Bomber escort logistics?

[nincomp]

What were the logistics of fighter relays that escorted bombers?

First of all, when did allied bombers start getting fighter escorts in the ETO?

The first leg is easy, but it is the other legs that I wonder about. For example, did the fighters simply fly from airbases closer to the bombing target? Where were these airbases when the escorting missions started?

In another thread, someone suggested the possibility of fighters escorting fighters. In this case, one set of fighters flew top-cover at "battle ready" speed, protecting the long-range fighters. The long-range might carry additional drop tanks, and/or fly at a relatively low cruise speed to conserve fuel for their leg of the bomber escort.

I am open to the possibility that the real answer is obvious, and I just do not see it.

Thanks,

 

[davebender]

If your fighter aircraft have adequate range and loiter time then you don't need as many. In any case you must have enough escort fighters with the bombers at all times to form a loose protective umbrella above them. Too few fighter escorts and they have no choice but to fly close escort.

 

[tyrodtom]

No one group of fighters stayed with the bombers all the way to and from the target.
One group might escort half way to the target, then they're replaced by another group. Which is then replaced by another, and so on.

You may have 1000 fighters escorting the bombers total, but only 200 fighters with them at any one time. That was why it was such a catastrophe if one of the scheduled rendevous of the escorting fighters were late, or navigated so far off they couldn't find the bombers.
And the fighters zig-zaged over the flight path of the bombers, that way they could stay at their higher cruise speed, and not outpace the bombers, but still be closer to their own combat speed.

 

[nincomp]

No one group of fighters stayed with the bombers all the way to and from the target.
One group might escort half way to the target, then they're replaced by another group. Which is then replaced by another, and so on.

You may have 1000 fighters escorting the bombers total, but only 200 fighters with them at any one time. -

And the fighters zig-zaged over the flight path of the bombers, that way they could stay at their higher cruise speed, and not outpace the bombers, but still be closer to their own combat speed.

Thanks,
I guess that I am still confused about where the later fighter relays were based in order for them to have enough fuel to stay with the bombers near the target.
Since the escorting fighters stayed at combat speed by performing S-turns above the bombers, they would, of course, burn more fuel than another group of similar fighters flying at their most economical cruise speed.

Did the second and later relays fly slower to the hand-off point in order to conserve fuel, or did they come from a base closer to the target?
If one set of fighters flew slower and/or had additional drop tanks, it would be logical for them to need the same kind of zig-zagging escorts as the bombers. It seems logical to me, but that does not mean that it actually happened, of course.

 

[GregP]

This will be interesting and poke holes in the Hellcat in Europe naysayers. Yep, they cruised at economy settings and didn't fly over known flak locations or known figher opposition or heavily-defended targets at lower altitudes. It will work for numerous types, not just the ones who did it.

If you takeoff, climb to altitude at rather lazy rates, and cruise at lean economy settings, you can conserve a lot of fuel, which is why I think other types could also have done it. The types they used weren't much longer-ranged than proposed types in the "what if." The P-51 was a game changer because of its unrefueled range, but suffered from longitudinal instability when loaded past the aft CG limit (naturally!) as it was when all the starting fuel was aboard the aircraft including normal internal fuel, the fuselage tank, and the two drop tanks. Yes, the P-51 could DO it, but the plane wasn't exactly happy about it and would bite if mistreated, as will ANY aircraft past the aft CG limit.

They would takeoff on mains, switch to fuselage, burn that down until stablity returned, then switch to drop tanks until empty or attacked. Then jettison, fight ... and continue. If the Germans ever knew how unmaneuverable the P-51's were when full of fuel plus drop tanks, the main fighter opposition probably would have been as near to the P-51 airfield as they could get in order to attack when the P-51's were at a serious disadvantage. They never really knew and seemingly never tried for the same strategem themselves.

But their leadership was seemingly more interested in stealing priceless works of art in France than beating RAF Fighter Command ... maybe they just liked the food ...

 

[Shortround6]

Thanks,
I guess that I am still confused about where the later fighter relays were based in order for them to have enough fuel to stay with the bombers near the target.
Since the escorting fighters stayed at combat speed by performing S-turns above the bombers, they would, of course, burn more fuel than another group of similar fighters flying at their most economical cruise speed.

Did the second and later relays fly slower to the hand-off point in order to conserve fuel, or did they come from a base closer to the target?
If one set of fighters flew slower and/or had additional drop tanks, it would be logical for them to need the same kind of zig-zagging escorts as the bombers. It seems logical to me, but that does not mean that it actually happened, of course.

Drgondog knows a lot more about this but I don't believe they ever bothered to use fighters to escort other fighters with large drop tanks.

There seems to be lot of talk about "cruising speeds".

Please note that EVERY SPEED on this chart is a "Cruising speed". So you could cruise an early P-47 at 300mph at 12,000ft burning 160 gallons an hour and fly 450 miles OR you fly at about 220-225mph ( there is a difference between true airspeed and indicated airspeed) at 12,000ft and burn 65 gallons an hour and fly 880 miles on the same fuel. Or pick speeds in between or at different altitudes.

Second and later relays could fly slower up to a point, they also took off later. Escorts for the homeward legs might take-off a number of hours after the bombers and initial escorts took off.

 

[davebender]

as near to the P-51 airfield as they could get in order to attack when the P-51's were at a serious disadvantage.

P-51s didn't arrive until spring 1944 and P-51D didn't arrive until summer 1944.

By summer 1944 1st and 2nd SS Panzer Korps were holding by their fingernails just south of Caen and Army Group Center was fighting for it's life (and losing) in Belarus. Under such circumstances sending intruder missions over England or English Channel was a low priority. Small scale intruder operations over England April to June 1944 came to a screeching halt after June 1944.

Perhaps things would have been different if P-51 bomber escorts had shown up a year sooner.

 

[tomo pauk]

Locating LW fighters close to the P-51 bases would've been a major boon to the Allies. Here they can bring to the table Spitfires, Typhoons, Tempests, P-47s, along with decent number of the 2-engined bombers and wreak havoc with LW fighters. That would make the fighter opposition (vs. USAF) above Germany a non-issue, too.
The P-51B was a major player during the Big Week (February 20–25, 1944), the 73 P-51s taking part in it during the 1st day, only one lost in combat, claiming 37 LW planes. The initial operations in ETO were conducted in Dec 1943/Jan 1944. So it was still the winter when the P-51 made it's mark.

 

[syscom3]

P-51s didn't arrive until spring 1944 and P-51D didn't arrive until summer 1944.

P51's began operations in Dec 1943 (in addition to a single P38 group). By the end of Feb 1944, there were four P51 groups and two P38 groups. By the end of March 1944, there were three P38 groups and five P51 groups.

Perhaps things would have been different if P-51 bomber escorts had shown up a year sooner.

The same could be said about the P38's being operational in the summer of 1943.

 

[tomo pauk]

I'd like to state that LW was ill able to do much about, in case the Allies introduced a 500 mile fighter during the summer of 1943. LW needed fighters to cover the preparation, execution and retreat from Battle of Kursk, while already being greatly outnumbered vs. Allies during the invasion of Sicily and, later Italy. The pressure in the ETO was growing every day, too, the absence of long-range fighter sweeps escorts giving the LW the much needed breathing space.

 

[drgondog]

P-51s didn't arrive until spring 1944 and P-51D didn't arrive until summer 1944.

354th FG operational in ETO with Full compliment of P-51Bs in November 1943 and flew first combat mission under leadership of Lt,Col Blakeslee, the Gp Ops of 4th FG on December 1 to Knocke area.

If one specifies 'spring' 1944 as sometime on or after March 31, 1944, then the Combat debut was nearly four months before your reference time.

By summer 1944 1st and 2nd SS Panzer Korps were holding by their fingernails just south of Caen and Army Group Center was fighting for it's life (and losing) in Belarus. Under such circumstances sending intruder missions over England or English Channel was a low priority. Small scale intruder operations over England April to June 1944 came to a screeching halt after June 1944.

Perhaps things would have been different if P-51 bomber escorts had shown up a year sooner.

????

 

[davebender]

RAF probably had more Mustangs then that operating over France and Norway. Not to mention hundreds of Spitfires participating in Circus raids on a regular basis. American P-51s would not get anyones attention until they starting showing up over places such as Berlin and Polesti.

 

[drgondog]

This will be interesting and poke holes in the Hellcat in Europe naysayers. Yep, they cruised at economy settings and didn't fly over known flak locations or known figher opposition or heavily-defended targets at lower altitudes. It will work for numerous types, not just the ones who did it.

Between assembly and climb to altitude, the settings were fast cruise to R/V point..consistent with a.) extending total range, and b. Catching up to their assigned bomber wing somewhere in Germany for the deep Penetration/Target escort/Withdrawal leg. Essing with tanks was around 280mph TAS at 26,000+ while maintaining pace of 200mph TAS bombers until leaving escort or engaging in a fight.

In the case of your F6F, the cruise speed for maximum range was around 200mph at 12K - which meant that the F6F could a.) not catch up and b.) be 12-14000 feet under the bombers. To operate as escort they would have to adopt non optimal cruise/fuel consumption just to climb and cruise fast enough to escort B-17s at 28,000 feet escort altitude.

Yes Bomber routes and waypoints emphasized avoidance of major city/flak concentrations - but ignore known fighter bases.

If you takeoff, climb to altitude at rather lazy rates, and cruise at lean economy settings, you can conserve a lot of fuel, which is why I think other types could also have done it.

Every escort fighter had different bandwidths for best cruise at 22-26000 feet, but the P-47, P-38 and P-51 all HAD to cruise from 280 to 320 inbound to get to a R/V point. One of the primary reasons was that the Fighters ALWAYs took off and formed up at least an hour after the heavies cleared the airspace over East Anglia - too many airplanes in the air... so the B-17s were 200 miles away before the fighters got to work.

The 'problem' for the F6F in contrast to the P-47 was that the F6F cruised best at 200 mph at 12000 feet - which means 'it never gets where it needs to be'. It's fuel economy at best case was worse than the P-47D2 through -23 and even worse, had 55 fewer gallons internally as well as less fuel externally.

Still, you flail away that the F6F-3 could exceed the operational range of a better performing fighter (P-47) that couldn't be assigned target escort to Brunswick until summer 44..

The types they used weren't much longer-ranged than proposed types in the "what if." The P-51 was a game changer because of its unrefueled range, but suffered from longitudinal instability when loaded past the aft CG limit (naturally!) as it was when all the starting fuel was aboard the aircraft including normal internal fuel, the fuselage tank, and the two drop tanks. Yes, the P-51 could DO it, but the plane wasn't exactly happy about it and would bite if mistreated, as will ANY aircraft past the aft CG limit.

SOP - burn 25-60 gallons from fuse tank (depending on length of escort) during formation assembly, climb and cruise toward R/V, then switch to externals. No problem. At that point, the P-51 has ~230-245 gallons internally plus 220 externally, has a much faster cruise per gallon of fuel, uses much less fuel per mile.

Net - Mustang has more internal fuel remaining, cruises faster, better GPM, much more external fuel than the F6F-3 at every point in the flight profile - but it has LESS internal fuel than the P-47D while operating on external fuel... and still the Jug can't escort past Brunswick. But YOU think 'positively' and 'out of the box' and somehow squeeze magic dust into the F6F to get it to Berlin?

Tell us again how your cruise settings work at 26,000 feet?

They would takeoff on mains, switch to fuselage, burn that down until stablity returned, then switch to drop tanks until empty or attacked. Then jettison, fight ... and continue. If the Germans ever knew how unmaneuverable the P-51's were when full of fuel plus drop tanks, the main fighter opposition probably would have been as near to the P-51 airfield as they could get in order to attack when the P-51's were at a serious disadvantage. They never really knew and seemingly never tried for the same strategem themselves.

Greg - the LW would have a real hard time attacking Britain during fighter take offs.. while the Mustang wasn't numerically overwhelming over Germany, the 8th and 9th AF P-47s were up and moving toward penetration escort and RAF wasn't taking a nap. Bodenplatte didn't work out well when they had advantage of complete surprise - away from UK on a much smaller force - with huge numerical advantage for LW. And you are talking about 20-30 minutes of aft cg from takeoff? You're Galland - how do you a.) gather intel for TO time, b.) gather intel for base to attack for that specific TO time?, c.) get your attacking force past the radar and early defense from RAF?

Oh, I forgot - you've figured out how to make F6F-3 escort to berlin, Posnan, Munich, Brux - and get all your planes back to UK. guess the attack strategy would be simple for you.

But their leadership was seemingly more interested in stealing priceless works of art in France than beating RAF Fighter Command ... maybe they just liked the food ...

Maybe in the case you just cited, they weren't as smart as you and couldn't figure out how to beat RAF screen to catch P-51s in most vulnerable time (and correct place)?

 

[Airframes]

RAF Mustangs at that time were the Mk1, Mk1A, and MkII - Allison engined, and used in Army Cooperation squadrons or Photo Recce, not as fighters or escorts.

 

[drgondog]

Thanks,
I guess that I am still confused about where the later fighter relays were based in order for them to have enough fuel to stay with the bombers near the target.

All 8th and 9th AF Fighter Bases were north of London in East Anglia. Most P-47 bases were closer to Channel because of range limitations.

Since the escorting fighters stayed at combat speed by performing S-turns above the bombers, they would, of course, burn more fuel than another group of similar fighters flying at their most economical cruise speed.

8th/9th AF escort doctrine called for Penetration, then Target Escort, then Withdrawl forces acting in relays to escort bombers inbound to an R/V point, then from R/V to target to R/V for the Target Escort, then R/V back to Holland/French Coast areas where the escorts would leave the bombers to return home


Did the second and later relays fly slower to the hand-off point in order to conserve fuel, or did they come from a base closer to the target?

No. All segments flew at fast cruise to their Bomber R/V point, then throttled back a little while Essing - but still significantly higher cruise speed than the bombers they were escorting, then back to economical high speed cruise from R/V until let down over the Channel.

A Mustang max economy/longest range cruise with 110 gallon drop tanks was about 280-290mph TAS at 25000 feet, increasing as fuel burned and a/c lightened up. When drop tanks were punched the cruise speed went up to approximatel 330-340 mph TAS

If one set of fighters flew slower and/or had additional drop tanks, it would be logical for them to need the same kind of zig-zagging escorts as the bombers. It seems logical to me, but that does not mean that it actually happened, of course.

Bombers didn't 'zig zag'. Nobody enjoyed keeping up in the turns and truly hated mid air collisions. The primary reason for Essing over the bombers was two fold. One to maximize coverage laterally over the bomber stream, and two to provide defensive cover. Escorts flew in two flight sections with one flight trailing and above the other to keep leader free of 6 o'clock bounce. One section crosses over toward the right side while the section crosses back to the left.

The bomber boxes of up to two BG's had a couple mile separation bewteen the leading box ahead, and the trailing box behind.

If a Mustang FG was covering 3 boxes over 15-20 miles, one Squadron would be out in front or high front of the leading box, one squadron would be in trail above the last box and one would be high center. Variations might include one squadron sweeping from front to back 5-10 miles off to one side, with one out in front and one high toward the rear box... and other variations

 

[drgondog]

RAF Mustangs at that time were the Mk1, Mk1A, and MkII - Allison engined, and used in Army Cooperation squadrons or Photo Recce, not as fighters or escorts.

Terry - I have seen reference to RAF mark III's providing escort to some max effort 8th AF missions. IIRC none of the Mk III's prior to May 1944 had any internal fuselage tanks but I know that on April 24, 1944 Munich raid, some provided Withdrawal from Hildesheim back past Frankfort before being relived by P-47's

 

[Airframes]

Yes Bill, you are correct. I was referring to the period between end of 1943 and March 1944. And yes, the fuselage tanks were a retro-fit, from around May '44 on, although some aircraft continued without them.

 

[davebender]

Don't think that's the problem.

In the real world you don't get the benefit of hindsight with complete access to friendly and enemy historical records. Determining effectiveness of newly introduced enemy equipment and tactics is little more then guesswork. You don't even know effectiveness of your own newly introduced weapons for a few months.

With the benefit of hindsight major nations such as Germany, Britain, France and USA would have nukes by 1939. They'd all be very polite to each other or else Europe (including Britain) gets blown off the map.

 

[nincomp]

Bombers didn't 'zig zag'. Nobody enjoyed keeping up in the turns and truly hated mid air collisions. The primary reason for Essing over the bombers was two fold. One to maximize coverage laterally over the bomber stream, and two to provide defensive cover.

I did not mean to imply that bombers zigged or zagged. They were already going slower than the fighter cover.

It seems odd to me that even during the time when the range of the fighters was insufficient to escort the bombers all the way to the target, the fighters still burned up extra fuel to travel at a relatively fast cruise.

I am more familiar with the P-38 than with the other fighters. The information that I have seen for the P-38 is that its maximum range was at about 185 MPH with the engines turning at 1600 RPM (at what altitude, I do not know). In this case, it would seem that to maximize escort distance, the fighters for the longer escort legs would lumber along at a low speed to save fuel until needed to climb and speed up to assume their escort duties.
Of course the low and slow portion of the flight would need to be where there was little or no chance of being bounced by enemy fighters or being hit by flak. If enemy fighters could attack all the way along the planned route, it would make sense for the fighters to fly faster and at higher altitude.

I find it surprising that Mustangs would have their maximum range at such a high speed. At the moment, I can think of only a few reasons that this would be so:
-The merlins unable to run well at low RPM
- the propeller is unable to operate at the required steep pitch
- some strange artifact of the mechanical superchargers
- the wing is not efficient at the lower speed

 

[Shortround6]

It is not any of the first 3 and even the 4th isn't right.

It isn't that P-51 has it's maximum range at high speed. It doesn't. It is just that it is low enough in drag that it CAN cruise at those speeds AND cover the required distance with the available fuel.

From Zeno's

Note the last column. 232mph at 5,000ft at 1600rpm and 28.5lbs manifold pressure while burning 42 gallons and hour. Close to the same speed and height as an Early P-47 and both can cover about 880 miles except the P-51 requires about 100 gallons less fuel. Or to put it another way the P-51 can fly 80-90 faster than the P-47 using the same amount of fuel per hour at 25,000ft and over 300mph.

It can take plane several minutes to go from a low cruise (200mph or under) to top speed and if "bounced" at such a low speed it is at a very large disadvantage. It is at a very large disadvantage even with 15-20 seconds warning.