By: lukos
- 4th September 2014 at 13:38Permalink- Edited 1st January 1970 at 01:00
Now now... some of your stuff on flight mechanics is... to put it politely... highly questionable.
I think I mathematically justified it pretty well in that thread when talking about climb rate. If I went wrong please point it out.
Lukos,
While I appreciate your critical spirit (cfr. Pascal), you can't expect to get such answers on an open forum. Up to you to believe what is said.
Some members here are known to be reliable an respectable in their field. If you get vague replies from them, be sure they have good reasons to do so.
No need to push.
I realise that, I began by respectfully pointing out that he was wrong as regards AESA only using one frequency per pulse. If that was the case, it would be damn easy to detect.
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By: lukos
- 4th September 2014 at 13:42Permalink- Edited 1st January 1970 at 01:00
Thanks, I would never have been able to find that again.
ok, lukos use a different converter than mine then, i get it to 17.8 nm, if 30 sec even is correct,
but the head on intercept took place 18 km away from the F-16,
so both the shooter & target must then have been on afterburner heading towards each other.
But it also states that each F-16 were carrying 2 external tanks and an ECM pod,
so the 30 sec even sounds more like 'roughly half a minute',
or else i dont know how to make the equation work, cause i dont think the two fighters involved were closing in that fast
Well it says 30s, which at Mach 4, assuming 11,000m altitude is [(30 x 4,248kph)/3600] = ~35.4km or 19nm.
If you think about it though, the missile still spent 30s in flight despite closing, implying that is was fired from more than 19nm away, but the target closed to within that range of the initial release point during flight. But then the missile takes time to accelerate too, however the faster the launch aircraft goes, the faster the missile goes. I read 21.6nm somewhere else but it's ballpark.
Taking your initial figure of 17.8nm, if the MiG was doing 21% of the speed of the missile, it would close from 21.6nm to 17.8nm between launch and impact.
By: MadRat
- 4th September 2014 at 14:05Permalink- Edited 1st January 1970 at 01:00
Software and mid course correction changes make the big difference in range between A/B and the C's.
Call me cynical, but my closing speed in an F-16 is not going to be using the afterburner. AND I am going to be closing to where my breaks off that course are at my best possible corner speed. I'd save my afterburner for an emergency. Not every engagement will involve visual contact. The vast majority of intercepts happen with one aircraft turning away from the other well outside the envelope of your mark 1 eyeball.
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By: lukos
- 4th September 2014 at 14:28Permalink- Edited 1st January 1970 at 01:00
Software and mid course correction changes make the big difference in range between A/B and the C's.
Call me cynical, but my closing speed in an F-16 is not going to be using the afterburner. AND I am going to be closing to where my breaks off that course are at my best possible corner speed. I'd save my afterburner for an emergency. Not every engagement will involve visual contact. The vast majority of intercepts happen with one aircraft turning away from the other well outside the envelope of your mark 1 eyeball.
Going faster increases missile energy and Pk. Whether you loop around depends on the opposition strength and the aircraft you're in. In a stealth aircraft or against superior numbers of enemy aircraft you would loop round. In a large squadron against a few MiGs you would follow in after the AMRAAM forces them to dive on the evasive and then capitalise of the height advantage.
By: swerve
- 4th September 2014 at 14:36Permalink- Edited 1st January 1970 at 01:00
You seem to have a very simplistic view of the defence world. .... An established track record of knowing what you are talking about is what inspires confidence in potential clients. Otherwise, who is going to pay serious money for your services?
.
Simplistic view of any world!
Track record is crucial for anyone working independently, & that means real skills. Bluffers don't survive long.
I was once interviewed for a permanent job, after working freelance for several years, & was asked surprisingly few questions about my technical knowledge. I queried this, & elicited the answer "You wouldn't have lasted as long as you did as a freelancer, & been rehired, if you'd not known your stuff". True, of course, but nice to meet someone who understood it.
By: Amiga500
- 4th September 2014 at 14:51Permalink- Edited 1st January 1970 at 01:00
I realise that, I began by respectfully pointing out that he was wrong as regards AESA only using one frequency per pulse. If that was the case, it would be damn easy to detect.
ugh.
define a pulse...
Is it the waveform emitted instantaneously? Or over 1 second?
If a radar outputs, say, 5kW, that is, 5 kilojoules per second, Merc is pointing out that it is formed of (say), 100x 50joule pulses which all are at distinct frequencies (for an AESA beating at 100 Hz).
As far as I am aware, no current AESA can use half of its T/R modules at one frequency and the other half at another frequency at the same point in time. The whole lot are used, or a subset of the T/R modules are used, and they are beating over very short time periods to give an aggregate over multiple frequencies.
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By: obligatory
- 4th September 2014 at 15:08Permalink- Edited 1st January 1970 at 01:00
Thanks, I would never have been able to find that again.
Well it says 33s, which at Mach 4, assuming 11,000m altitude is [(30 x 4,248kph)/3600] = ~35.4km or 19nm.
no, it says 30 sec,
"It was an instant hit, after a flight of 30 seconds."
i dont know where you are getting 21.6 nm from, can you link to either the converter you are using,
or the source that claim 21.6 nm.
i admit tho that the 30 sec statement sound more like 'some half a minute' statement,
given that the impact occurred 18 km away.
a shame also that no altitude is given, hopefully some better documentation of the event will be investigated
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By: lukos
- 4th September 2014 at 16:07Permalink- Edited 1st January 1970 at 01:00
no, it says 30 sec,
"It was an instant hit, after a flight of 30 seconds."
i dont know where you are getting 21.6 nm from, can you link to either the converter you are using,
or the source that claim 21.6 nm.
i admit tho that the 30 sec statement sound more like 'some half a minute' statement,
given that the impact occurred 18 km away.
a shame also that no altitude is given, hopefully some better documentation of the event will be investigated
Yeah sorry, I did actually use 30 in the calculation as you can see, I will change the 33.
I can't remember where it came from either, it may also have been on F-16.net. If you think about it though, the MiG is closing, so if the missile was launched at 21.6nm range, during missile flight the MiG will close a certain distance (~4nm say), which would account for the difference. 18km may just be a case of ~10nm put into metric units. If we work on the basis of your 17.8nm missile flight after a 21.6nm launch range, then the firing aircraft closes 7.8nm in the time the missile does 17.8nm. Using your 17.8nm that gives an average missile speed of Mach 3.75 (assuming Mach 1 = 1062kph at 11,000m). Which means the launch aircraft was doing just over Mach 1.6.
Average speeds case 1
Missile speed - Mach 3.75
F-16 speed - Mach 1.64
MiG speed - Mach 0.8
But then it could be that the average missile speed was slightly lower and the enemy fighter was slightly faster, meaning the launch aircraft was also slower. E.g.
With current assumptions. MiG's average forward speed was Mach ([3.8 x 3.75]/17.8) = Mach 8 and F-16 speed was Mach 1.6. However, if MiG was doing Mach 1.2, it instead closes 5.7nm of the 21.6nm, leaving the missile flight distance at 15.9nm, meaning the F-16 covered 5.9nm, giving:
Average speeds case 2
Missile speed - Mach 3.35
F-16 speed - Mach 1.24
MiG speed - Mach 1.2
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By: obligatory
- 4th September 2014 at 16:45Permalink- Edited 1st January 1970 at 01:00
no way an F-16 with 2 external tanks and an ECM pod go M1.64, and unlikely M1.24, pending on alt which is duly lacking,
as is speed, this is really poor documentation on the event.
the most probable is 30 sec is derived from 'not sure but roughly ~1/2 minute'
By: FBW
- 4th September 2014 at 18:07Permalink- Edited 1st January 1970 at 01:00
no way an F-16 with 2 external tanks and an ECM pod go M1.64, and unlikely M1.24, pending on alt which is duly lacking,
as is speed, this is really poor documentation on the event.
the most probable is 30 sec is derived from 'not sure but roughly ~1/2 minute'
Depending on Alt, believe it or not, an F-16 with a drag index of 120 or so ( 2 600 gallon tanks, lantirn targeting pod, 4 AMRAAM, est. drag index depending on where stores are carried) will do between 1.3 and 1.5 mach at 30,000ft depending on weight.
Anyone have a more detailed account of the shootdown?
EDIT- oops, they were carrying ECM pod, not LANTIRN (I'll check the drag index for listed pods)
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By: obligatory
- 4th September 2014 at 18:27Permalink- Edited 1st January 1970 at 01:00
we arent even told the altitude, half of this group were carrying A2G weapons, so i dont think they were at 30k ft,
yes, it'd be great to get some actual documentation on this event
By: MadRat
- 4th September 2014 at 18:28Permalink- Edited 1st January 1970 at 01:00
Closing at Mach anything makes your aircraft a brilliant heat source and radar reflector. Honestly, I think your F-16 is going to close ranks at 450-ish knots and your average MiG is going to be doing about the same. Your engine sfc is double on wet thrust and if you're running high throttle its around 4X the fuel usage at best cruise velocity. You're not closing at Mach speeds if you plan to make it home. Air combat just isn't done above Mach.
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By: obligatory
- 4th September 2014 at 18:36Permalink- Edited 1st January 1970 at 01:00
well, except if youre about to kill someone, or someone are about to kill you,
i dont doubt that the F-16 increased speed for the shot, but the MiG ?
the mig probably didnt know it was fired at, or it would not have been a head-on shot,
so why would it be on a/b ?
By: mig-31bm
- 4th September 2014 at 18:41Permalink- Edited 1st January 1970 at 01:00
well, except if youre about to kill someone, or someone are about to kill you,
i dont doubt that the F-16 increased speed for the shot, but the MiG ?
the mig probably didnt know it was fired at, or it would not have been a head-on shot,
so why would it be on a/b ?
may be it prepared to launch its R-77 too
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By: obligatory
- 4th September 2014 at 18:45Permalink- Edited 1st January 1970 at 01:00
possible, the awac monitored the mig from take off so there should be info
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By: lukos
- 4th September 2014 at 20:29Permalink- Edited 1st January 1970 at 01:00
ugh.
define a pulse...
Is it the waveform emitted instantaneously? Or over 1 second?
If a radar outputs, say, 5kW, that is, 5 kilojoules per second, Merc is pointing out that it is formed of (say), 100x 50joule pulses which all are at distinct frequencies (for an AESA beating at 100 Hz).
As far as I am aware, no current AESA can use half of its T/R modules at one frequency and the other half at another frequency at the same point in time. The whole lot are used, or a subset of the T/R modules are used, and they are beating over very short time periods to give an aggregate over multiple frequencies.
That isn't the case. A pulse is a short burst, many of which are emitted per second. AESA pulses can contains several frequency components, spreading the emission power across the spectrum, so that they are very difficult to detect, unless you know the spread.
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By: lukos
- 4th September 2014 at 20:48Permalink- Edited 1st January 1970 at 01:00
no way an F-16 with 2 external tanks and an ECM pod go M1.64, and unlikely M1.24, pending on alt which is duly lacking,
as is speed, this is really poor documentation on the event.
the most probable is 30 sec is derived from 'not sure but roughly ~1/2 minute'
C1-12 & http://www.f-16.net/forum/viewtopic.php?p=188248
2 370gal tanks DI = 2 x 35 = 70
2 wing tip AMRAAMs DI = 0
For some reason I can't find the ALQ-131 pod but let's assume it's rough LANTIRN-like (DI=3)
C1-8
4 further AMRAAMs DI = 16
B8-73
DI=100, Mach 1.64 at 30,000ft.
Don't know if I calculated that right.
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By: lukos
- 4th September 2014 at 20:59Permalink- Edited 1st January 1970 at 01:00
Closing at Mach anything makes your aircraft a brilliant heat source and radar reflector. Honestly, I think your F-16 is going to close ranks at 450-ish knots and your average MiG is going to be doing about the same. Your engine sfc is double on wet thrust and if you're running high throttle its around 4X the fuel usage at best cruise velocity. You're not closing at Mach speeds if you plan to make it home. Air combat just isn't done above Mach.
By: MadRat
- 5th September 2014 at 06:27Permalink- Edited 1st January 1970 at 01:00
Missile launch at 30km, impact when target is 18km away. So the gap closed 12km between the shot and impact. If each were closing at the same speed they each went 6km before impact and the missile went 24km in the same span of time. The fighters were subsonic. The missile was Mach 4 and traveled four times the distance.
Pretty cut & dry. The fighters were not flying supersonic.
By: Hotshot
- 5th September 2014 at 07:40Permalink- Edited 1st January 1970 at 01:00
The AMRAAM would probably not reach mach 4 if launched at low altitude, and if it flies at low altitude, it would slow down much faster than at high altitude.
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By: lukos - 4th September 2014 at 13:38 Permalink - Edited 1st January 1970 at 01:00
I think I mathematically justified it pretty well in that thread when talking about climb rate. If I went wrong please point it out.
I realise that, I began by respectfully pointing out that he was wrong as regards AESA only using one frequency per pulse. If that was the case, it would be damn easy to detect.
Posts: 1,760
By: lukos - 4th September 2014 at 13:42 Permalink - Edited 1st January 1970 at 01:00
Thanks, I would never have been able to find that again.
Well it says 30s, which at Mach 4, assuming 11,000m altitude is [(30 x 4,248kph)/3600] = ~35.4km or 19nm.
If you think about it though, the missile still spent 30s in flight despite closing, implying that is was fired from more than 19nm away, but the target closed to within that range of the initial release point during flight. But then the missile takes time to accelerate too, however the faster the launch aircraft goes, the faster the missile goes. I read 21.6nm somewhere else but it's ballpark.
Taking your initial figure of 17.8nm, if the MiG was doing 21% of the speed of the missile, it would close from 21.6nm to 17.8nm between launch and impact.
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By: MadRat - 4th September 2014 at 14:05 Permalink - Edited 1st January 1970 at 01:00
Software and mid course correction changes make the big difference in range between A/B and the C's.
Call me cynical, but my closing speed in an F-16 is not going to be using the afterburner. AND I am going to be closing to where my breaks off that course are at my best possible corner speed. I'd save my afterburner for an emergency. Not every engagement will involve visual contact. The vast majority of intercepts happen with one aircraft turning away from the other well outside the envelope of your mark 1 eyeball.
Posts: 1,760
By: lukos - 4th September 2014 at 14:28 Permalink - Edited 1st January 1970 at 01:00
Going faster increases missile energy and Pk. Whether you loop around depends on the opposition strength and the aircraft you're in. In a stealth aircraft or against superior numbers of enemy aircraft you would loop round. In a large squadron against a few MiGs you would follow in after the AMRAAM forces them to dive on the evasive and then capitalise of the height advantage.
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By: swerve - 4th September 2014 at 14:36 Permalink - Edited 1st January 1970 at 01:00
Simplistic view of any world!
Track record is crucial for anyone working independently, & that means real skills. Bluffers don't survive long.
I was once interviewed for a permanent job, after working freelance for several years, & was asked surprisingly few questions about my technical knowledge. I queried this, & elicited the answer "You wouldn't have lasted as long as you did as a freelancer, & been rehired, if you'd not known your stuff". True, of course, but nice to meet someone who understood it.
Posts: 2,163
By: Amiga500 - 4th September 2014 at 14:51 Permalink - Edited 1st January 1970 at 01:00
ugh.
define a pulse...
Is it the waveform emitted instantaneously? Or over 1 second?
If a radar outputs, say, 5kW, that is, 5 kilojoules per second, Merc is pointing out that it is formed of (say), 100x 50joule pulses which all are at distinct frequencies (for an AESA beating at 100 Hz).
As far as I am aware, no current AESA can use half of its T/R modules at one frequency and the other half at another frequency at the same point in time. The whole lot are used, or a subset of the T/R modules are used, and they are beating over very short time periods to give an aggregate over multiple frequencies.
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By: obligatory - 4th September 2014 at 15:08 Permalink - Edited 1st January 1970 at 01:00
no, it says 30 sec,
"It was an instant hit, after a flight of 30 seconds."
i dont know where you are getting 21.6 nm from, can you link to either the converter you are using,
or the source that claim 21.6 nm.
i admit tho that the 30 sec statement sound more like 'some half a minute' statement,
given that the impact occurred 18 km away.
a shame also that no altitude is given, hopefully some better documentation of the event will be investigated
Posts: 1,760
By: lukos - 4th September 2014 at 16:07 Permalink - Edited 1st January 1970 at 01:00
Yeah sorry, I did actually use 30 in the calculation as you can see, I will change the 33.
I can't remember where it came from either, it may also have been on F-16.net. If you think about it though, the MiG is closing, so if the missile was launched at 21.6nm range, during missile flight the MiG will close a certain distance (~4nm say), which would account for the difference. 18km may just be a case of ~10nm put into metric units. If we work on the basis of your 17.8nm missile flight after a 21.6nm launch range, then the firing aircraft closes 7.8nm in the time the missile does 17.8nm. Using your 17.8nm that gives an average missile speed of Mach 3.75 (assuming Mach 1 = 1062kph at 11,000m). Which means the launch aircraft was doing just over Mach 1.6.
Average speeds case 1
Missile speed - Mach 3.75
F-16 speed - Mach 1.64
MiG speed - Mach 0.8
But then it could be that the average missile speed was slightly lower and the enemy fighter was slightly faster, meaning the launch aircraft was also slower. E.g.
With current assumptions. MiG's average forward speed was Mach ([3.8 x 3.75]/17.8) = Mach 8 and F-16 speed was Mach 1.6. However, if MiG was doing Mach 1.2, it instead closes 5.7nm of the 21.6nm, leaving the missile flight distance at 15.9nm, meaning the F-16 covered 5.9nm, giving:
Average speeds case 2
Missile speed - Mach 3.35
F-16 speed - Mach 1.24
MiG speed - Mach 1.2
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By: obligatory - 4th September 2014 at 16:45 Permalink - Edited 1st January 1970 at 01:00
no way an F-16 with 2 external tanks and an ECM pod go M1.64, and unlikely M1.24, pending on alt which is duly lacking,
as is speed, this is really poor documentation on the event.
the most probable is 30 sec is derived from 'not sure but roughly ~1/2 minute'
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By: FBW - 4th September 2014 at 18:07 Permalink - Edited 1st January 1970 at 01:00
Depending on Alt, believe it or not, an F-16 with a drag index of 120 or so ( 2 600 gallon tanks, lantirn targeting pod, 4 AMRAAM, est. drag index depending on where stores are carried) will do between 1.3 and 1.5 mach at 30,000ft depending on weight.
Anyone have a more detailed account of the shootdown?
EDIT- oops, they were carrying ECM pod, not LANTIRN (I'll check the drag index for listed pods)
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By: obligatory - 4th September 2014 at 18:27 Permalink - Edited 1st January 1970 at 01:00
we arent even told the altitude, half of this group were carrying A2G weapons, so i dont think they were at 30k ft,
yes, it'd be great to get some actual documentation on this event
Posts: 4,951
By: MadRat - 4th September 2014 at 18:28 Permalink - Edited 1st January 1970 at 01:00
Closing at Mach anything makes your aircraft a brilliant heat source and radar reflector. Honestly, I think your F-16 is going to close ranks at 450-ish knots and your average MiG is going to be doing about the same. Your engine sfc is double on wet thrust and if you're running high throttle its around 4X the fuel usage at best cruise velocity. You're not closing at Mach speeds if you plan to make it home. Air combat just isn't done above Mach.
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By: obligatory - 4th September 2014 at 18:36 Permalink - Edited 1st January 1970 at 01:00
well, except if youre about to kill someone, or someone are about to kill you,
i dont doubt that the F-16 increased speed for the shot, but the MiG ?
the mig probably didnt know it was fired at, or it would not have been a head-on shot,
so why would it be on a/b ?
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By: mig-31bm - 4th September 2014 at 18:41 Permalink - Edited 1st January 1970 at 01:00
may be it prepared to launch its R-77 too
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By: obligatory - 4th September 2014 at 18:45 Permalink - Edited 1st January 1970 at 01:00
possible, the awac monitored the mig from take off so there should be info
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By: lukos - 4th September 2014 at 20:29 Permalink - Edited 1st January 1970 at 01:00
That isn't the case. A pulse is a short burst, many of which are emitted per second. AESA pulses can contains several frequency components, spreading the emission power across the spectrum, so that they are very difficult to detect, unless you know the spread.
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By: lukos - 4th September 2014 at 20:48 Permalink - Edited 1st January 1970 at 01:00
B8-81 - Mach 1.3 at 30,000ft even with maximum DI.
http://info.publicintelligence.net/HAF-F16-Supplement.pdf
C1-12 & http://www.f-16.net/forum/viewtopic.php?p=188248
2 370gal tanks DI = 2 x 35 = 70
2 wing tip AMRAAMs DI = 0
For some reason I can't find the ALQ-131 pod but let's assume it's rough LANTIRN-like (DI=3)
C1-8
4 further AMRAAMs DI = 16
B8-73
DI=100, Mach 1.64 at 30,000ft.
Don't know if I calculated that right.
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By: lukos - 4th September 2014 at 20:59 Permalink - Edited 1st January 1970 at 01:00
WVR isn't, BVR most definitely is.
Here's another source. Appears the story came from Jane's originally going by links at bottom.
http://kosova.org/post/Operation-Allied-Force-How-Dutch-F-16AMs-shot-down-a-Mig-29
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By: MadRat - 5th September 2014 at 06:27 Permalink - Edited 1st January 1970 at 01:00
Missile launch at 30km, impact when target is 18km away. So the gap closed 12km between the shot and impact. If each were closing at the same speed they each went 6km before impact and the missile went 24km in the same span of time. The fighters were subsonic. The missile was Mach 4 and traveled four times the distance.
Pretty cut & dry. The fighters were not flying supersonic.
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By: Hotshot - 5th September 2014 at 07:40 Permalink - Edited 1st January 1970 at 01:00
The AMRAAM would probably not reach mach 4 if launched at low altitude, and if it flies at low altitude, it would slow down much faster than at high altitude.