British escort fighter--what might it have been like?

[pbehn]

Again, nice thought but even though the Spitfire IX had the performance, it didn't have the range. The Spitfire was designed around a 500 mile or so range when it was first designed, and in terms of actual combat, never really got much better. Even the Griffon Spitfires only had enough fuel increases to keep the range to about 500 miles on typical combat missions.

So I ask the question: if the RAF wanted it, and by 1942 it was viable, why didn't they pursue it? Again, it almost seems that they didn't think a domestically produced aircraft of that type was viable, either though concept or being able to be built in England, or even if it was thought possible, no one was readily available to make it or design it.

In fairness to Britain, they did have smaller land mass than the US, less raw materials, fewer factories and a smaller population vs say the US. So that was probably part of the issue (industrial infrastructure). Of course, hindsight being 20/20, even in England there were underworked companies or those that were producing designs that weren't picked up (Boulton Paul, Westland, Airspeed, etc), but even those companies were also doing important subcontractor work for the RAF and RN.

It's almost like the Heinkel He-100 thread. It did, in altered form, almost make it into production. But in much modified form, and you'd have to wait for the Junkers Jumo 213 and Daimler-Benz DB603 engines to be produced in quantity That wasn't until 1944, and by then other designs and such took priority over the Heinkel P.1076..

They did, it was called the Spitfire MkIX and then the Mustang Mk III. The Spitfire was used to assist the USA until well into 1944. Mustang MkIIIs (P-51Bs) were assigned to the British before the USA settled on using the P-51Bs as a bomber escort themselves, so one of the jobs Hap Arnold had was to ask the British to use their Mustang IIIs on US raids. It was of course a rhetorical question, but it was done. Having a two stage Merlin available in 1942 doesnt mean you can commence mass raids. As far as I remember there were 6 squadrons of Spitfire Mk IXs operational at Dieppe (Aug 1942) The P-51 B started being produced in mid 1943 but there were only 100 in UK squadron service for big week Feb 1944.

 

[GrauGeist]

MB-3 was too big for the Merlin, which is why (as well as Sabre durability worries) the MB-5 used a Griffon.

But you're looking for a potential early war British built escort fighter.

The MB.3's physical dimensions (wingspan, length) are close to that of a P-51D.

The early Sabre was troublesome, so what alternate engine might work (excluding the Merlin), perhaps a Centaurus or Hercules?

 

[BarnOwlLover]

Compared with a lot of other threads, this one pretty 'straight' IMO

BTW - do you have a firm figure for a combat radius (not range) the British LR escort should be doing? 450, 500, 550, 600 miles, more?

Problem with most range figures is that they don't seem to account for reserve fuel (amount you want to have upon return for "just in case" issues) or allowances for combat time (15 min, 20 min, 30 min, etc).

I know that I've been told basically that the Mustang does fill the bill, and most of the way it does and did factually happen, since it didn't cause undue stress on Britain's logistical system, since they didn't have to build them, had more than adequate performance for the most part, and were there when wanted/need and in numbers. Of course, I'd prefer a fighter that was lighter, even more maneuverable, faster climbing and cannon armed. And, again, I'd probably be pointed to the Mustang family, namely the XP-51F/G and especially the P-51H.

Interestingly, I did read earlier today that for use in the Pacific, the P-51H was being studied for, among other things, the fitting of up to a 100 gallon fuselage tank. Among the reasons was that due to the CG changing on the lightweight Mustangs and the P-51H, even with a full 100 gallon tank the P-51H would handle better than a P-51D with a partially filled 85 gallon tank.

 

[tomo pauk]

Problem with most range figures is that they don't seem to account for reserve fuel (amount you want to have upon return for "just in case" issues) or allowances for combat time (15 min, 20 min, 30 min, etc).

I'm asking about combat radius, not range.

 

[BarnOwlLover]

Again, that's the problem. Everything I've seen about basic aircraft stats only gives range (which I assume is point A to point B). No mention of combat/loiter time, no mention of reserve fuel. All we can do with that is split the range figure in half to get a rough estimate of combat radius, and even that doesn't paint the complete picture. Hence why I do prefer reports and specs that mention (or also mention) endurance.

For instance, the specs I've seen of the A7M note a 2-2.5 hour endurance with up to 30 minutes combat/loiter time.

As far as radius, for example, to get to Berlin from London roughly is about 600 miles at least. Which doesn't count loiter/combat time, or desired reserve fuel

Maybe not directly related to this thread, but I might start a "what if" thread for a fictional country that wants to develop it's own aviation industry/combat aircraft for World War II in addition to supplementing it by foreign imports (chiefly from the US and England). Having thought about that, maybe that's what I should've been doing from the beginning for this kind of stuff.

 

[GrauGeist]

The distance from Pas-de-Calais to London is about 146 miles.
Even though the Bf109E had a max. range of 410 miles, the London area was as far as it could go, engage any enemy and expect to return to France.

 

[tomo pauk]

As far as radius, for example, to get to Berlin from London roughly is about 600 miles at least.

Good, he have a requirement.

Looking at the AHT, P-51B/D needed a tad under 400 US gals (~335 imp gals) to warm-up, take off, climb to 25000 ft, cruise there at ~310 mph TAS, fight at 5 min at WEP and 15 min at mil power, return at ~310 mph TAS, and still to have 30 min reserve. In order to avoid over-taking the bombers, the 'target escort' have had the support of ingress and egress escort packs. We are mostly interested in 'target escort' her, but the shorter ranged support will still be needed.
British will not have the same requirement in 1939-42 (from start of the war until B-17s arrive in good numbers), they will need to escort the bombers at under 20000 ft, and perhaps fight for 15 minutes - all of that makes the task easier. Something not worse than Spitfire I, powered by Merlin X, with total of 150 imp gals + a good drop tank (another 150 imp gals) will do, before Spitfire III arrives so it can do the job from late 1940 on. Guns can remain the 8 .303s.
Fighter before the Spit III could use some nip and tuck, like the low-drag exhausts, fully covered U/C, internal BP glass etc. Spit III might also use the better exhausts, as well as injection carb.

I know that you don't like mentioning of existing fighters, but it is much easier for me to say 'Spitfire' or 'Tempest' than to try making a point around an imagined A/C, good as it might have been.

From second half of 1942, Merlin 60 series as preferred engines, up the fuel to 180 imp gals internal, 170-180 in drop tanks, streamlining no worse than the Spitfire III (bar the intercooler radiator).

 

[Shortround6]

It's almost like the Heinkel He-100 thread. It did, in altered form, almost make it into production. But in much modified form, and you'd have to wait for the Junkers Jumo 213 and Daimler-Benz DB603 engines to be produced in quantity

Trying to drop 2000lb engines into a small airframe like the He 110 is a lot different than trying to drop a 2000lb engine into the Spitfire. The Spitfire is not known for being large but it was huge compared to the He 100.

 

[BarnOwlLover]

What I meant by He-100 revival was this aircraft:

Heinkel He P.1076

Same concepts, but still basically a new aircraft. And it was comparable in size to later Spitfires and the Fw190.

 

[PAT303]

Again, my point of this thread is saying/asking what a British-built escort fighter would've been like.

A Spitfire Mk VIII/IX with 96G front tank, 42G upper 33G lower rear tank, use all the available space in the leading edges for a combined 50G and a 90G dropper. Warm up taxi take off and climb to 20-25 thousand feet over France on the rear upper 42G, switch to 90G dropper and fly as far as you want before dropping leaving 50G leading edge 96G main for combat and fly home with 33G rear in reserve. Your going to cover a lot of Germany with that aircraft but, and it's a big but, you need to get rid of Portal from the Air Ministry and have 2 stage 2 speed Merlins, if that doesn't happen you have what actually did happen, the Spitfire that never reached it's full potential.

 

[PAT303]

I dont know that the British were firm in that belief, throughout 1941 and into 1942 the best Spitfires couldnt compete over France against the best LW fighters so it was impossible to contemplate escorting bombers to Germany.

No Allied aircraft could fly escort missions in '41-42', the Luftwaffe would have caught on quickly and jumped the escorts as soon as they crossed the channel when they were laden with fuel, you would have got a couple of raids in but that's it.

 

[PAT303]

As far as radius, for example, to get to Berlin from London roughly is about 600 miles at least. Which doesn't count loiter/combat time, or desired reserve fuel

The fighter bases were all on the coast, straight line to Berlin was 500 miles give or take.

 

[tomo pauk]

No Allied aircraft could fly escort missions in '41-42', the Luftwaffe would have caught on quickly and jumped the escorts as soon as they crossed the channel when they were laden with fuel, you would have got a couple of raids in but that's it.

They certainly could, but not in the way they did it. They were especially capable once there is an overmatch in numbers from mid-1941 on, since LW left just a part of their fighters' strength west of Ruhr.
RAF, and later USAAF, need to bring hundreds of bombers to bomb German assets (factories, marshalling yards, POL infrastructure, air bases), to be escorted by many hundreds of fighters. That means no option for LW to decline interception of the bombers, and when they join the combat they will do it under 2:1 or worse ratio vs. escort fighters.

Some nip and tuck will be needed for the Spitfire V so it can do 380+ mph, and the Spitfire III was a missed opportunity back in 1940.

 

[Shortround6]

A Spitfire Mk VIII/IX with 96G front tank, 42G upper 33G lower rear tank, use all the available space in the leading edges for a combined 50G and a 90G dropper. Warm up taxi take off and climb to 20-25 thousand feet over France on the rear upper 42G, switch to 90G dropper and fly as far as you want before dropping leaving 50G leading edge 96G main for combat and fly home with 33G rear in reserve. Your going to cover a lot of Germany with that aircraft but, and it's a big but, you need to get rid of Portal from the Air Ministry and have 2 stage 2 speed Merlins, if that doesn't happen you have what actually did happen, the Spitfire that never reached it's full potential.

It would have been simpler to forget the 42G upper and build a 132G dropper.
If you are bounced on the way in the plane is easily converted to combat mode (proper CG) if a bit over weight. (55 Imp is about 400lbs)

You will ALWAYS start, warm up, taxi and take-off on the lower front tank, ALWAYS.
Height at which change over occurs to an alternate tank is whatever safety dictates. Enough to change to a different tank if the new tank doesn't feed or enough to glide back to base/force land? Manual says 2,000ft
Manual does say to run the engine for 1 minute on the drop tank will warming up to check the feed (warm up at 1000-1200rpm so this is going to be under a gallon, may be under a 1/2 gallon)
The return line from the carb (fuel pump is suppling too much fuel in cruise) is piped to the front tank/s. The overflow will slowly refill the front tank on the climb and flight in.

 

[Howard Gibson]

'The British built 20,000 spitfires…'

that was over a 10 year period

Meanwhile, NA built 17,000 P-51's in 4 years


Ditto the Merlin - 'The British made 150,000 hand fitted Merlins'

That was over a 14 year period

Meanwhile, Packard built 55,000 production engineered Merlins with gaskets in 4 years
An interesting aside, you could always tell which plane was fitted with a RR vs a Packard Merlin - there were always drip trays under the RR Merlins

Murica! Masters of production engineering.

The vast bulk of Merlins and Spitfires were built during war, a period of a bit over five years. The Brits did pretty good.

 

[pbehn]

The vast bulk of Merlins and Spitfires were built during war, a period of a bit over five years. The Brits did pretty good.

American mass production doesnt impress me, only slightly better than a dozen British housewives in a cattle shed with chisels and rasps.

 

[GrauGeist]

American mass production doesnt impress me, only slightly better than a dozen British housewives in a cattle shed with chisels and rasps.

The Cobbler Elf Union would like to have a word...

 

[Howard Gibson]

I keep arguing here that long range escort fighter planes require technology superior to that of the enemy. All else being equal, the short range defending fighters will be slightly faster, will have much better acceleration, rate of climb and maneuverability. They can sacrifice a bit of reduced weight, for better armament. The escort fighters will dive more quickly.

In WWII, the Germans failed to issue high octane fuel and two stage superchargers to their front line squadrons, and none of their aircraft had laminar flow wings.

If the British are to convert a Spitfire to a long range fighter, they must assume it will have reduced performance. The Spitfire_IX was about equal to an Fw190 at most altitudes. The long range Spitfire would be inferior at any altitude below 25,000ft. British bombers did not operate above 20,000ft. American bombers operated at altitudes that suited the two stage superchargers used by their fighters.

Yet another issue is that the Spitfires were regarded as interceptors. They required a fast climb rage and a high top speed. Range was not critical. The RAF were responsible for defense. The Spitfires were just about ideal for the job.

Significantly, in 1943, North American and Supermarine upgraded their aircraft. North American added two machine guns, they strengthed their wings, they added a bubble canopy, and they enlarged fuel tanks. The P-51D was slower than the older P-15Bs and Cs, but they had a longer range. The superior allied technology assured that they were effective at long range.

If Supermarine's objective was to increase range, the Griffon_65 was the worst thing they could have done. The Griffon improved acceleration, rate of climb, and top speed. The Luftwaffe were developing fast, high altitude aircraft. In retrospect, we know they failed to deploy them.

When the RAF flew daylight missions with Lancasters, they used Mustangs as escorts.

 

[Shortround6]

A lot of stuff was on a sliding scale,
A British 1940 escort fighter doesn't have take out 109Gs, it has to take out 109Es.
A British 1941 escort fighter doesn't have to take 109Gs either, it does have to figure out how to deal 109F and a handful of 190s (of dubious ability for part of the year)

We also have to decide what the goal is, Smash the Luftwaffe American spring of 1944 style. Or keep bomber and escort fighter losses to an acceptable level, and not actually kill German fighters in large numbers. Not quite the same thing but it is a rather delicate balance. Germans increase their fighters ability only slightly and British losses go up sharply.

And in 1940 what constitutes long range? The British don't have ANY 4 engine bombers or at least no operational squadron. Even with escorts Whitleys are not what is needed in daylight. Without a new bomber you are going to be escorting Wellingtons with Pegasus engines. How far are the long raids going to be? The Ruhr?
even with escorts the Hampden is a lost cause in daylight.
1941 the bomber situating gets a little bit better and You get the Merlin 45 or perhaps the Merlin XX engine. Germans get the 109F-2 the beginning of the year and a bit later the F-4.
Escorts keep the eight .303s for lightness and firing time. 60 round Hispano's run dry to quickly as the Germans found out.
The Germans completed only 124 FW 190A-2s by the end of Dec 1941. Yes the 190 is something of a game changer but it shows up too late for much of 1941.

 

[BarnOwlLover]

IMO ideally, the best fighter is one the can be configured to do both escort and interception, without or at least minimum performance loss. Unfortunately, that didn't really happen until the P-51H, which was late war, saw no use in Europe and was only entering service just prior to the surrender or Japan. The P-51H was noted as being extremely fast and fast climbing (it had a climb rate faster than the later Griffon Spitfires and the Spiteful). A USAAF test did also remark that the aircraft had excellent maneuverability, but no hard numbers or direct comparisons were given.

This does lead to a lot of what ifs as far as the Mustang, namely if it had been built to British engineering standards in the first place (same also applies to other USAAF and USN aircraft).