Germany develops in-flight refueling.

Only works if the British are utterly stupid. The patrol planes aren't going to be "drawn off", they will continue to patrol, thus U-boat "wolf-packs are pretty helpless unless fortunate enough to be directly in the path of the CVE's course. So you think the KM and Luftwaffe could afford to fight a major sea battle every time they wanted to launch, undetected, a strike of VLR aircraft over the Atlantic? How long before they run out of naval ships and aircraft?

Is that the one sub-titled "The Luftwaffe's Ill-fated Campaign"?

Yeah, assuming they now EXACTLY where the convoy is. Without radar and without being able to sight it visually, how do they do that? The CVE's radar will be able to pick them up at about 100 miles, unless of course they are flying very low (which means they will have even less chance of sighting any convoy). Either way, the advantage goes to the Convoy/CVE because they will know the bearing the attackers are approaching on and will have a very good idea of the position long before the bombers can attack.

 

Should I keep going in this thread, where things seem to be splitting between two points of view:

1) large, organised, fighter escorted raids setting out.

Or

2) the single, unescorted, (but MAR, DT equipped) bombers that fly a little further than historically, before getting shot down.

Should I make a new thread that deals with my concept solely (large, escorted raids), or keep on here where things getting a bit confused? There still seems some confusion about CH having any effect at all, and I'm tired of making posts that people fail to understand and then make me go back and correct their posts with the facts made clear already.

So what do you guys say? Make a thread that spells out things in the OP and is defined and specific right from the get go, or just keep muddling on here?

 

If the CVE patrol planes won't intercept the Condors, then they fail at their basic mission of preventing them from getting into the Atlantic. Meanwhile the Condor is going to be able to radio back the location of the CVE group/Convoy. The biggest problem with the Uboats is they had no strategic surveillance to guide them to the target...they would spend 5 out of every 6 days blindly searching for anything with hydro phones that could pinpoint convoys at 100km range under ideal conditions [more likely 1/2 that range] and they rarely got more than one action per 6 week sortie. Even if the Condor reports are off by 100miles, its better than just groping around in the dark for weeks on end.

Yes

The normal cruise & Attack altitude of the Condor was ~4km. But cloud cover could easily be 1-3km. The best detection range the CVE could get would be 100km and often more like 50km....so right in the sweet zone allowing them to pass through this 'picket' with out much difficulty.

Unless you didn't get my post, radar ranges are a 'hope and a prayer ' at this time in history. The range and accuracy can change from hour to hour and at altitude.... It could be cut in half . So between Radar ineffectiveness and the gaps in the coverage due to the curvature of the earth, it would be more a case of 'if' they detect the condors, not when.

I remember a modern tale of a Phantom pilot practicing passes on the Ark Royal at night in a light storm in the seventies. The Carrier Air Search Radar didn't even see the Phantom until it was 1 mile away, after the pilot told him were to look. Whats it Dowding said...'Counting on god and praying for Radar'.

 

Just keep it as is. All missions would be tried. For example Condors doing long range surveillance , while Ju-88 with long range tanks and this notional inflight refuel are dispatched to attack convoys based on Condor reports.... as are Uboats Wolfpacks and surface flotillas....etc

 

Not really. The basic mission of any ships, CVE's or radar pickets, would be to report the strikes so that long range fighters from Britain could intercept them before they were able to get out to sea. It doesn't really matter if the Germans know the position of the ships because, unless they want to provoke a major air-sea battle there's not a thing they can do about them.

You are correct that the U-boats were badly hampered by their inability to find Allied convoys, but you are wrong about the Kondors solving that problem. First you have to operate a huge number of Kondors out over the Atlantic to find all, or even most, of the convoys. And the problem of imprecise over-water navigation then comes into play. Historically, the Kondor crews seldom knew where they were and their position reports only confused and distracted the U-boats. Again and again, Kondors chanced upon convoys and radioed their "positions", but were so far off navigationally, that the U-boats never found the convoys (Blair, "Hitler's U-boat War", Vol. 1). And no, bad position reports were not better than groping aroud in the dark because the U-boats would chase after the phantom position reports at top speed hoping to find and attack a convoy, only to use up precious fuel that much faster, and subsequently have to abort their patrols sooner than they otherwise would have.

And during the period envisioned (mid-1940 to mid-1941) there were seldom enough U-boats at sea (an average of between 6 and 9 U-boats) to even attack all the Allied convoys that were at sea even if they could have found them. So the maritime recconnasaince would have been largely wasted if the object was to get U-boats in conact with convoys.

There are documented cases of shipborne radar in 1940-42 picking up incoming aircraft raids as far out as 100 miles in the Pacific. And that was with radar less sophisticated than the British had. I guess the Germans will just have to take the chance that they MIGHT not be picked up until they were 50 or 25 miles away. The point is that with radar pickets in the Bay of Biscay, AND radar equipped CVE's with the convoys, the Allies have a much better chance of finding the strike formation first. Especially since the Germans did not have airborne (AVS equivalent) radar until the Spring of 1942.

In fact, launching a strike would be suicidal without first achieving a positive sighting of a convoy. And the only way the strike formation could then hope to find the convoy (remember the bad position reports?) would be if the patrol plane maintains contact and broadcasts a homing beacon. But then it's likely that the CVE's figters would be able to find it, either by radar, or by homing on the beacon. How many hours would elapse between the sighting of a convoy and the arrival of a strike formation? It would be many hours and that would give the CVE pilots plenty of time to work with.

There are all sorts of ancedotal tales of the eccentricities of radar; the Battle of the pips, etc. But the fact is, it was generally reliable and more often than not gave the Allies a significant advantage during and after WW II, especially where they had it and their adversaries did not.

 

I don't care if it's a new thread or not, but I for one would like to hear the details of exactly how this in-flight refueling technology would be used to advantage.

What would a typical mission profile look like? Would the patrol planes use in-flight refueling or just the strike planes? How would the strike formations be vectored onto a convoy contact? Would they be orbiting out over the Atlantic, waiting for a convoy position? Or would they be launched only when a convoy was located? How many planes (patrol, strike, tankers and A/SR) would be committed to this duty. Where exactly, would the refueling rendezvous be set? Where would the planes be based? How would the strike planes attack? High level, low level, torpedoes, bombs?

Finally, I would like some explanation of how the historical unwillingness of the Luftwaffe to support thr KM would be overcome, and how the Germans would produce all these extra multi-engine aircraft? You haven't answered that last question yet, though I posed it some time ago.

 

During the period in question there were very few ships below cruiser size that had radar. By mid 1941 about 195 British Destroyers had radar but thats at the end of that period. I don't think any Destroyers had radars in mid 1940..they were just coming out in late 1940. Those had short range sets of maybe 40-50km.

Most of these CVE we have been discussing, don't even materialise until 1942. As I recall the first problems the Condors experinced air intercept was in mid 1941 from the first British CVE that had just put to sea.Perhaps you are thinking of the CAM ships? So there is no time to set up this so called picket system. I don't think lone radar picket warship would survive long, with Uboats in near by water.

At Crete in spring of 1941 , the LW did alot of damage to the RN fleets in the area and almost all of those ships and radar sets and included a RN Carrier. RN fleets operating to close to Spain or Norway [<500km] in mid 1941 would suffer the same fate as in Crete 1941.

And I would not put the chances of any long range RAF interceptors based out of the UK at finding anything, without airborne radar and even then, they were very short range sets. In real weather conditions, its still a 'needle in a haystack' search.

As to the poor reporting of the LW condors, there was no historical cooperation between KM and LW due to Goering stubornness. Remove the LRP from Goerings control [Via Hitler] and that could very well have developed. And you are wrong, even a vague sighting report is better than no sighting report at all. I remind you, they don't have to find all the convoys just enough to make a difference.

As to CVE have field day with UBoats. I looked through the records of UBoats lost at sea and from 1939 to 1941, only 10 were lost from the air, 7 were from long range planes and only 3 by carrier aviation. Thats out of 68 Uboats lost in those years , about 15% to air attack and 4% to carrier aviation.

In 1942 the figures are 23 sunk by long range patrol plane and 3 by carrier aviation. It doesn't look like carrier aviation was much of a threat back then. Even overall in 1942 about 86 UBoats were lost , of which 30% by air however carrier aviation only accounted for 3%.

It seems like Carrier aviation threat to Uboats is hardly worth mentioning in the early years.

 

Ok, I will try to explain my reasoning for wanting a separate thread.

This thread, started by BEARPAW, only posited the use of mid air refueling. He did see that there might be a 'time and place' where this technology might have been potentially useful to the Germans. What he posted was hitting the UK over their whole island, flying across the Atlantic to bomb the USA, or flying all the way across the USSR to bomb the Ural Mountain passes. Nothing was said, one way or another, about when the decision would be made to try this out. Then I made my mistake.

What I did, and I apologise for this (I get enthusiastic when reading what if's that involve new ideas), was to take just the part about the MAR, and tie that into DT, air raiding the merchantmen, having FW 187's as long range fighter escorts going with the bombers (and others escorting the tankers), and all the rest. It was my idea that this change would take place (for the sake of exploration of a 'best case' scenario for seeing what these technologies might have been like) before the war even begins (read as: 1935 the planes are getting built, and well before even this, the idea is born and embraced), and that this then sets the pace for the rest of the discussion. As this isn't my thread, it really isn't my place to 'high-jack' the thread so to speak, and I really didn't intend to get people confused.

Because this isn't a thread that I started, I feel that we are getting off topic a bit, discussing my ideas, and that some people might not be to happy with the way the thread is getting cluttered up with back and Fourths (some of which is even more OT than my input).

I would like to make a new thread, the OP of which could serve as a recap of the things we covered in the 4 pages of this thread, but all in one post (I would just sift thru all 4 pages and try to get the on topic issues listed out for ease of reading, and then we would all of us be on the same sheet of music.

This last post, where good questions are asked that need and deserve good answers, cannot really be answered here, as this thread didn't have anything to do with these things. It was my uncontrolled enthusiasm for this idea that led me to insert all the other stuff, with the result of confusing people. I definitely don't want people to be offended if I ignore their points brought up in their posts, especially when it's my fault for causing the confusion in the first place.

I think that this thread, which definitely contributed to my knowledge of WWII (for instance, I'd never heard of 'chain home' before it was mentioned in here, despite seeing a movie where German troops with explosive backpacks ran up to the transmitters, got shot, and took them out), inspired some good input from several members of the WW2F.com community. I want to continue the exploration of the whole alternate strategy thing, but honestly believe that if we are going to do so, it would be better to make a clean, clear start in a new thread.

Would you guys participate in a thread that takes an admittedly unhistorical look at what might have been, if Germany had taken a different view of, and attempted remedy for, her strategic situation?

 

Just a bit of info, for carrier ops as ASW, in the early days of WWII.

But some British naval officers, and particularly the First Lord of the Admiralty, Winston Churchill, sought a more ‘offensive’ strategy. The Royal Navy formed anti-submarine hunting groups based on aircraft carriers to patrol the shipping lanes in the Western Approaches and hunt for German U-boats. But this strategy was deeply flawed because a U-boat, with its tiny silhouette, was always likely to spot the surface warships and submerge long before it was sighted. The carrier aircraft were little help. Although they could spot submarines on the surface, at this stage of the war they had no adequate weapons to attack them. Any submarine found by an aircraft was long gone by the time surface warships arrived. The hunting group strategy proved a disaster within days. On September 14, 1939, Britain’s most modern carrier, HMS Ark Royal, narrowly avoided being sunk when three torpedoes from U-39 exploded prematurely. U-39 was promptly sunk by the escorting destroyers, becoming the first U-boat loss of the war. Failing to learn the lesson, another carrier, HMS Courageous, was sunk three days later by U-29.

After this, the carriers were withdrawn from ASW duties.

 

It's very difficult. The surface flotilla would probably be intercepted by other RN units before it even got close. The same is true for the Condors. Note that I proposed a string of pickets with at least 2 CVEs backing them up. Uboats tended to not live long around a CVE group.

The aircaft would be intercepted by fighters from the closest CVE. Either or both could launch a strike at the surface ships as well if they got close enough. The RN had plenty of surface forces other than the pickets we are talking about to go after KM surface ships as well. A CVE and even a couple of escorts is in any case not a sitting duck for a few U-boats. As has been pointed out said wolf pack would constitute most if not all the U-boats at sea at the time and even if it didn't take serious losses it wouldn't be going after merchant ships during this period.

Is it? That's not been my experiance. Indeed I've seen ships tracked at about that range with radar.

If it weren't for the picket line in front of them.

Pretty variable at times it's 0 m.

Why wouldn't the CVE's be able to detail a couple of fighters to go after the Condors. Then there's the question of whether or not the Condors even see the CVEs and what good it's going to do them to radio back the approximate location of them even if they do.

Where did you get this? At this altitude they aren't going to see much over the North Atlantic any time but summer and at times not even then. Plus the Condor tended to attack from very low levels. Low enough that rifle caliber mgs presented a signifcant threat.

Except we're not relying on the CVE to detect the planes. And note I said the pickets were about 100 miles apart. This means that they are only required to look out to a range of about 50 miles. If you plug that into the radar horizon calculator along with a mast height of say 20 meters you'll find that the planes have to fly under 250 m to get under the radar horizon of the pickets. I wouldn't want to be flying that low in bad weather over the Atlantic.

While altitude and range could effect the probability of detecting a target something as large as a Condor or a large group of planes are going to be pretty easy to spot at under 50 miles.

If you can push up a very difficult technology we should be able to push up the time scale of a counter technology that was much closer to fruition and easier to do. But again it only takes a few ships with radar to push the picket line far enough out to make it completely usless to try and evade.

The question is range vs what? 40-50 km vs a single fighter may well translage to something like 100 km or more vs something like a Condor or a whole bunch of planes.

Uboats weren't particuarly effective vs warships but especially if cruisers are used as pickets escorting them wouldn't be too much of a problem.

The British didn't for the most part take serious damage at Crete until they were out or almost out of AA ammo. In this case they'd head back to port before that happened. If the LW and KM are devoting a large effort to elliminating this picket line then they aren't devoting it elsewhere and the losses they take attacking the line may well prove to be prohibitive. Especially to the Condors and Uboats.

I don't recall RN units near Spain suffering any severe losses. The same is true of Norway.

How does the cooperation or lack there of affect the quality of the reporting?

Oh how does a report saying there's ships in the North Atlantic help? Sighting reports only help if they can be acted on and they also tend to give away intelligence as well as produce it. Then there's the question of how the subs are going to recieve it? Are they going to be sitting on the surface waiting for radio reports?

That's because you aren't looking at the total picture. Hunter killer groups did a real number on Uboats but it was often the escorts that got the kills. The planes would spot the subs, somtimes damage them, and direct the escorts to them.

 

That is because the RN, Like the USN, had a policy of installing radars on the most valuable ships first; carriers, battleships, cruisers. But there was no technological reason radars couldn't be installed on destroyers or even smaller vessels in 1939 or 1940. There were even British prototype airborne sets being tested in 1940. This is a what-if; if the British had determined that they had a need for radar sets in destroyer type ships in 1939-40, they would have installed them. As for the range of such sets, I believe it was much in excess of 40-50 KM. I'd appreciate it if you would back up your assertions with some documentation.

Again, this is a what-if. If you grant to the Germans use of technology they never even developed, then you have to understand that the British could develop counter technology (which they did eventually build) earlier than historically. You are contending that the Germans would be able to spring this hypothetical in-flight refueling technology as a complete surprise in 1940, but that is totally unrealistic. Such technology, to be useful requires a long lead time, much development and production of hardware of hardware, flight testing, training of pilots, etc. This could hardly go unnoticed by a country at war with Germany. The most likely assumption is that Britain would know Germany was testing in-flight refueling technology and that the Allies would be preparing counters to it's possible uses.

Your opinion that U-boats would be able to efficiently destroy radar pickets and other ASW vessels is not borne out by historical data. And it is especiallly not true in 1940, when Germany was able to keep just a handful of U-boats at sea. The available U-boats could attack merchant ships or they could be deployed against radar pickets, but even the vaunted German U-boats couldn't be in two places at once.

I seriously doubt it. Most of the damage inflicted on RN vessels at Crete occuured while the ships in quetion were immobilized loading troops being evacuated from Crete, and then the most serious damage was only done once the vessels in question had exhausted their AA ammo. Neither situation would apply to the radar pickets operating close (<500 Km?) to either France (not Spain) or Norway.

Of course, you wouldn't because you don't realize such fighters would only be scrambled when surface radar had established contact with enemy strike formations. The surface radars would vector the fighters into contact much as the "Chain Home" system worked historically in 1940. In bad weather conditions the strike formations would have trouble finding their refueling tankers, so it's likely only good weather situations would occur. Bottom line, the long range British fighters would have avery good chance of thwarting refueling mission out of France

Actually, there was. (see; Air support by Luftwaffe units for U-boats in WWII)

As for bad position reports, is it your assertion that erroneous position reports which cause the U-boats to race about burning their fuel up and finding nothing is better than staying on their patrol station and hoping to spot something? Admiral Donitz didn't think so; he complained bitterly about the phantom convoys that the Luftwaffe fliers reported because they frequently led to U-boats aborting their patrols early with nothing to show but a lot of expended fuel.

You are partially correct. The earlier air attacks on U-boats were not very effective for a couple of reasons. Many of the attacking aircraft were not equipped with depth charges but aeraial bombs. These were practically useless for attacking a diving sub. Then when areial depth charges were introduced, they used the standard detonators which ad settings designed for surface use, i.e. they assumed the U-boat would be below 100 feet in depth. In fact, when planes attacked a U-boat, it was only after sighting it on the surface and the U-boat was in the act of crash-diving, seldom being below 50 feet in depth. The answer, of course was to equip aerial depth charges with triggers with settings of 25 to 50 feet. This simple change was accomplished in a matter of weeks after the British realised the problem. They also substitued a more powerful explosive, Torpex, at the same time, making the charges about 50% more powerful.

These changes, of course, could have been made at any time and the British would have realized their necessity that much sooner had U-boats been more effective in their attacks. Since this is a what-if, it's not unreasonable to assume that a change in German technology would have changed the time-frame of the British response.

But even these changes weren't necessary to reduce the effectiveness of the U_boats. Loss due to aircraft is onlt one mearsure of the effectiveness of CVE's against U-boats. It isn't necessary to sink a U-boat to destroy it's effectiveness against surface vessels. Forcing a U-boat to submerge and keeping it submerged effectively deprives the U-boat of it's ability to attack most surface ships because it is so much slower underwater, Aircraft routinely were able to accomplish this and that fact must also be taken into account when assessing the role of the CVE.

Unless, of course, you are a German U-boat skipper. Donitz mentioned the advent of CVE's as one of the top three reasons the battle of the Atlantic was lost.

 

It wouldn't even take that. Just a few more earlier ineffective attacks by planes which this what if would provide and the problem is defined and thus well on the way to being solved. The scenario that seams to be evolving would actually render the u-boats less effective as they are now trying to chase warships. In these circumstances I'm pretty sure DA and I are in agreement as to just how effective that would be.

 

Yes, I would agree. Given the very small number of German operational sea-going U-boats in 1940, it seems this scheme would require all of them to be dedicated to just countering the likely British response. When the fundamental idea is for U-boats to sink Allied merchant ships, it doesn't make any sense to commit all of the available U-boats to chasing after radar pickets and CVE escorts. It would simply result in more U-boat losses and fewer Allied ships sunk.

The scenario seems to be evolving in two directions; The first is that in-flight refueling would allow bombers to make attacks on Allied convoys somewhere in the Atlantic to the west of Britain (which was done historically anyway). The second is that somehow, in-flight refueling would somehow improve the Luftwaffe's ability to provide reconnaissance allowing German U-boats to find more Allied convoys.

The first concept would have allowed bombers to range further into the Atlantic, however, it's certain that had German bombers in large numbers begun to attack Allied convoys well out to sea, the British response would have been to escort the at risk convoys with carriers. The problems which the advocates of this idea need to resolve are;

1. The Germans had insufficient numbers of aircraft (both bombers and tankers) to sustain this kind of campaign and insufficient production capability to produce the necessary numbers.

2. There was no way for Germany to predict weather in the mid-Atlantic, thus pilots would be flying into unknown wethaer conditions which would hamper the effectiveness of their attacks and produce high attrition rates.

3. Precision over-water navigation would be required to falciltate refueling and locate the convoys. No such technology existed to make this possible and historically, this negated much of the reconnaissance value of the German long range maritime missions.

4. Until the spring of 1942, Germany deployed no effective airborne radar which would have been necessary for efficient maritime searches.

5. In-flight refueling was slow and inefficient during the period and would have exposed the very vulnerable tanker aircraft to atacks by Allie long range fighters.

The second scenario, improving the recconnasiance value of the German patrol bombers sufferes from several unresolved problems.

1. In the period when it could have been feasible, the KM had few U-boats to take advantage of the improved recconnaisance potention. Often there were just six to nine U-boats at sea and these were not enough to assign even one U-boat to each Allied convoy at sea.

2. The lack of any precision navigation technology historically produced situations where convoys sighted were seldom at the positions reorted by the German aircrewws. This led to wasteful and inefficient use of U-boats chasing phantom convoys and using up precious fuel for no gain. Until this problem could be solved, in-flight refueling offers no advantages for the U-boats.

3. The political will of the Luftwaffe was not focused on providing support for the KM. Any use of Luftwaffe planes for this purpose would reduce the air support available for the German Army and for air operations against Allied air forces. It's questionable whether this choice would make ny sense to the German high command. Thge question that is raised, is could Germany afford the resources and effort required to urilize in-flight
refueling?

In-flight refueling technology was almost universally known by the world's air forces well prior to WW II, yet during that conflict no belligerent air force attempted to develop it, or use it operationally.

WHY?

The answer seems to be that it did not provide sufficient advantages to offest the disadvantages of requiring additional resources, specialized aircrew training, specialized aircraft, the potential for high attrition rates of both planes and pilots, and the requirement of sophisticated communications and flight planning. The fact is, historically, Germany did not see any worthwhile advantages to using in-flight refueling, so before I am willing to entertain any possibiliy of an alternative history, I would like to know what the departure point is? What chaged hsitorically to make the German Luftwaffe think otherwise?

 

Yes, I would agree. Given the very small number of German operational sea-going U-boats in 1940, it seems this scheme would require all of them to be dedicated to just countering the likely British response. When the fundamental idea is for U-boats to sink Allied merchant ships, it doesn't make any sense to commit all of the available U-boats to chasing after radar pickets and CVE escorts. It would simply result in more U-boat losses and fewer Allied ships sunk.

The scenario seems to be evolving in two directions; The first is that in-flight refueling would allow bombers to make attacks on Allied convoys somewhere in the Atlantic to the west of Britain (which was done historically anyway). The second is that somehow, in-flight refueling would somehow improve the Luftwaffe's ability to provide reconnaissance allowing German U-boats to find more Allied convoys.

The first concept would have allowed bombers to range further into the Atlantic, however, it's certain that had German bombers in large numbers begun to attack Allied convoys well out to sea, the British response would have been to escort the at risk convoys with carriers. The problems which the advocates of this idea need to resolve are;

1. The Germans had insufficient numbers of aircraft (both bombers and tankers) to sustain this kind of campaign and insufficient production capability to produce the necessary numbers.

2. There was no way for Germany to predict weather in the mid-Atlantic, thus pilots would be flying into unknown weather conditions which would hamper the effectiveness of their attacks and produce high attrition rates.

3. Precision over-water navigation would be required to facilitate refueling and locate the convoys. No such technology existed to make this possible and historically, this negated much of the reconnaissance value of the German long range maritime missions.

4. Until the spring of 1942, Germany deployed no effective airborne radar which would have been necessary for efficient maritime searches.

5. In-flight refueling was slow and inefficient during the period and would have exposed the very vulnerable tanker aircraft to attacks by Allie long range fighters.

The second scenario, improving the reconnaissance value of the German patrol bombers suffers from several unresolved problems.

1. In the period when it could have been feasible, the KM had few U-boats to take advantage of the improved reconnaissance potential. Often there were just six to nine U-boats at sea and these were not enough to assign even one U-boat to each Allied convoy at sea.

2. The lack of any precision navigation technology historically produced situations where convoys sighted were seldom at the positions reported by the German aircrews. This led to wasteful and inefficient use of U-boats chasing phantom convoys and using up precious fuel for no gain. Until this problem could be solved, in-flight refueling offers no advantages for the U-boats.

3. The political will of the Luftwaffe was not focused on providing support for the KM. Any use of Luftwaffe planes for this purpose would reduce the air support available for the German Army and for air operations against Allied air forces. It's questionable whether this choice would make ny sense to the German high command. The question that is raised, is could Germany afford the resources and effort required to utilize in-flight
refueling?

In-flight refueling technology was almost universally known by the world's air forces well prior to WW II, yet during that conflict no belligerent air force attempted to develop it, or use it operationally.

WHY?

The answer seems to be that it did not provide sufficient advantages to offset the disadvantages of requiring additional resources, specialized aircrew training, specialized aircraft, the potential for high attrition rates of both planes and pilots, and the requirement of sophisticated communications and flight planning. The fact is, historically, Germany did not see any worthwhile advantages to using in-flight refueling, so before I am willing to entertain any possibility of an alternative history, I would like to know what the departure point is? What changed historically to make the German Luftwaffe think otherwise?

 

From Clay Blair's "Hitler's U-boat War", Vol. 1, pages 232-236.

"In conformance with Hitler's personal order, Luftwaffe Gruppe 40, based in Bordeaux, commenced convoy-spotting in January, [1941]... An average of two Condors per day patrolled the area near Rockall Bank. The airmen found convoys on January 11, 16, and 20, but owing to the unfavorable weather, the scarcity of U-boats, and the incorrect position reports from the Condors, Godt [in command in Donitz's temporary absence] was not able to put a single boat in contact with any of the convoys...When it was discovered that the position reporting from the Condors could not be relied upon, the airmen were directed to shadow the convoys and send beacon signals to home in the boats."

"Another six boats sailed in the second half of January; four from Lorient...and two from Germany.....These boats, too, found poor hunting. The Condors spotted convoys on January 26, 28, and 30, but owing to failures in communications and other factors, none of the U-boats could be brought into play."

"Counting six new boats that were to sail from Germany, Donitz had eighteen boats to deploy in February. Notwithstanding the terrible weather and the paltry returns of January, he insisted that the bulk of the boats should operate in the North Atlantic in cooperation with the Condors employing the so-called improved communications procedures...[Donitz] believed the Condor reconnaissance flights near Rockall Bank had forced the British to divert convoys well to the north to avoid aerial detection. Later, when the OKM released the boats of the submarine trap [aimed at RN units operating in that area], he left six boats on patrol lines due south of Iceland. Since this area was beyond the range of Bordeaux-based Condors, Donitz requested that Condor flights be staged to that area from Norway."

"the diversion of Condors to the U-37/Hipper operation and a decision to put Condor crews through a crash course in navigation and communications delayed the staging of these aircraft from Norway. Hence, the boats hunting south of Iceland had no help from the Condors for many days. They found no convoys, but several of them picked off lone ships and convoy stragglers in heavy weather."

"Finally, on the afternoon of February 19, a lone Condor staging from Norway found a convoy, Outbound 287. Donitz ordered five boats to converge on the position and Gruppe 40 to send out more Condors at first light the following morning. But the operation was a failure. Three Condors reached the area, but all gave different positions, leading to the belief that that a second or perhaps even a third convoy had been detected. Adding to the confusion, B-dienst picked up distress calls from a ship reporting a Condor attack in yet another position. One boat, Lehmann Willenbrock's U-96 homed on a Condor beacon signal, came upon the convoy in foul weather, and sank a straggler, the 7,000 ton British Tanker Scottish Standard. But no other boats could find the convoy."

 

One of the main reasons may be the aircraft most in need of it were single engine fighters. There are tremendous safty problems with air to air refueling prop planes in general and single engine fighters in particular. You really don't want to hit a fuel probe with a prop. For WWII aircraft to do it well would have required designing the system into both the tanker aircraft and the recieving aircraft which means at least major modifications of both.

 

Excellent points that I hadn't thought of.

The "looped hose" method used by the USAAF in the 1920's required that the hose be connected to the fuselage at a point behind the cockpit. The hose had to remain "looped" or slack to keep it from fouling the plane's prop(s), so not much pressure could be used in pushing the fuel through the system, making it a slow process.

It now occurs to me that refueling prop planes would require different processes for single engine and multi-engine aircraft.

 

From 1939-1942 the Germans produced 179 FW 200 and another 84 in 1943-44, however I don't think the KM got hold of more than 10 at a time from Goering... so no more than 3 could be used at any given patrol. In 1942 the HE-177 came out and 166 where built followed by another 980 in 1943/44. So the LW could have devoted the bulk of the FW-200 to KM maritime surveillance and kept the He-177 for themselves.

There were 279 BV 138 and 71 Do 18 plus 128 He 115 seaplanes all built between 1939-1942 to do essentially the same mission.

The BV 138 weight in at 11,000kg ; had a 4000km range and used three Jumo Diesel engines.

The Do-18 weight in at 5850kg ; had a 3500km range and used two Jumo Diesel engines.

The He-115 weight in at 6690kg ; had a 3300km range patrol and 2000km carrying a torpedo and used two BMW engines.

FW-200 weight in at 12,950kg ; had a 4400km range patrol and 3300km carrying a bomb load of 2100kg and used four BMW engines.


So roughly the production of two He 115 could have been exchange for the production of another FW-200. That raises the FW 200 production from 1 to 27 in 1939 & from 36 to 74 in 1940, and the 1943/44 figures go up from 84 to 154.

So they could have had up to 250 FW-200 built between 1939-1942 to support and mount convoy attacks from the start of the war. Infact given economy of scale they probably could have topped out at ~370-380 FW-200 by the end of 1942.


BTW you can't possibly suggest we generalising from a single incident with the Condor -Uboat combination????

 

This is not necessarily true and is very likely untrue. First the "exchange" rate is not linear. It is expotential. The exchange rate is closer to 4 to 1 rather than 2 to 1. As aircraft went from one to two to four engines their production rate falls roughly as an inverse square function.
Second, dropping production of a Henkel aircraft in favor of a Focke Wulf one does not necessarily mean that the necessary tools, jigs, production space, etc., are available to produce extra aircraft. For instance about mid-war the Luftwaffe wanted to reinstate production of the Henschel Hs 123 ground attack biplane. This is found to be impossible to do because Henschel had scrapped all the tooling and jigs for production. Replacing these would have taken too long and been too costly to do so the idea was dropped.
Third, the pre-war Fw 200 and early war Fw 200 models were largely unsuited to use as maritime patrol and bomber aircraft. In point of fact, in May 1940 there were only six (6) available Fw 200C-0 bombers available and on strength with 1/KG40. Of these only two (2) were servicable. By September 1940 1/KG 40 had 15 Fw 200C-0 and C-1 on hand. These could carry just 4 250 kg bombs and had a servicability rate of about 25%.
Lastly, the early Fw 200 models used as bombers suffered alot of mechanical and structurial problems that slowed production due to extensive modifications to fix them. Included in these were: Engine fires, landing gear collapse and, fuselage failure. Lack of armor and defensive armament proved major problems. The lack of carrying capacity and the external mounting of the bombload were issues that needed addressing too.

Aside from these problems, if the Germans were truly interested in having a capable maritime partol aircraft for long range missions from the start of the war the Fw 200 certainly would not have been their first choice. As a strictly military combat aircraft it was mediocre at best. Yes, for a while against little or no opposition it scored some singular successes. Only lack of a suitable replacement in sufficent numbers prevented its withdrawal from service.

 

No, a single incident really doesn't prove anything and I never suggested that it does

But six separate convoy contacts between January 11 and January 30 where the Condors were not able to bring a single U-boat into action, and a seventh on February 19, where only one U-boat managed to make contact based on a Condor homing beacon, despite the fact that there were five U-boats in the vicinity, certainly does seem to indicate a trend. And that trend does not portend well for Condor/U-boat cooperation. In fact, Blair goes on to report numerous other instances where imprecise navigation on the part of both aircraft and U-boat crews continually led to missed contacts and wasted fuel.

The basis of that trend, as I have repeatedly pointed out, was a lack of precision over-water navigation technology. This was not something that was exclusively a German problem, but plagued every air force that operated aircraft on long over-water flights during WW II. The advocates of in-flight refueling have repeatedly ignored this issue, but before in-flight refueling could be considered of practical use during the time period, the problem will have to be convincingly addressed.