the transonic region. With limited fuel on the missile itself, its better to use the aircraft to push past the transonic region for launch.

I can imagine that a Mach 3.0 missile shot would have a really significant energy advantage at launch, but I wonder how much difference that would make for a Mach 4.0 rated missile. To my understanding it would not mean much since the missile would not propel itself much faster than Mach 4.0, despite the available propellant. I guess that would mean the Kinetic energy available for that missile in flight would be pretty much "capped" wouldn't it?

So like you said, I tend to agree that the acceleration to break Mach 1.0 or 1.1 would be more critical than getting the aircraft to Mach 3.0

Aircraft like the Foxbat were designed to intercept the mythical Aurora supersonic bomber at high altitudes. I'm not too clear if that will become a resurrected threat that would require hypersonic interceptors. Interesting thought though it is clear that the F-15 or F-22 aren't designed for speeds greater than Mach 2.5.

 

[localhost127]

on that topic,
what is the form of fuel management on a modern BVR missile?
i understand it is different across platforms, but the AIM-120 for example: it uses max engine output to achieve max velocity/KE from launch, correct? expelling its fuel in a relatively quick time (low number of seconds) ... and from there, relies on that KE for the rest of the flight path.

is there any fuel management on a missile such that launch platform velocity determines how the missile engine operates? e.g. like stated above: launch platform at mach 1 - missile uses max engine output (max fuel usage) to get up to speed as quick as possible.... versus launch platform at mach 3? , where it already is close to max velocity (if missile was rated mach4), and could then burn the engine over a longer period of time due to initial KE?

or does the missile behave the same way regardless of launch platform initial conditions?

 

[Zaphael]

on that topic,
what is the form of fuel management on a modern BVR missile?
i understand it is different across platforms, but the AIM-120 for example: it uses max engine output to achieve max velocity/KE from launch, correct? expelling its fuel in a relatively quick time (low number of seconds) ... and from there, relies on that KE for the rest of the flight path.

is there any fuel management on a missile such that launch platform velocity determines how the missile engine operates? e.g. like stated above: launch platform at mach 1 - missile uses max engine output (max fuel usage) to get up to speed as quick as possible.... versus launch platform at mach 3? , where it already is close to max velocity (if missile was rated mach4), and could then burn the engine over a longer period of time due to initial KE?

or does the missile behave the same way regardless of launch platform initial conditions?

Honestly I have no idea. I would think that newer generation of missiles would include such capabilities in order to maximize fuel efficiency. I think so far, most of the A2A missile designs such as the AIM-120 and R-77 focus on getting out the missile as fast as possible coupled with very low drag designs.

Just to make sure I'm not being misread. I really don't know if missiles like the AMRAAM would do better than Mach 4.0 even if they are released near Mach 3.0 and at altitude. Maybe they can? Maybe they can't due to aerodynamic drag of control surfaces. I am pretty sure however, that the drag from control surfaces together with available fuel and burn rate / time are the main components of the missile that affects its best speed.

 

[the_big_m_in_ok]

Big M, impressive grasp of the subject or aerodynamics and propulsion, but essentially wasted - is there a need for any fighter to have a speed of much over Mach 1.5?

Well, I had to go and look at the 'Web for an unofficial assertion:
http://www.f-16.net/f-16_forum_viewtopic-t-6923.html
(Look at the last post on the page by 'Scrappy'.
Also, I make the point that I have read in a British magazine some time ago that the author of the magazine article made the same point as Scrappy: Namely, the Sam radar can see the F-35/F-22 coming easily enough, but the first shot will probably be the last for that individual site. Then, the fighter would be receding over the horizon toward the target or home. That's why it's claimed supercruising is an effective as a fighter missile defense by itself.

I believe acceleration and power to weight ratios are far more relevant than top speed when it comes to fighter design

Thank you for mentioning that. In my research immediately above, I came across mention of the capabilities of the F-104 by someone who appears to have a lot of technical knowledge of the Starfighter:
Starfighter F-104

The author claimed the F-104 was untouchable while in full afterburner and at very high altitude and could supercruise at least fairly well on dry thrust.

 

[the_big_m_in_ok]

@Zaphael
With respect to Reply #72,
Take a look at this:
AIM-54 Phoenix Missile

An enemy missile like the Phoenix might be a potential threat for even a F-35 in full afterburner at it's absolute ceiling.

Not that I know so much about, say, Russian SAM's but a Phoenix round should be able to merely knock a recon Mig-25 out of the sky by weighing several hundred pounds at burnout and ploughing into the MIG from any direction.

In this case supercruising may not be an advantage. But, I agree ahead of time: That's what Electronic Countermeasures are for, right? I admit I haven't studied that subject because it's usually highly classified, for good reason.



As for the redline speed of the F-35/F-22 duo, that should be officially classified. I still need to get my Sandisk out and look at some NASA Boieng 2707 reports concerning the GE and P&W engines. Performance graphs were given in the reports and they're still on the 'Web.

I'll need to extrapolate the figures for a smaller generic thrust vectored engine that's on those fighters. The officially quoted thrust should be about a maximum of 35,000 lbs at sea level for the Raptor and Lightning II.

 

[Bonza]

@Zaphael
With respect to Reply #72,
Take a look at this:
AIM-54 Phoenix Missile

An enemy missile like the Phoenix might be a potential threat for even a F-35 in full afterburner at it's absolute ceiling.

Not that I know so much about, say, Russian SAM's but a Phoenix round should be able to merely knock a recon Mig-25 out of the sky by weighing several hundred pounds at burnout and ploughing into the MIG from any direction.

In this case supercruising may not be an advantage. But, I agree ahead of time: That's what Electronic Countermeasures are for, right? I admit I haven't studied that subject because it's usually highly classified, for good reason.



As for the redline speed of the F-35/F-22 duo, that should be officially classified. I still need to get my Sandisk out and look at some NASA Boieng 2707 reports concerning the GE and P&W engines. Performance graphs were given in the reports and they're still on the 'Web.

I'll need to extrapolate the figures for a smaller generic thrust vectored engine that's on those fighters. The officially quoted thrust should be about a maximum of 35,000 lbs at sea level for the Raptor and Lightning II.

The AIM-54 isn't in service anywhere (except possibly a few rounds in Iran, assuming they're still in good enough condition to be fired, and that's a big assumption) and from what I understand was designed to intercept high flying Soviet bombers, not fighters and especially not LO aircraft. It probably wouldn't do too well against a manoeuvring, low-observability target. How one would attain a firing solution on an F-35 using the Phoenix while somehow remaining out of reach of the F-35 (and the warfighting system of which it is a part) would be a difficult question to answer too. If your point was more about missiles like the AIM-54 rather than the AIM-54 itself, then I apologise for the unnecessary response.

Also if you're attempting to figure out speed and acceleration and so forth for aircraft, would I be correct in saying that thrust-to-drag ratio is as or more important than thrust-to-weight (I have no idea about these things so was hoping you could tell me, as you seem to understand them)? If so, how do you calculate the drag of a given airframe, along with changes in configuration (pylons, external stores etc)?

 

[Zaphael]

@Zaphael
With respect to Reply #72,
Take a look at this:
AIM-54 Phoenix Missile

An enemy missile like the Phoenix might be a potential threat for even a F-35 in full afterburner at it's absolute ceiling.

Not that I know so much about, say, Russian SAM's but a Phoenix round should be able to merely knock a recon Mig-25 out of the sky by weighing several hundred pounds at burnout and ploughing into the MIG from any direction.

In this case supercruising may not be an advantage. But, I agree ahead of time: That's what Electronic Countermeasures are for, right? I admit I haven't studied that subject because it's usually highly classified, for good reason.



As for the redline speed of the F-35/F-22 duo, that should be officially classified. I still need to get my Sandisk out and look at some NASA Boieng 2707 reports concerning the GE and P&W engines. Performance graphs were given in the reports and they're still on the 'Web.

I'll need to extrapolate the figures for a smaller generic thrust vectored engine that's on those fighters. The officially quoted thrust should be about a maximum of 35,000 lbs at sea level for the Raptor and Lightning II.

I think Bonza has made an adequate reply wrt to the AIM-54 missile. The missile has to be given an initial targeting information via the aircraft fire control radar, and updated by it until the missile has reached a range where its own active radar can take over. That applies for the AIM-120 missile as well.

With the Raptor and hopefully the F-35, they won't be detected at long distances that allow such shots to be taken at them.

When it comes to missile defense, theres definitely more than one approach. Staying out of the missile/threat's weapon engagement zone is one of them. That is where intelligence is needed about the type and capability of the threat. The other is like you said, via ECM, where you flood or spoof their radars with a barrage of noise or false signals, if possible damaging their circuitry completely. And finally, when it comes to an actual shot being taken, speed and acceleration is needed to defeat the missile.

Simply put, a missile regardless of type, will have less fuel than the aircraft its targeting. By running away from a Mach 4 missile at Mach 1.5, the closure rate of the weapon is reduced to 2.5 Mach. And the missile will chase to a point where its own fuel expires, and it relies solely on kinetic energy to reach its target that is fleeing. By applying a series of manuevers, the defending jet can drain away that missiles KE to a point that it can no longer make the intercept. This is why having a lot of acceleration is important; to quickly create that reduced overtake by the missile so that you have time to outlast the missile's fuel. This is the same for both A2A missiles and SAMs. Definitely, there will always be that point in the sky where the jet is simply too close to the threat that no matter how he manuevers, the missile will always have the energy to make the intercept. This is called the no-escape-zone.

Can supercruise be an advantage in missile defense? Yes, but I doubt the pilot will simply be supercruising if a missile shot is coming his way. The balls will go to the wall, in order to buy as much time as possible.

At the end of the day, an aircraft's redline speed is not used reached often even in combat. Mainly because it takes too long to "get there" and it sucks up too much fuel. Hence there is little utility in the "redline" speed unless somethings going really really wrong, I guess you'd be able to understand that since you can sort of imagine the type of curve you'd get if u plot out acceleration in speed vs time graph. Its steep initially, and sort of just tapers out flat before it reaches the redline. That tapering out is not where the acceleration is the most useful, but the nice steep regions before that.

As for scrappy's post, I'm not sure what he was talking about. Most SHORADS or MANPADS I know don't reach up to 60,000ft. That kinda altitude envelope is more common for fixed and semi-mobile ADS systems like the Patriot or S-300s.

 

[the_big_m_in_ok]

I think Bonza has made an adequate reply wrt to the AIM-54 missile. The missile has to be given an initial targeting information via the aircraft fire control radar, and updated by it until the missile has reached a range where its own active radar can take over. That applies for the AIM-120 missile as well.

I admit ignorance to the subject of Russian SAM's in the past, since I thought there was going to be a lot of speculation about something the Russians probably deem more highly classified to their national defense than we do.

With the Raptor and hopefully the F-35, they won't be detected at long distances that allow such shots to be taken at them.

Indeed, yes. ECM can help some if one know the capabilities of Russian SAM radar sets.

And finally, when it comes to an actual shot being taken, speed and acceleration is needed to defeat the missile.Simply put, a missile regardless of type, will have less fuel than the aircraft its targeting. By running away from a Mach 4 missile at Mach 1.5, the closure rate of the weapon is reduced to 2.5 Mach. And the missile will chase to a point where its own fuel expires, and it relies solely on kinetic energy to reach its target that is fleeing. By applying a series of manuevers, the defending jet can drain away that missiles KE to a point that it can no longer make the intercept. This is why having a lot of acceleration is important; to quickly create that reduced overtake by the missile so that you have time to outlast the missile's fuel.

The Americans should be going to great lengths to achieve a goal of both ECM and evasive aircraft actions. I agree.

Can supercruise be an advantage in missile defense? Yes, but I doubt the pilot will simply be supercruising if a missile shot is coming his way. The balls will go to the wall, in order to buy as much time as possible.

Evasions---and especially---afterburners will shorten range. Not a good idea unless the pilot is forced to do that.

At the end of the day, an aircraft's redline speed is not used reached often even in combat. Mainly because it takes too long to "get there" and it sucks up too much fuel. Hence there is little utility in the "redline" speed unless somethings going really really wrong, I guess you'd be able to understand that since you can sort of imagine the type of curve you'd get if u plot out acceleration in speed vs time graph.

I agree with practically everything above. In particular, and to make the assertion, the possible maximum speed of the newest planes and Century Series were higher than advertised, which was intentionally set forth by the Pentagon/Cia/etc. to understate classified info.

Running out of time in this borrowed computer on Sunday. I'll have several hours on Monday evening to get to my calculated "redline" speeds and ceilings of the F-35 and possibly other older planes.

From memory, the J75 of the F-16 would produce 5000 lbs of thrust at Mach 2.5 at 75,000 ft.
(I saw this in either an old book or Gov't report years ago, but it surprised me so much, I never forgot it.)
It's a point of extrapolation for something like a F110, for starters, but I look further.

Got to go.

--Lee