Weird World War 2 Facts

[wmaxt]

Originally Posted by FLYBOYJ

But that is an internal expense to deliver a product wmaxt. Where the thievery lies is in the spares market. When a government contractor ups spares prices 1000% well, they should be shot!

I agree with the spares/replacement part, I just wanted to point out some of the hidden costs. However if it's a 1 off item without any remaining tooling, allowances need to be made. In construction we have "Time and Materials" clause for things like that.

The other thing is that many times the product costs suddenly get better when a recession threatens cancelation of that product.

wmaxt

[FLYBOYJ]

Originally Posted by wmaxt

I agree, unless it becomes a 1 off item without tooling remaining. In construction we have "Time and Materials" clause for things like that.

wmaxt

Yep - same thing in aircraft manufacturing, and that's reasonable when its put out on the table. Many defense contractors "slip" these ridiculous costs through green procurement "specialists" who don't know the difference between the elbow and arsehole!

[DerAdlerIstGelandet]

LOL I like the way you put that one.

[batsguy]

I am new to this site and an trying to ask if there is any information about a Mark Willey relating to the ME-262?

[evangilder]

That's a bit vague, batsguy. What info do you have and what are you looking for?

[batsguy]

sorry about the Vague...What I understand is that this Mark Willey worked on the Me-262 project...there was a recent (1943) quote about a request by Adolf Hitler for info on the bomb rack implementation on the Jet. Apparently this Mark Willey worked under Herman Goering. I just wanted to know if there was some history on this guy.

[vanir]

I read something about MiG 25 radars, one of the aircraft of which I've got plenty of stats laying around.

How effective was the Mig-25's radar. How far out could it detect enemy aircraft and such not.

Sapfire-25 fire control Radar. Search range 100km. Tracking range 75km. Contained in nose forward of avionics compartment housing RSBN-6S short range navigational radar, SP50 ILS, RVUM radio altimeter and ARK10 radio compass (among other things).

I've also read rabbits were sometimes fried on the runway due to its power. Cold war interceptors especially were designed with very powerful, focused beams due to the advent of countermeasures.

[Nonskimmer]

Focused beams are a standard property of fire-control radars. That's how they function. They illuminate a target for missiles to lock onto. In the case of passive homing missiles, like the old AIM-7 Sparrow, the aircraft's fire-control radar must remain locked onto the target so that the missile can track it. Newer types like the AIM-120 AMRAAM have their own built in active radar. "Fire and forget."

[vanir]

I was under the impression pulse-doppler radars used a pulse and doppler effect rather than outright signal strength to "paint targets" with, overcoming distance and countermeasures obstacles differently.
Just my own assumption, I'm no tech expert on radars.

This includes the assumption early fire-control radars provided a very narrow tracking beam compared to the pulse-doppler, which allowed the advent of "lookdown-shootdown" capability and as avionics evolved, multiple target tracking.

AIM 7's were brought out with the F4, which pioneered pulse-doppler radar for the US air arms, bringing lookdown-shootdown in on the F4N, I think.
Fire control radar was generally used with much earlier IR guided missiles, with typical tracking ranges not more than 5km (MiG 21). The MiG 25 offered 50km range SARH AAM's, typically two carried with two IR AAMs of the same type. As such it was a bit of an oddity using a basic, although very high powered fire control radar with a medium range, radar guided missile. However this system was unreliable enough to maintain the carriage of IR seeker heads on half its MRMs.

Part of the infamous "turkey shoot" against Libyan MiG-23's by US F-15's and F-16's was due to the export MiGs being fitted with the MiG-21's basic fire control radar from its original pulse-doppler, which downgraded their weapons capabilities significantly.

Again, I'm not an expert though and I guess I'm just posting anecdote at best.

[Nonskimmer]

Pulse-doppler radar is used to track targets, yes. But what are generally referred to as "fire-control" radars use the continuous wave principle. That is, they emit a steady, focused, high powered wave that continuously illuminates a target for missiles to lock onto, and in the case of passive homing missiles like the AIM-7, to "track". The missile basically follows the radar wave to the target. Most modern fighter radars employ both functions anyway. Some shipboard radars do too.
Most newer radar guided missiles have built-in active tracking/homing radar that works by pulse-doppler, so this could all just be confusion due to context.

Infrared missiles (IR) use thermal detectors to track an enemy's heat signature. It's not radar.

[Smokey]

Heres an early IR missile, the Messerschmitt Enzian ("Gentian Violet")




http://www.warbirdsresourcegroup.org/LRG/enzian.html
http://www.ctie.monash.edu.au/hargra...many_mess.html
http://www.walter-rockets.i12.com/missiles/enzian2.htm

The first flights which began in May 1944 (1-12), were made to investigate the performance of the power plant, launching units, launch conditions and longitudinal stability.Dr Wurster and Willi Messerschmitt were both certain that Enzian was a viable unit, but the project was cancelled early in 1945, officially coming to a halt on 17th January when a general order stopping work on all projects was issued.

Imagine if this had more investment and went operational in 44.

[vanir]

I was under the impression pulse-doppler radars used a pulse and doppler effect rather than outright signal strength to "paint targets" with, overcoming distance and countermeasures obstacles differently.

Okay so it's unresolved. It'd be interesting to get a handle on this...wasn't there a radar operator or tech on the site somewhere?

Infrared missiles (IR) use thermal detectors to track an enemy's heat signature. It's not radar.

Yes but early fighters like the F-104 and MiG 21 used fire control radars in conjunction with both (often narrow aspect) IR seeker heads and radar linked gunsights in combat. They didn't use radar homing missiles at all. These are typically very short range systems however, since continuous signal strength has a wide range of problems over large distances, namely it disperses and is refracted easily by nothing more than atmosphere and weather.
Early US testing with radar homing missiles was of dubious accuracy, again accepted by military doctrine at ranges of around 5-10km at best until the advent of the pulse-doppler/AIM-7 system.
The F4B I think used early fire control radar in conjunction with AIM-7's but their success rate was marginal compared to early AIM-9's. Pilots celebrated the introduction of the F4N for its ability to use the medium range missiles with some degree of accuracy, aside from the obvious benefits of lookdown-shootdown capability which the earlier fire control radar did not have.
This suggests to me the pulse-doppler and early fire control radar use completely different signals to guide SA radar homing missiles with.

I mean it seems to me with a bit of imagination, a pulse doppler would be different to fire control radar tracking systems in the way its guides missiles thus:
continuous signal strength, disperses widely over short distances and is refracted easily, missile guidence heads (SARH), need to be set not too sensitively so as not to go chasing every cloud that reflects a bit of signal or shooting off when a cold weather patch is crossed. Short range is best (ie. falcon missiles)
pulse-doppler effect, radar pulses are combined with avionics software to identify and range targets across a wider band of signal dispersion, less likely to follow refractions of signals that don't add up to primary target-lock ranging, guidence heads (SARH) can be set more sensitively. Long range should present fewer troubles (ie. sparrow missiles).
But importantly radar search ranges prior to and after the adoption of pulse doppler tracking systems was not significantly altered. Generally when I read "fire control radar" as opposed to "pulse doppler radar" the text is describing the way weapons are delivered by that aircraft's avionics.

[Nonskimmer]

Originally Posted by vanir

Okay so it's unresolved. It'd be interesting to get a handle on this...wasn't there a radar operator or tech on the site somewhere?

Yes there is. Me.

Originally Posted by vanir

Yes but early fighters like the F-104 and MiG 21 used fire control radars in conjunction with both (often narrow aspect) IR seeker heads and radar linked gunsights in combat. They didn't use radar homing missiles at all. These are typically very short range systems however, since continuous signal strength has a wide range of problems over large distances, namely it disperses and is refracted easily by nothing more than atmosphere and weather.

Absolutely true. Early pulse and pulse-doppler radars were and are used for tracking targets as I said. The target lock of an IR missile still depends on acquiring a thermal lock though. No heat signature, no kill. The pulse-doppler radar of the aircraft has nothing to do with the actual missile lock, only the tracking of the target by the aircraft.

Originally Posted by vanir

Early US testing with radar homing missiles was of dubious accuracy, again accepted by military doctrine at ranges of around 5-10km at best until the advent of the pulse-doppler/AIM-7 system.
The F4B I think used early fire control radar in conjunction with AIM-7's but their success rate was marginal compared to early AIM-9's. Pilots celebrated the introduction of the F4N for its ability to use the medium range missiles with some degree of accuracy, aside from the obvious benefits of lookdown-shootdown capability which the earlier fire control radar did not have.
This suggests to me the pulse-doppler and early fire control radar use completely different signals to guide SA radar homing missiles with.

Yes, early test results were highly dubious. Ya got me there.

Originally Posted by vanir

I mean it seems to me with a bit of imagination, a pulse doppler would be different to fire control radar tracking systems in the way its guides missiles thus:
continuous signal strength, disperses widely over short distances and is refracted easily, missile guidence heads (SARH), need to be set not too sensitively so as not to go chasing every cloud that reflects a bit of signal or shooting off when a cold weather patch is crossed. Short range is best (ie. falcon missiles)
pulse-doppler effect, radar pulses are combined with avionics software to identify and range targets across a wider band of signal dispersion, less likely to follow refractions of signals that don't add up to primary target-lock ranging, guidence heads (SARH) can be set more sensitively. Long range should present fewer troubles (ie. sparrow missiles).
But importantly radar search ranges prior to and after the adoption of pulse doppler tracking systems was not significantly altered. Generally when I read "fire control radar" as opposed to "pulse doppler radar" the text is describing the way weapons are delivered by that aircraft's avionics.

Well, like I said, modern active scan homing missiles mostly use pulse-doppler, and modern combat aircraft tend to employ multi-function radar systems utilizing both pulse-doppler and continuous wave (bore sighting) capability. Continuous wave radars do require a very high power setting over a narrow bandwidth to prevent dispersion. That's correct.

The Sparrow missile is guided by CW, not pulse-doppler.

[vanir]

Oh cool. Thanks for the clarification, I've often wondered about that.

[Nonskimmer]

But don't take strictly my word for it.
If you're really that interested in radar theory, the web is full of folks who are far better able (and willing to take the time. ) to go in-depth with it. It really is an interesting field.


Just to give a brief idea:

http://www.radarworks.com/
http://www.radarpages.co.uk/index.htm
http://www.ee.surrey.ac.uk/CE/technical/mod_radar.html
http://www.meteor.wisc.edu/~hopkins/aos100/rad_sum.htm

You may have seen these already, I don't know. These sites aren't devoted to the more modern developments pertaining to military applications, but it gives one a general idea.