No Escape Zone of Missiles

[mrbsct]

I know No Escape Zones(NEZ) is highly classified, but can anyone make precise calculations on these missiles like

AIM-120 B/C/D
Meteor
R77-1 Adder
R27 Alamo
R37 Arrow

And how does aircraft acceleration and kinematics effect the NEZ? Are missiles even effective after NEZ against a fast maneuvering opponent?

[mrbsct]

Here are my estimates(more guesses)

I read a article saying the AIM-120C was designed to have a "increase I read performance against a 9G opponent." So I believe the AIM-120B can already have those capablities, because NEZ is no always a guaranteed kill, and NEZ is pretty much the maximum range most BVR missiles are effective.

Here are my calculations on NEZ
AIM-120A: 10-20 km(shot down helicopter at 10 km)
AIM-120B: around 30 km
AIM-120C: around 35 km depending on variant
AIM-120D:70 km(50 percent increased range)
Meteor; 90+ km(three times more the NEZ of AIM-120B)
R37E Archer:60 km=("can take on 12 G targets at 30 km, 60 km with 60+- radar")

[basher54321]

The various ranges including NEZ will differ greatly on the targets speed/alt and heading relative to yours - and your current speed and altitude.

A missile fired outside of the missiles indicated NEZ is very effective if the target doesn't know it is coming.

[popcorn]

www.youtube.com/watch?v=r-M_GqSEDDk

[mrbsct]

A missile fired outside of the missiles indicated NEZ is very effective if the target doesn't know it is coming.

but modern missile warning receivers can sense a missile once it launches.

[KamenRiderBlade]

A missile fired outside of the missiles indicated NEZ is very effective if the target doesn't know it is coming.

but modern missile warning receivers can sense a missile once it launches.

How would it do that when it's a passive sensor that listens for signals?
Most radar guided missiles don't activate their radar until the remaining few seconds.
If it's a IR based missile, what other fighter has 360 spherical IR sensors?

[sprstdlyscottsmn]

The missile warning systems being referred too are basically a pseudo-DAS in that they are EO sensors that are looking for launch plume and rocket exhaust.

[blackuday]

NEZ PL-12: 45 km look-up for RCS 3m2 target
NEZ R-27RE: 35 km for type F-16 target
NEZ KS-172/R-27AE: Lock-on range of targets with RCS = 5m2 : 25 km
NEZ R-77: has the 9B-1348E active seeker head, which is stated to have a 16km range against RCS=5m2.
NEZ AIM-120D (AIM-120C8): F-22 AIM-120C8 active Terminal guidance radar seeker of the equipment performance, its small target of RCS is 0.3 square meters can be intercepted at the 12-kilometer, RCS for MiG-31 from 15 to 17 square metres of such large goals can be intercepted at 45 to 50-kilometer.
NEZ SM-6 (rumor): SM-6 max range to 600-700km and NO ESCAPE ZONE to 150km against all known aircraft (excluding SR-71)
NEZ S-400 (rumor): Let's assume if 40N6E's true effective range is 300 km with no escape zone - that is still an amazingly deadly weapon with enormous strategic importance that changes the balance in the pacific.

[wrightwing]

A missile fired outside of the missiles indicated NEZ is very effective if the target doesn't know it is coming.

but modern missile warning receivers can sense a missile once it launches.

That's entirely dependent on the range, at which the missile was fired. If the launch wasn't detected, then the first warning will likely be once the missile goes active. IR detectors may give a slightly improved amount of warning.

[deadseal]

I would take all these numbers as approximations. The fact you are asking online means you will never see the real numbers. Also, how does rcs Impact RTR shots? Just because the queuing might be early or late, that doesn't change the kinematics of the missile. There are so many variables involved to generate MAR, your question could be answered in a thousand ways. Regardless that sh*t is classified, and anyone who tells you a number doesn't really know or is an opsec nightmare

[eloise]

NEZ is the distance where missiles will reach and over take target no matter what the aspect angle of it . It doesnt mean missiles will hit , it just mean the aircraft will have to defeat missiles by maneuver rather than turning and run away . NEZ depending alot on type of target , altitude ,missiles launching speed , however NEZ is about kinematics so it have nothing to do with target RCS
There is a very simple formula that can be used for estimating the performance of a missile. It goes like this :
Change in Velocity (Delta V) = 10 x Specific Impulse x LN (initial weight / final weight) m/s

This assumes that all the fuel is used to get the missile as fast as possible and
none is used to provide just enough thrust to sustain a given velocity.
In otherwords, it assumes an all-boost motor not a boost sustain motor.

For example, let'a take a look at the AIM-120A AMRAAM which we have some decent info on...

Launch weight = 335 lbs (Published stats)
Motor weight = 156 lbs (WPU-6/B HTPB rocket motor weight as per Raytheon)
Approximate specific impulse = 245 seconds (typical of HTPB solid motors)
Approximate fuel fraction of motor = 85% (typical of robust aluminum cased aerospace rocket motors)

OK... if 85% of the motor's mass is the fuel, we have about 132 lbs of fuel in the AMRAAM-A
-- roughly a 39.4% fuel fraction (sounds about right). So let's run the numbers...

Delta V = 10 x 245 x LN(335/(335-132)) = 1227 m/s

The formula predicts that the AMRAAM will go about 1227 m/s (~Mach 3.7) faster than it started.
If it is launched at say Mach 1.5 it'll be going Mach 5.2.
In reality the AMRAAM doesn't go that fast.
The reason is that not all the fuel is used to get it as fast as possible.
The AMRAAM's motor is a boost-sustain design.
It is probably grained to take the weapon to abut Mach 2.5~2.8 faster than it started at
(Mach 4+ in a typical Mach 1.5 release).
The rest of the fuel is shaped to burn much more slowly to keep it's velocity at
or near the achieved maximum out to a longer range before the motor burns out.


Well, for any given fuel fraction and specific impulse,
a designer can decide how fast he wants to go and how long he wants to stay at
or near the peak velocity achieved. For instance, if a missile carries 40% of its launch weight
as fuel and uses the typical a modern HTPB propellant motor, it can:-

(1) Spend 25% to get an approximate Mach 2.1 delta V and 15% on sustaining that speed for a relatively long while.
(2) Spend 30% to get an approximate Mach 2.7 delta V and 10% on sustaining that speed for a shorter while.
(3) Spend 40% to get an approximate Mach 3.8 delta V have no sustain burn time at all.

BTW, on deceleration :
If a missle starts at Mach 4 at burn out and decelerates 25% to Mach 3 after 10~15 seconds,
it WILL NOT decelerate to Mach 2 (another 33% from Mach 3) after 20~30 seconds.
This is impossible because aerodynamic drag (Fd = Cd x A x 0.5 x P x V^2) is a function of
the square of velocity.
As velocity decreases, drag force decreases exponentially in relation to it.
Hence, if the drag for at Mach 4 causes a 25% loss in velocity in 10~15 seconds,
there is no way a much lower drag force at Mach 3 will cause a 33% loss in velocity after
another 10~15 seconds.
What happens is that deceleration is non-linear;
you start off steep and the slope flattens out over time as velocity and hence drag drops.
It'll take a missile a heck of a lot longer to decelerate from Mach 4 to Mach 2 compared to
say Mach 2 to Mach 1 for instance.



Actually it also depends a a lot on altitude (air density)...
Let's put some numbers in:
Question: How much thrust is needed to sustain Mach 3.0 in an AAM like the AMRAAM?

Drag force (Newtons) = 0.5 x P x V^2 x Cd x A

P = Density of Air (kg/m^3) ; ~1.29 kg/m^3 @ sea level; ~0.232 kg/m^3 @ 12,000 m
V = Velocity (m/s) ; Mach 1 = 340 m/s @ sea level; ~295 m/s @ 12,000 m
Cd = Co-efficient of Drag ; ~ 0.6 to 0.95 for rockets depending mostly on finnage,
nose and tail profile
A = Sectional Area (m^2) ; ~ 0.025 m^2 for a 7" diameter missile.

For an AMRAAM like AAM going at high altitudes (40,000 ft)...

Drag Force @ Mach 3 = 0.5 x 0.232 x (295x3)^2 x 0.70 x 0.025 = 1590 Newtons = 357 lbs
Drag Force @ Mach 2 = 0.5 x 0.232 x (295x2)^2 x 0.70 x 0.025 = 707 Newtons = 159 lbs
Drag Force @ Mach 1 = 0.5 x 0.232 x 295^2 x 0.70 x 0.025 = 177 Newtons = 39.8 lbs

The same missile going Mach 3 at Sea Level...

Drag Force @ Mach 3 = 0.5 x 1.29 x (340x3)^2 x 0.70 x 0.025 = 11,744 Newtons = 2640 lbs
Drag Force @ Mach 2 = 0.5 x 1.29 x (340x2)^2 x 0.70 x 0.025 = 5,219 Newtons = 1173 lbs
Drag Force @ Mach 1 = 0.5 x 1.29 x 340^2 x 0.70 x 0.025 = 1,305 Newtons = 293 lbs

Assuming that there is no sustainer,
the deceleration experienced at Mach 3 by the 203 lbs (empty) missile is

Deceleration @ Mach 3 = -F / mass = -1590 / (203 x 0.454) = -17.3 m/s^2 = - Mach 0.059/sec @ 40,000 ft
Deceleration @ Mach 2 = -F / mass = -707 / (203 x 0.454) = -7.67 m/s^2 = - Mach 0.026/sec @ 40,000 ft
Deceleration @ Mach 1 = -F / mass = -177 / (203 x 0.454) = -1.92 m/s^2 = - Mach 0.0065/sec @ 40,000 ft

Deceleration @ Mach 3 = -F / mass = -11744 / (203 x 0.454) = -127 m/s^2 = - Mach 0.39/sec @ sea level
Deceleration @ Mach 2 = -F / mass = -5219 / (203 x 0.454) = -56.6 m/s^2 = - Mach 0.17/sec @ sea level
Deceleration @ Mach 1 = -F / mass = -1305 / (203 x 0.454) = -14.2 m/s^2 = - Mach 0.042/sec @ sea level

OK... enough of the math and the formulas... what does all these mean?
Well, it means that while coasting at Mach 3 an AAM is going to lose about less than 2% of
its velocity a second at high altitudes while it stands to lose about 13% of its velocity at
sea level! Huge difference isn't it?
Remember though that the rate of deceleration actually DECREASES as the
missile's velocity decreases.
It is easy to see that one can claim that a missile can burn out burn out its booster
and sustainer and be effective out to over 100 km at high altitudes or be useful only
against helos after 10km on the deck!

Also, we can make a pretty educated guess as to how much thrust the sustainer has to make.
An AMRAAM class missile with a 400 lbs sustain thrust will be able to stay
above Mach 3 at high altitudes and stay about Mach 1.2 at sea level.
An AMRAAM class missile carrying about 10% of its launch weight as sustainer
grained propellant will be able to keep this level of thrust lit for 20.5 seconds
in addition to whatever the boost time was using the 30% of its fuel to get a
roughly Mach 2.7 Delta V after launch.
A missile like this when fired at Mach 1.5 will reach Mach 4+ and keep
above Mach 3 for the duration of the sustainer at high altitudes.
It will also reach about Mach 2.5 and keep above about Mach 1.2 at sea level.
A motor grained for this thrust profile can have a 10 second boost at ~ 2460 lbs thrust and
a 20 second sustain burn at 400 lbs thrust -- this is a 5:1 boost sustain ratio.
This is also about right for thrust profiles of star grain vs
core burn solid propellant burn rate profiles.




Another rough rule of thumb:-

The time it takes for a missile to lose 25% of its velocity after burn out at supersonic speeds.

Never @ > 100,000 m (~300,000 ft) ; in space
~150 seconds @ 24,000 m (~80,000 ft)
~70 seconds @ 18,000 m (~ 60,000 ft)
~25 seconds @ 12,000 m (~ 40,000 ft)
~10 seconds @ 6,000 ft (~20,000 ft)
~5 seconds @ Sea Level

Remember, fractions over time are not additive.
In otherwords, if a missile loses about 25% of its velocity in 10 seconds,
in the 10 subsequent seconds (t =20s) the missile loses approximately another 25% of
the remaining 75% not a 100%. Total velocity loss is ~43.75% not 50%.

This is highly collated to the fall in air density.
Drag = 0.5 x P x V^2 x Cd x A.
Holding everything else constant Drag falls proportionally to density.
Drag also falls exponentially with Velocity which accounts for the loss in velocity
in the given time slices being about 25% instead of closer to 40%.
So based on the formula above you can estimated NEZ for yourself

[mrbsct]

So what is your estimate of NEZ of AMRAAM at high altitudes?

And when do jets detect an incoming missile? Like the range?

[eloise]

NEZ PL-12: 45 km look-up for RCS 3m2 target
NEZ R-27RE: 35 km for type F-16 target
NEZ KS-172/R-27AE: Lock-on range of targets with RCS = 5m2 : 25 km
NEZ R-77: has the 9B-1348E active seeker head, which is stated to have a 16km range against RCS=5m2.
NEZ AIM-120D (AIM-120C8): F-22 AIM-120C8 active Terminal guidance radar seeker of the equipment performance, its small target of RCS is 0.3 square meters can be intercepted at the 12-kilometer, RCS for MiG-31 from 15 to 17 square metres of such large goals can be intercepted at 45 to 50-kilometer

KS-172, and R-77 lock on range seem realistic , Aim-120D and PL-12 lock on range are too good to be true, To reach the performance you cited, their seeker would need to be more powerful than APG-66 radar which is impossible due to size and power requirements

NEZ SM-6 (rumor): SM-6 max range to 600-700km and NO ESCAPE ZONE to 150km against all known aircraft (excluding SR-71)
NEZ S-400 (rumor): Let's assume if 40N6E's true effective range is 300 km with no escape zone - that is still an amazingly deadly weapon with enormous strategic importance that changes the balance in the pacific.

SM-6 max range is 370 km, 40N6E max range is about 400 km, there is no way 40N6E's NEZ can be 300 km, simply unrealistic

[mrbsct]

There is a difference between look up range and lock on range?

RCS effects NEZ? I thought once the radar has detected them no matter how small they are the missile is going there.

[eloise]

There is a difference between look up range and lock on range?

look up mean radar detection, tracking range again target flying higher than the radar platform, look up range are always longer than look down range because radar are not affected by ground clutter when it looking at target again sky background

lock on range mean the range where missiles seeker aquired a solid lock on target, rather than just detecting it ( lock on range are similar to tracking range, often about 80% of detection range)

RCS effects NEZ? I thought once the radar has detected them no matter how small they are the missile is going there.

RCS affected missiles PK but, it have nothing to do with NEZ, NEZ only show you the range where missiles can overtake target regardless of aspect angle
P/s : did u get the PM?