Aerial Refueling

[FLYBOYJ]

Operating procedures and tactics needed to be developed based on the doctrine of the day. I'm sure there were many leaders in the 8th AF who were well aware of the pre war attempts to introduce air to air refueling and after the war and into the cold war years, this operation was developed and utilized based on the need to send bombers thousands of miles to hit their targets. In later years fighters were introduced into the picture.

I believe that during WW2, the pace of the conflict out weighed development in some areas that could have been achieved much earlier and this is one of them.

 

[davebender]

That could work to RAF advantage.

The Spitfire was very capable but had a short combat radius. Put the aerial refueling point over the North Sea about 50 miles from the English coast. Surround it with a cloud of about 500 Spitfires which are otherwise being wasted on Circus raids over the French coast. Both sides have long range radar coverage of the region so the command control playing field is level. If JG2 and JG26 want to come out and play they will be badly outnumbered.

 

[Crimea_River]

1 Lancaster - 22000 lb bomb capacity equates to about 3000 US gal of gas.

P-47 tank capacity approx 300 gals. So 1 Lanc holds gas for 10 P-47's on empty.

Too lazy to figure out fuel burned to get to altitiude but say 50 gals top up would enable refuel of 60 P-47's. Not knowing pump rate but at say 5 minutes cycle time per plane, that would take 2.5 hours to refuel 60 P-47s for 1 Lanc.

 

[evangilder]

500 spitfires just guarding a spot. Seems like a big resource allocation to me.

 

[davebender]

500 spitfires just guarding a spot. Seems like a big resource allocation to me.

Not when you consider the number of Spitfires Britain had by 1943, most of which were doing very little.

 

[pbfoot]

Not when you consider the number of Spitfires Britain had by 1943, most of which were doing very little.

Escorting the the 9th and 8th AF 's was doing nothing, not to mention whittling down some of the better Luftwaffe pilots . Remember some of the better USAAF pilots cut their teeth on those mission flying with RCAF wings on
Blakesee, Gentile, Hofer, Beeson

 

[evangilder]

Not just the 500 Spitfires that you are putting at potential risk, but the pilots too. How much gas are they burning versus what the benefit of it is? Remember that the UK, and the US, were rationing fuel at that time. To burn the gas for 500 fighters and an untold amount of tankers is a big allocation of resources.

 

[FLYBOYJ]

Not only were you looking at massive amounts of tankers having to be built, you had to have refueling probes on all the fighters and bombers = additional weight. Also consider a probe sticking out in the airstream on say a Spitfire. Sure, you could say "how about building a retractable probe" well again, weight + complexity to the situation.

Lastly the greatest challenge that would have been faced is training. Bad enough we saw 2 and 300 hour pilots thrown into combat, these same folks would have had to been trained on aerial refueling. Do you think pilots just go out and hook up to a tanker???? There is a lengthy and complicated part of a modern training syllabus for training pilots to take on fuel and its a lot more complicated than just flying in formation.

 

[Shortround6]

1 Lancaster - 22000 lb bomb capacity equates to about 3000 US gal of gas.

P-47 tank capacity approx 300 gals. So 1 Lanc holds gas for 10 P-47's on empty.

Too lazy to figure out fuel burned to get to altitiude but say 50 gals top up would enable refuel of 60 P-47's. Not knowing pump rate but at say 5 minutes cycle time per plane, that would take 2.5 hours to refuel 60 P-47s for 1 Lanc.

Those max load take-offs were dangerous. An engine failure on take-off is bad enough at normal take-off weights.

Assuming a single tanker could refuel two fighters at once (not unreasonable with probe and drogue) you are still going to need a lot of tankers. Just how much fuel is being burned by the first few fighter to "top off" while waiting for the the 5th-8th pairs of fighters to top off? Assuming 16 fighter per tanker? And how much fuel is burned by the dozen and half tankers needed for 300 fighters?

Using old Stirlings means that the fueling is going to take place at 16,000ft or below which isn't exactly giving the fighters the best start. Better than ground level yes.

 

[Crimea_River]

The logisitics just don't seem to make this viable IMO.

 

[Airframes]

I don't think the whole scenario is viable, or worthwhile.
First, a fleet of tankers would have to be provided, crews tained and provided, airfields dedicated and fuel storage and supply/filling systems installed. Further, the fighters would have to be modified on the production line and/or field modded, and the pilot's trained. Next, routes out to targets would have to be altered to accommodate a 'race track' flight refuelling area, and a seconadary force of fighters provided to cover the flights being re-fuelled. So, apart from the very large increse in resources, land, equipment, aircraft, personnel and training, there would be the added high financial burden, and the required increase in aircraft production, possibly requiring new factories. Whereas , bolting on a couple of drop tanks, which were evntually made from non-strategic, cheap and disposable materials, allowed the fighters to reach the targets, covering the bombers, joining in combat, strafing on the return if possible, and completeing the whole required route with very little, if any, disruption to the daily schedules, or training or manufacturing. The use of drop tanks in the ETO solved the 'problem' of long-range fighter escort, as it did, to an extent, in the PTO, therefore, at the time, there wasn't a requirement over the (relatively) short distances (in the ETO) to provide all the aforementioned aircraft and systems, when a pair of cheap, disposable drop tanks did the job. As engineers say " If it aint broke, why fix it?".

 

[Crimea_River]

 

[davebender]

I have nothing against drop tanks. The problem is availability. In mid 1943 the European war was about 2/3rd over yet heavy bombers were still being slaughtered for lack of long range fighter escort. Stalin was justified in stating the Soviet Union was practically fighting Germany unassisted except for economic help.

 

[evangilder]

If you think the availability of drop tanks was a problem, please re-read the posts by Joe and Terry. That would be a much larger set of problems.

 

[parsifal]

As I recall, it was the Soviets who invested the most in the concept of carrying fighters on large aircraft, which is actually an easier technique. From memory they slung a small fighter under a large six engined aircraft (I believe it was an ANT-3) and released at the time the fighter was needed.

I dont believe these very imaginative experiments, undertaken in the early '30s, amounted to any tangible military benefit. It seems a very complex and impractical solution in the context of WWII.

As for the claim that the allies were doing nothing to bring about the defeat of Germany in 1943, this just fails to stand up to any serious scrutiny. The USSBS estimate that German economic potential was being degraded by about 10% in 1943, the Germans had all but abandoned bomber production as the allied bomber offensives started to take effect, and about 60% of the German fighter wings were recalled home to defend Germany from the air assault. About 14% of Russian armaments were being obtained through Lend Lease, and the effects of raids like Hamburg in July '43, achieved at minimal cost to Bomber command, shook the confidence of the German leadership to its very core. Conversely, the obvious punishment being meted out on German citiews were a tremendous boost to allied spirits, as at last the Germans were receiving what they had so lavishly inflicted on their victims up to that point.

 

[Markus]

The logisitics just don't seem to make this viable IMO.

Yes, it sounds more and more complicated. There would also be little time to put it into practice. Before the Fall of France no one expected Kent to be the closest base for bombers attacking Germany. After that the RAF relied on night attacks and the USAAF still though its bombers did not need a fighter escort. They were proven wrong but not until late summer/autumn 1943. By that time the P-51B was what; six months away?

Not enough time to make it work and starting said work before the war is unlikley by small budgets and the already mentioned wrong assumptions about the nature of the air war.

 

[parsifal]

well I did some further research, and it seems the allies did contemplate air refuelling as a means to attack Japan. I found this on another site, which may be of interest....

Tiger Force air-to-air refuelling
I have often wondered about what was actually planned for the "Tiger Force" RAF Lancasters and haven't really found anything (any references out there ?)

There is a recently published book "History of Air-to-Air Refuelling" (which isn't what it says, but is really a TECHNICAL history of Flight Refuelling Limited).

Here is a summary of what it says about the Tiger Force Lancasters and flight refuelling (there are pages and pages of technical drawings and explanations showing how the system worked) from pages 24 to 34.

Following on from the successful pre-war "looped-hose" system, in 1942 the US Army Air Corps placed an order for a set of tanker and receiver equipment for a B-24 tanker and B-17 receiver aircraft. These conversions were completed and flight trials commenced in April 1943. The B-17's range being "increased to 5,800 miles with full bomb load". It was planned to take off from the Aleutians and land in China. These plans seem to have come to naught because of the time required to convert the aircraft and train crews and the coming of the B-29.

In the "latter part of 1943" there were plans made for the RAF to bomb Japan from bases in Burma. By 1944 it was decided that these were to be Lancasters equipped with the pre-war looped hose system (as were the B-17 and B-24). In January 1944 three different designs had been prepared, the third of which was adopted. In this the hose-drum and equipment was placed towards the front of the aircraft and the fuel supply consisted of two 640 imperial gallon (2,880 litres) tanks in the bomb bay.

50 sets of equipment were ordered for development and training. It was then intended to convert a total of 500 tanker and receiver aircraft to mount the long-range operations.

Originally the force was to be called "The Long-Ranged Force"

The prototype tanker (PB.972) and receiver (ND.648) aircraft had both been successfully flown by November 1944.

Not only were the two bomb bay tanks available, but also the Port and Starboard Inboard wing tanks (580 gallons [2,880 litres] in each)

The average fuel transfer rate was "better than100 imperial gallons (450 litres) per minute".

AND;

"The trials for the Tiger Force operation were carried out with the prototype Lancaster tanker PB.972 and receiver ND.648, using the equipment described, and it proved that refuelling could be carried out at an indicated airspeed of 160 mph at any reasonable altitude, over or in cloud and at night, there being no difficulty in illuminating the receiver's hauling cable.

Then, due to "progress made in the Pacific Theatre" the whole programme of the Tiger Force was cancelled.

-------------------

The book later (page 39) states that post war that it supplied the US with sufficient equipment to convert 92 KB-29M aircraft to tankers and seventy-four B-29s and fifty-seven B-50As to receivers and implies that the 43rd Air Refuelling Squadron used this equipment in achieving their air-refuelled non-stop around-the-world flight between 26th February and 2nd March 1948

 

[FLYBOYJ]

well I did some further research, and it seems the allies did contemplate air refuelling as a means to attack Japan. I found this on another site, which may be of interest....

Tiger Force air-to-air refuelling
I have often wondered about what was actually planned for the "Tiger Force" RAF Lancasters and haven't really found anything (any references out there ?)

There is a recently published book "History of Air-to-Air Refuelling" (which isn't what it says, but is really a TECHNICAL history of Flight Refuelling Limited).

Here is a summary of what it says about the Tiger Force Lancasters and flight refuelling (there are pages and pages of technical drawings and explanations showing how the system worked) from pages 24 to 34.

Following on from the successful pre-war "looped-hose" system, in 1942 the US Army Air Corps placed an order for a set of tanker and receiver equipment for a B-24 tanker and B-17 receiver aircraft. These conversions were completed and flight trials commenced in April 1943. The B-17's range being "increased to 5,800 miles with full bomb load". It was planned to take off from the Aleutians and land in China. These plans seem to have come to naught because of the time required to convert the aircraft and train crews and the coming of the B-29.

In the "latter part of 1943" there were plans made for the RAF to bomb Japan from bases in Burma. By 1944 it was decided that these were to be Lancasters equipped with the pre-war looped hose system (as were the B-17 and B-24). In January 1944 three different designs had been prepared, the third of which was adopted. In this the hose-drum and equipment was placed towards the front of the aircraft and the fuel supply consisted of two 640 imperial gallon (2,880 litres) tanks in the bomb bay.

50 sets of equipment were ordered for development and training. It was then intended to convert a total of 500 tanker and receiver aircraft to mount the long-range operations.

Originally the force was to be called "The Long-Ranged Force"

The prototype tanker (PB.972) and receiver (ND.648) aircraft had both been successfully flown by November 1944.

Not only were the two bomb bay tanks available, but also the Port and Starboard Inboard wing tanks (580 gallons [2,880 litres] in each)

The average fuel transfer rate was "better than100 imperial gallons (450 litres) per minute".

AND;

"The trials for the Tiger Force operation were carried out with the prototype Lancaster tanker PB.972 and receiver ND.648, using the equipment described, and it proved that refuelling could be carried out at an indicated airspeed of 160 mph at any reasonable altitude, over or in cloud and at night, there being no difficulty in illuminating the receiver's hauling cable.

Then, due to "progress made in the Pacific Theatre" the whole programme of the Tiger Force was cancelled.

-------------------

The book later (page 39) states that post war that it supplied the US with sufficient equipment to convert 92 KB-29M aircraft to tankers and seventy-four B-29s and fifty-seven B-50As to receivers and implies that the 43rd Air Refuelling Squadron used this equipment in achieving their air-refuelled non-stop around-the-world flight between 26th February and 2nd March 1948

At a later time it was discovered that the looped hose system was in fact inefficient and a bit difficult to operate although the Soviet adopted it in their development of air to air refueling. The USAF trials prior to the "Lucky Lady II" flight revealed that the refueling process was a lot more difficult than first thought. In using the drogue system, many times the receiving aircraft found itself right in the middle of the tanker's wake. Additionally the tanker pilots were forced to ensure that only small control corrections were made when the hose was caught by the receiving aircraft. Emergency procedures had to be developed and tested as well as operational processes before air to air refueling could be considered a feasible military operation and I would bet dollars to donuts that had the process been rushed during the "Tiger Force" deployment, there would have been numerous accidents. Later when the "boom" was introduced, the operation was made even more difficult because not only did the receiving aircraft have to fly right up to the receiving aircraft and maintain a specified distance, but you have a "boomer" flying the boom to the receiving aircraft. A little turbulence could make this operation a nightmare. As a matter of fact the accident that saw a nuke carrying B-52 crash over Spain in 1966 occurred during a "routine" aerial refueling operation.

>>EDIT<<

After posting this I had a chat with one of our pilots who flew C-5s. he told me you're looking at about 20 hours training in today's world with a good portion of that training done in a simulator. He also mentioned that fighter guys seem to catch on to the process better than guys flying heavies. I do know my boss' daughter just completed this training (she flies E-3s) and she said this was the hardest thing she had to do flying-wise so far in the USAF.

 

[Zipper730]

From what I'm reading the first aerial refueling system that was remotely feasible at that time was Alan Cobham's design: It seemed to be dependent on multiple crew members.