Guided anti-aircraft missiles - possible?

[wuzak]

Rocketry was being advanced quite well in Germany in the latter stages of WW2, but largely the funding went to the V-2.

There were several surface to air missile developments, some unguided and some guided by ground stations.

I was wondering if it would have been possible for the FuG 227 Flensburg radar detection system to be mounted in a suitable SAM, enabling it to guide the weapon to target.

The FuG 227 Flensburg detected the Monica tail warning radar of British bombers. This was discontinued when a German night fighter landed in the UK, was inspected and the detection equipment discovered.

Did the 8th AF use a similar tail warning radar?

 

[wiking85]

Why would they during daylight operations? They could see people all around them, which the Brits couldn't at night.
I think the best thing would have been to a guided missile from the ground with a proximity fuze, assuming the Germans could get one operational, using it to detonate the missile when it closed in on the bomber box, rather than rely on the reflexes of the operator to detonate it before it shot past the box. One just needed to get the missile pointed in the right direction and once near the target it could detonate itself.

 

[davebender]

Rockets per se aren't the problem. Germany mass produced solid fuel diglycol artillery rockets during 1941. They could certainly build a diglycol powered anti-aircraft rocket.

Guidance system good enough to hit a moving aircraft is another matter. There were plenty of German experiments using IR, acoustic and radar guidance but the technology wasn't ready for mass production during WWII.

 

[silence]

The Germans did have the Ruhrstal X-4 wire-guided AAM that was in testing stages at the end of the war and apparently there is some possibility they may have been used.

The warheads had a 7m proximity fuse activated acoustically and tuned to the frequency of a B-17 engine. It had about a four mile range but really needed a second man in the cockpit to guide it effectively.

 

[wuzak]

Thinking more of surface to air missiles.

A good guided SAM would, surely, be more effective than anti-aircraft guns?

 

[silence]

I'm not sure. The best naval surface FC radar was, as I recall, about +/- 25m or so in range accuracy and less in bearing accuracy. Dunno if that's close enough without having to use a ridiculously large fragmentation warhead.

Then there's the cost of missiles and launchers vs. guns and shells.

 

[parsifal]

SAMs and AAMs are perhaps the most difficult gudance systems to develop, after ABM systems. SSMs are a relatively simple excercise by comparison

I have no idea if the germans had the potential to develop effective SAMs and AAMs. But I do note that even though both the allies and the Soviets had access to German research, it was some time after Korea was it not, before any nation had "effective" guided missiles. i say "effective" very loosely....the early versions of sidewainder had hit probabilities of about 15% (it did vary a lot), Ive read this had improved to about 20-25% in the 60's (during Vietnam)

Soviet early missiles were very poor in terms of accuracy.

Why would german techs be any different

 

[davebender]

A good guided SAM would, surely, be more effective than anti-aircraft guns?

That depends on your definition of "good".

AA missiles and associated equipment to make them work tend to be expensive. Probably need an accuracy of at least 5% to make them cost effective. Can that be achieved with WWII technology?

Alternately, how much can heavy AA gun accuracy be improved using a similar amount of development money? Germany was experimenting with high velocity APFSDS AA guns to shorten projectile flight time and thereby increase accuracy. Add an effective proximity fuze to the shell and accuracy might be as good as a primitive AA missile.

And the final option. Germany could place Jumo 004A jet engine into mass production during 1943. More expensive then Jumo 004B engine which entered mass production during fall of 1944 but it might be money well spent. A couple of full strength jagdgeschwader equipped with Me-262s could do a lot of damage to daytime heavy bombers.

 

[silence]

I think the APFSDS shell would have a much smaller charge for a given caliber, reducing both its kill radius and kill power - assuming a prox. fuse.

 

[parsifal]

I'm not sure. The best naval surface FC radar was, as I recall, about +/- 25m or so in range accuracy and less in bearing accuracy. Dunno if that's close enough without having to use a ridiculously large fragmentation warhead.

Then there's the cost of missiles and launchers vs. guns and shells.

Missiles like Terrier or the American Standard Missile need to detonate within about 50m to have a 30% chance of a kill, but are quite small as fart as arhead size is concerned . They basically use specialised ballistics to achieve this. the missile is rotating on its axis when detonated. When it detonates, it sends out a concentrated "spiral" of elongated shrapnel that for a time travels through the air, rather like the propellor arms of an aircraft. In that way, the probability of a hit is much enhanced. i doubt the Germans would have been aware or able to produce that effect in 1945, which means their kill radii for SAMs would have been a lot less, or, as you say a missile of very large size .

The point about this is that it is not radar accuracy that is necessarily the dominant constraint affecting AA effctiveness, its the effective kill radiius of the ordinance as well, and postwar, a lot of additional changes were made with missile techs to improve that lethality.

 

[davebender]

10.5 cm ?Sabot? Type H. E. Shell « Catalog of Enemy Ordnance
That doesn't mean it will be too small to be effective. For instance German 10.5cm light howitzer sabot round employed an 8.8cm projectile.

Do something similar with 10.5cm Flak 38 and the 8.8cm projectile should have a muzzle velocity in excess of 1,000 meters per second. With a highly streamlined shell and proximity fuze you should have decent accuracy vs heavy bombers cruising straight and level @ 180mph. However you must pour enough money into development to fix the technical glitches.

 

[silence]

Missiles like Terrier or the American Standard Missile need to detonate within about 50m to have a 30% chance of a kill, but are quite small as fart as arhead size is concerned . They basically use specialised ballistics to achieve this. the missile is rotating on its axis when detonated. When it detonates, it sends out a concentrated "spiral" of elongated shrapnel that for a time travels through the air, rather like the propellor arms of an aircraft. In that way, the probability of a hit is much enhanced. i doubt the Germans would have been aware or able to produce that effect in 1945, which means their kill radii for SAMs would have been a lot less, or, as you say a missile of very large size .

The point about this is that it is not radar accuracy that is necessarily the dominant constraint affecting AA effctiveness, its the effective kill radiius of the ordinance as well, and postwar, a lot of additional changes were made with missile techs to improve that lethality.

FWIW, here's what Wiki has to say:

German efforts (Surface-to-air missile - Wikipedia, the free encyclopedia)

The first serious consideration of a SAM development project was a series of conversations that took place in Germany during 1941. In February, Friederich Halder proposed a "flak rocket" concept which led Walter Dornberger to ask Wernher von Braun to prepare a study on a guided missile able to reach between 50 and 60,000 feet altitude. von Braun became convinced a better solution was a manned rocket interceptor, and said as much to the director of the T-Amt, Roluf Lucht, in July. The directors of the Luftwaffe flak arm were not interested in manned aircraft, and fighting broke out among the various teams. This served to delay serious consideration of a SAM for two years.[5]

Von Axthelm's concerns of 1942 led to serious consideration of the flak problem for the first time, and initial development programs for liquid- and solid-fuel rockets were part of the Flak Development Program of 1942.[6] By this point more serious studies by the Peenemünde team had been prepared, and several rocket designs had been proposed, including 1940's Feuerlilie, and 1941's Wasserfall and Henschel Hs 117 Schmetterling. However, none of these projects saw any real development until 1943, when the first large-scale raids by the Allied air forces started. As the urgency of the problem grew, new designs were added to the mix, including Enzian and Rheintochter, as well as the unguided Taifun which was designed to be launched in waves.[7]

In general, these designs could be split into two groups. One set of designs would be boosted to altitude in front of the bombers and then flown towards them on a head-on approach at low speeds comparable to manned aircraft. These designs included the Feuerlilie, Schmetterling and Enzian. The second group were high-speed missiles, typically supersonic, that flew directly towards their targets from below. These included Wasserfall and Rheintochter. Both types used radio control for guidance, either by eye, or by comparing the returns of the missile and target on a single radar screen. Development of all these systems was carried out at the same time, and the war ended before any of them was ready for combat use. The infighting between various groups in the military also hurt development. Some extreme fighter designs, like the Komet and Natter, also overlapped with SAMs in their intended uses.

Albert Speer was especially supportive of the missile development. In his opinion, had they been consistently developed from the start, the large scale bomber raids of 1944 would have been impossible.[8]

 

[Balljoint]

It would seem that rocketry and FLAK had, for the most part, similar shortcomings. The salient need for both was a proximity fuse. Also, radar control would have enhanced both appreciable. Hindsight from the Viet Nam experience suggest that these capabilities greatly enhanced both with the edge perhaps going to radar-controlled massed AAA in that detection of the radar painting wasn't of much help vs. the advantage of knowing a SAM is coming. As it was, at night, FLAK was ganged and guided by a searchlight illuminating a target plane. Replace the light with radar and add a proximity fuse and bombing, either day or night, would have been in deep trouble.

Infrared self-guiding missiles during the war had two major shortcomings relative to the later Sidewinder. IR transparent windows required single crystals, water soluble materials or poor optical properties with polycrystalline materials. Also, though you'd think they could figure it out, German missiles attempted to "steer" towards the target which lead to a "chasing" path. As most pilots know, a constant bearing provides a collision course between moving objects.

With the benefit of hindsight, given the proper priorities, it would seem that proximity fuses and higher resolution radar were doable –though I will defer on the radar to anyone with a better grasp of the extant technology of the time.

 

[Shortround6]

Even in the 1950s most 'radar aimed' missiles used on radar to track the target and another to track the missile and a computer/director ( computer could be analog) to 'steer' the missile to the target. US Navy missile Cruisers were limited to the number of targets they could engage not by the number of launchers or firing rate of the missile launchers but by the number of missile tracking/controlling radars on board. Launch a new missile and you have to give up control of a missile already in flight. It took a while (years) to get the radar receiver in the missile good enough to pick up reflected radar waves from the target with the target "painted/illuminated" by the high power ship radar. This is semi-automatic homing. Full homing is when the missile carries it's own transmitter. Many of the early missiles were command homing. It took years (a decade or more?) to get the Navy missiles to live up to their advertising. The chances of the Germans getting a 'working' missile in use by 1945??? pretty low.

 

[wuzak]

I am not talking about active radar homing, but passive homing on radar signals.

The Luftwaffe was already using such a device in 1944 to home in on the RAF's tail warning radar at night.

My question is was the equipment too large for use in a missile, too expensive and could they get the electronics to talk to the guidance system?

 

[davebender]

Germany had radar guided searchlights and heavy flak by 1941.

12.8 cm FlaK 40 - Wikipedia, the free encyclopedia

Compared with the 88mm FlaK 18 36, the 128 used a powder charge four times as great which resulted in a shell flight time only one-third as long. This made aim against fast-moving targets much easier.

I think German heavy flak was on the right path with radar guidance and shorter shell flight times. Add a proximity fuze and the 12.8cm Flak 40 is probably all you need for knocking down WWII era heavy bombers.

 

[Shortround6]

What you lack is the pilot. The Pilot could interpret a simple display on scope or screen and steer his aircraft accordingly. Blip left or right of center line or above or below horizontal line for elevation. Converting display signal to commands to the Missile control surfaces is a lot harder. Especially as the same amount of distance form the center line requires different control inputs depending on the range to the target (shown by size of blip?or other display?) or you get over control or under control depending on distance.

 

[stona]

My question is was the equipment too large for use in a missile

Much too large, unless you are talking about a very big missile. There would be a need to put the antennae somewhere too. If you look at the well known photograph of the "Woodbridge" Ju 88 the long antennae projecting, one from each wing, are what we are looking at.

The FuG 227 wasn't fitted to aircraft until about a year before the end of the war and didn't work terribly well. I can't see it being developed for use in a missile (which also needed to be developed) before the end of the war, or even in the 1940s. It's an enormous technological leap forward, there's a reason why nothing like it was seen for many years, despite the benefit of all the German research (492 German rocket scientists and technicians were officially employed in the US) and the impetus of the cold war.

The relatively primitive "wasserfall" system suffered a fatal blow with the bombing of Peenemunde, with the death of the man in charge of developing the propulsion system, Dr Thiel.

Cheers

Steve

 

[fastmongrel]

Even in the mid/late 70s Surface AA missiles werent very reliable. We had our Bofors L70s taken away and replaced with Rapier that the keen chaps with brass hats called a Hittile because it was so accurate. I remember sitting and watching as a Rapier battery pulled up and got all its equipment laid out for a practise shoot against a Drone. there was an awful lot of starting up generators laying out cables setting up computers getting the Rapier set up dead level it took about half an hour but it was all done just in time for the Drone.

The Drone pottered into view at about 150mph the Rapier started to track the Drone and when it was in range WHOOSH off went a Hittile that missed and I dont mean just missed it missed in the Columbus aimed for China and got as far as Hispaniola miss. Round went the Drone again and this time WHOOSH it missed again. The red faced Rapier boys packed up and went away muttering about the bad weather and the fact that there were trees too near for the radar to get a proper lock. The old Bofors L70s would have got set up in about 2 minutes flat and chopped the Drone into scrap with the 1st 3 rounds.

Our CSM was standing behind me and said "Oh gosh we are jolly well doomed if old Johnny Russki comes along in a jet plane loaded with guns and rockets you lovely lot had better learn how to dig slit trenches in a jolly old hurry" Or something like that I might have missed out an expletive or ten.

 

[tomo pauk]

So you are the AAA guy too, Fast?
Back in the time of Brotherly Republics, all of the 'light AA' units (regiments, basically) were of mixed layout - eg. my regiment have had 4 batteries of SP 30mm, 2 batteries of towed three-barreled 20mm guns and one battery (don't know how many 'firing teams' worth) of Strela-2M (SA-7, shoulder-launched SAM). The another 'AA division' (sorta mini AA regiment) located in our barracks was outfitted with 2 ZSU-57 and 2 batteries of Strela-1 (SA-9, self propelled IR homing missile launcher).
The Bofors L70 was a highly regarded AA cannon back then, especially when controlled by the Girrafe radar.