1000-1200 HP: long range fighter vs. interceptor?

[tomo pauk]

Some ideas, for different time periods:
-before Sept 1939: Merlin III engine, chin radiators, as good prop as historically available, airframe from either Hurricane (but with thinner wing) or from P-36, 150 US gals internally, one 100 US gal tank, 6x LMGs in wings with 400 rpg or 4x Breda 12.7mm with 300 rpg
-Sept 1939 - Sept 1940: Merlin X, leading-edge radiators, fuselage from Spitfire I, wings similar as on Spitfire, 4x Belgian 13.2mm with 400 rpg
-Sept 1940 - Sept 1941: Merlin XX, again LE radiators, airframe based on Spifire III, 4x 13.2mm with 450 rpg

 

[Kevin J]

Some ideas, for different time periods:
-before Sept 1939: Merlin III engine, chin radiators, as good prop as historically available, airframe from either Hurricane (but with thinner wing) or from P-36, 150 US gals internally, one 100 US gal tank, 6x LMGs in wings with 400 rpg or 4x Breda 12.7mm with 300 rpg
-Sept 1939 - Sept 1940: Merlin X, leading-edge radiators, fuselage from Spitfire I, wings similar as on Spitfire, 4x Belgian 13.2mm with 400 rpg
-Sept 1940 - Sept 1941: Merlin XX, again LE radiators, airframe based on Spifire III, 4x 13.2mm with 450 rpg

You've forgotten the old maxim 'no changes to the production line' in times of crisis.

Armstrong Whitworth put a laminar flow wing on a Hurricane post war https://forum.keypublishing.com/filedata/fetch?id=3616885&d=1272136194 but considering that the Tempest with laminar flow wing didn't fly until 1942 then an earlier Hurricane with a laminar flow wing seems a bit unlikely. As for the P-36, I think you'll find that developed into the P-40 and morphed into the P-60 so I think they covered all the angles. The Spitfire, well the Air Ministry considered cancelling it in 1939 because of production difficulties, had problems producing the Mk II before Beaverbrook took over, then built the Mk III but decided to port some of the changes into the Mk Vc to minimise changes on the production line.

So I think that really only leaves us with the Vultee Vanguard with the two stage P&W R-1830 except these engines were in short supply and needed for the Wildcat. Originally the Vanguard was meant for Sweden, then as an advanced trainer for Canada. The USAAF used 50 as emergency fighters but lost 15 in accidents. The remainder were sent to China who tried them out unsuccessfully then put them in storage.

Alternately there is the Miles M20 with its fixed undercarriage and 1280 hp Merlin. Twice the fuel and bullets of the Hurricane. It might have been okay over in S.E.Asia and the Pacific. It had a top speed competitive with the Hayabusa and Reisen, but being made of wood probably didn't have a max dive speed let alone a top speed that would have made it competitive in either the ETO or MTO. No idea how manoeuvrable it was, nor turning circles nor roll rates. The engine was installed as a power egg, so assume a P&W R-1830 radial could have replaced it easily.

 

[Shortround6]

Some ideas, for different time periods:
-before Sept 1939: Merlin III engine, chin radiators, as good prop as historically available, airframe from either Hurricane (but with thinner wing) or from P-36, 150 US gals internally, one 100 US gal tank, 6x LMGs in wings with 400 rpg or 4x Breda 12.7mm with 300 rpg
-Sept 1939 - Sept 1940: Merlin X, leading-edge radiators, fuselage from Spitfire I, wings similar as on Spitfire, 4x Belgian 13.2mm with 400 rpg
-Sept 1940 - Sept 1941: Merlin XX, again LE radiators, airframe based on Spifire III, 4x 13.2mm with 450 rpg

Performance figures are back in post #22

.............................................MK II Spit..............MK II with 40gal tank climb rates.

Altitude-2,000ft...............2,925fpm......................2240fpm
..................5,000ft...............2,925fpm......................2240fpm
................10,000ft...............2,995fpm......................2,240fpm
................15,000ft...............2,770fpm......................1,990fpm
................20,000ft...............2,175fpm......................1,420fpm
................25,000ft...............1,600fpm......................1,050fpm
................30,000ft...................995fpm.........................545fpm

WHile the drop in speed would be solved (mostly) by internal tank/s instead of external the change in rate of climb would still be greatly affected even though not quite to the extent shown here.
2 squadrons were equipped and operated these aircraft, at least for a short period of time. They were disliked due to the loss of performance. They had metal ailerons and roll was not really a problem (but then the majority of Spitfires in service may have had fabric ailerons?)

As for the Belgian 13.2mm guns.
400 rounds of ammo per gun (with no guns) weighs 50% more than the eight .303 gun battery with ammo in the Hurricane and Spitfire.
with guns it is 80kg more than the standard 20mm/.303 fitted to the MK Vc.
Adding 50rpg adds 27-28kg.

The four Breda-Safats with 300rpg are going to be lighter but still over 210kg.

Leading edge radiators on the Spit are going to improve speed but they shift the weight of the radiators and coolant from behind the CG to in front of it. Of course that might help balance the fuel tank behind the pilot?

 

[tomo pauk]

You've forgotten the old maxim 'no changes to the production line' in times of crisis.

Armstrong Whitworth put a laminar flow wing on a Hurricane post war https://forum.keypublishing.com/filedata/fetch?id=3616885&d=1272136194 but considering that the Tempest with laminar flow wing didn't fly until 1942 then an earlier Hurricane with a laminar flow wing seems a bit unlikely. As for the P-36, I think you'll find that developed into the P-40 and morphed into the P-60 so I think they covered all the angles. The Spitfire, well the Air Ministry considered cancelling it in 1939 because of production difficulties, had problems producing the Mk II before Beaverbrook took over, then built the Mk III but decided to port some of the changes into the Mk Vc to minimise changes on the production line..

I'm afraid that Spit V incorporated close to zero improvements from Mk.III, bar for the versions with clipped wings.
Thinner wing Hurricane need to be designed instead of historical Hurricane, there is plenty of theoretical and practical knowledge in UK proper that thinner wings work better already in 1920s. As for the production diffculties, whether real or perceived, let's cut the deadwood that is just about to be produced in late 1930s.
BTW - my proposal is not strictly aimed for RAF, but more of an excercise in using the available 'ingredients' and knowledge of military A/C around the world. For example, Merlin is probably the best bet in late 1930s/early 1940s to make a LR fighter.

 

[Kevin J]

I'm afraid that Spit V incorporated close to zero improvements from Mk.III, bar for the versions with clipped wings.
Thinner wing Hurricane need to be designed instead of historical Hurricane, there is plenty of theoretical and practical knowledge in UK proper that thinner wings work better already in 1920s. As for the production diffculties, whether real or perceived, let's cut the deadwood that is just about to be produced in late 1930s.
BTW - my proposal is not strictly aimed for RAF, but more of an excercise in using the available 'ingredients' and knowledge of military A/C around the world. For example, Merlin is probably the best bet in late 1930s/early 1940s to make a LR fighter.

With the Spitfire Vc, it was minimal changes and keep the production lines producing more and more fighters, with the Hurricane it was get some fighters quickly using tried and trusted construction methods. I agree that the Merlin is the best bet for a long range fighter but something will have to be compromised to get that range. The Miles Kestrel trainer did 297 mph on 745 bhp, so perhaps we need Miles producing the M20 fighter earlier than it did. The compromises, a fixed undercarriage allowing for more space for fuel in the wings and a low dive speed. If you're the escort then you need to stay with the bombers to defend them so is high speed really that essential?

 

[Shortround6]

I'm afraid that Spit V incorporated close to zero improvements from Mk.III, bar for the versions with clipped wings.
Thinner wing Hurricane need to be designed instead of historical Hurricane, there is plenty of theoretical and practical knowledge in UK proper that thinner wings work better already in 1920s. As for the production diffculties, whether real or perceived, let's cut the deadwood that is just about to be produced in late 1930s.
BTW - my proposal is not strictly aimed for RAF, but more of an excercise in using the available 'ingredients' and knowledge of military A/C around the world. For example, Merlin is probably the best bet in late 1930s/early 1940s to make a LR fighter.

The problem with the "thinner wings work better already in 1920s." is that very thin wings had been used on Biplanes even in WW 1.

Unfortunately many of the thin wings, while low in drag, were also low in lift per sq ft and had vicious stall characteristics. Which is why Handley Page and Lachmann (came up with his initial idea in a hospital bed after a stall related crash) developed leading edge slats/slots. Nobody was really flying that fast in the 1920s except for a few racers and most race planes were very difficult to fly. Small wings, high torque in some cases vestigial vertical stabilizer and rudders. Basically accidents waiting to happen.
The thicker wings offered more lift per sq ft, stronger structure for the same weight (especially after the biplanes started to go away) and sometimes ( but not always) a gentler stall or at least not so abrupt which meant that slats (and royalties to HP and Co.) could be avoided.

Since the Merlin is the best bet that means any country without the Merlin was really up the creek without a paddle and explains the some of the weird and wonderful twin engine planes that tried (unsuccessfully) to fill the long range escort role.

 

[Kevin J]

According to the thread
Questions about the VG-33 and Miles M.20

the Miles M20 was more manoeuvrable than the Hurricane and was test dived at 450 mph; range is twice that of a Hurricane, speed is the same.
It looks perfectly adequate to me as a long range escort especially in the Far East and the Pacific at least up until about 1944, in the ETO, I imagine it would have struggled a bit after the Bf 109F was introduced but who knows as I don't think it was pitted against a Bf 109F in testing. Certainly its speed was comparable to the early Yak-1's and they seemed to survive better that than any other Soviet aircraft in 1941. As for the Spitfire Vb in the 1941 Channel Air Offensive, it seems to me that they got shot from the skies, so would an M20 have been any worse?

 

[Timppa]

Some ideas, for different time periods:

I would guess that the reasonable combat radius for escort fighters starts from about 500 miles.

 

[Kevin J]

I would guess that the reasonable combat radius for escort fighters starts from about 500 miles.

I'd disagree here, certainly in the opening phases of the daylight air war in the ETO, we should be looking at about 450/500 miles max i.e. how far the Blenheim could go on a mission. A miles M20 with two 90 gal drop tanks would have been able to escort Blenheims on those long range missions where they got shot from the skies.

 

[Shortround6]

the Miles M20 was more manoeuvrable than the Hurricane and was test dived at 450 mph; range is twice that of a Hurricane, speed is the same.

this claim, often repeated, seems a bit dubious or they were comparing the Miles M. 20 to a Hurricane I with a Merlin III

.
M.20/4)......................................................Hurricane IIA

• Crew: one pilot.............................................................................one pilot
• Length: 30 ft 8 in (9.35 m)......................................................31ft 5inft
• Wingspan: 34 ft 7 in (10.54 m).............................................40 ft
• Height: 12 ft 6 in (3.81 m).......................................................10ft 6in
• Wing area: 234 ft² (21.74 m²)................................................258 sq ft
• Empty weight: 5,908 lb (2,685 kg)......................................5,559 lb*
• Max. takeoff weight: 8,000 lb (3,629 kg).........................7,397 lb*/***
• Powerplant: 1 × Rolls-Royce Merlin XX V12 inline engine, 1,260 hp (940 kW)

Performance

• Maximum speed: 333 mph (290 knots, 536 km/h),,,,,,,,,,326mph*
• Range: 920 mi (800 nmi, 1,481 km)......................................... 500 mi. **
• Service ceiling: 32,800 ft (10,000 m)........................................35,900 ft*
• Climb to 20,000 ft (6,100 m): 9 min 36 s.............................8 min 30 s*

* weights , speed. ceiling and climb to 20,000ft are for a Hurricane IIB with twelve guns.
** range is from the Data card for the II a with eight guns.
Please note the speed on the data card for the IIa was 342mph but as we all know the speeds varied somewhat from plane to plane and please note the IIb was somewhat used aircraft having been used for trials concerning underwing fuel tanks before being converted back to standard for the performance trials. Its finish may not have been of the highest standard?
*** a Hurricane IIa with eight guns used to finish the handling trials weighed 6558lbs as tested.

Edit: from the Hurricane IIa data card the service ceiling was 37,000 ft and the climb to 20,000ft was 8.2 minutes.

 

[Shortround6]

I'd disagree here, certainly in the opening phases of the daylight air war in the ETO, we should be looking at about 450/500 miles max i.e. how far the Blenheim could go on a mission. A miles M20 with two 90 gal drop tanks would have been able to escort Blenheims on those long range missions where they got shot from the skies.

See above.

The Blenheim is a weird case. The MK I was good for about 1000 miles of range or about 400 miles radius (take one hour out of the range for "reserve" and allowances (forming up, climb etc) The MK IV got extra fuel tanks in the outer wings and was good for about 1400 miles of range (at most economical) so 500 to 600 mile radius?

I am not at all sure the M.20 should have been trying to play long range escort. Knocking 250lbs of the weight of the M-20 as given (100lbs of fuel and 150lbs of ammo/300rounds per gun) you get a wing loading of about 33.1lb sq/ft compared to the 12 gun Hurricanes 28.7 lb/sq/ft. Wing loading isn't everything but the Hurricane has 87% of the wing loading not 3-5% difference. The Hurricane is hundreds of pounds lighter using the same engine. The Hurricane climbs 13% quicker to 20,000ft.
If the Hurricane can't escort the bombers at short range why do we think the M.20 is going to work at long range?

 

[Kevin J]

this claim, often repeated, seems a bit dubious or they were comparing the Miles M. 20 to a Hurricane I with a Merlin III

.
M.20/4)......................................................Hurricane IIA

• Crew: one pilot.............................................................................one pilot
• Length: 30 ft 8 in (9.35 m)......................................................31ft 5inft
• Wingspan: 34 ft 7 in (10.54 m).............................................40 ft
• Height: 12 ft 6 in (3.81 m).......................................................10ft 6in
• Wing area: 234 ft² (21.74 m²)................................................258 sq ft
• Empty weight: 5,908 lb (2,685 kg)......................................5,559 lb*
• Max. takeoff weight: 8,000 lb (3,629 kg).........................7,397 lb*/***
• Powerplant: 1 × Rolls-Royce Merlin XX V12 inline engine, 1,260 hp (940 kW)

Performance

• Maximum speed: 333 mph (290 knots, 536 km/h),,,,,,,,,,326mph*
• Range: 920 mi (800 nmi, 1,481 km)......................................... 500 mi. **
• Service ceiling: 32,800 ft (10,000 m)........................................35,900 ft*
• Climb to 20,000 ft (6,100 m): 9 min 36 s.............................8 min 30 s*

* weights , speed. ceiling and climb to 20,000ft are for a Hurricane IIB with twelve guns.
** range is from the Data card for the II a with eight guns.
Please note the speed on the data card for the IIa was 342mph but as we all know the speeds varied somewhat from plane to plane and please note the IIb was somewhat used aircraft having been used for trials concerning underwing fuel tanks before being converted back to standard for the performance trials. Its finish may not have been of the highest standard?
*** a Hurricane IIa with eight guns used to finish the handling trials weighed 6558lbs as tested.

I think it depends on what is meant by manoeuvrability. It did have shorter wings than the Hurricane and the same sort of weight, so maybe we're talking about roll rate here as the Spitfire's rate of roll improved with clipped wings. Dive speed was definitely better, 450 as opposed to 410 mph.

 

[Kevin J]

See above.

The Blenheim is a weird case. The MK I was good for about 1000 miles of range or about 400 miles radius (take one hour out of the range for "reserve" and allowances (forming up, climb etc) The MK IV got extra fuel tanks in the outer wings and was good for about 1400 miles of range (at most economical) so 500 to 600 mile radius?

I am not at all sure the M.20 should have been trying to play long range escort. Knocking 250lbs of the weight of the M-20 as given (100lbs of fuel and 150lbs of ammo/300rounds per gun) you get a wing loading of about 33.1lb sq/ft compared to the 12 gun Hurricanes 28.7 lb/sq/ft. Wing loading isn't everything but the Hurricane has 87% of the wing loading not 3-5% difference. The Hurricane is hundreds of pounds lighter using the same engine. The Hurricane climbs 13% quicker to 20,000ft.
If the Hurricane can't escort the bombers at short range why do we think the M.20 is going to work at long range?

The point is that it has double the range on internal fuel as the Hurricane, so it could take twice the drop tank size. I think you'll find that the longest Blenheim missions were at about 450 to 500 miles and usually they were suicide missions as no escort was available. The Miles M20 available earlier would have been a great help.

 

[Shortround6]

The point is that it has double the range on internal fuel as the Hurricane, so it could take twice the drop tank size. I think you'll find that the longest Blenheim missions were at about 450 to 500 miles and usually they were suicide missions as no escort was available. The Miles M20 available earlier would have been a great help.

That is not quite how it works. You do have to get the plane off the ground and into the air with the desired fuel load.
180 imperial gallons (two 90 gallon drop tanks) weighs 1350lbs not including weight of the tanks and any racks/fittings needed.
think the later 90imp/108 us gallon tanks.

You don't have to double the internal fuel load to get a significant increase in radius. climbing to operational height took a lot of fuel for the US fighters trying to escort turbocharged bombers but the British bombers, especially the early ones didn't fly anywhere near that high.
The Blenheim was a lousy bomber to conduct long range bomber missions with as the bomb load was just a bit above the nuisance level.
M.20s provind escort might have save some but you are going to lose a bunch of M.20s and the tonnage of bombs delivered just wasn't worth it.
A Hampden could easily deliver about 4 times the bomb load over most ranges as could the Pegasus powered Wellingtons.

The Blenheim crews were brave men who were sacrificed by higher command to no good purpose but providing M.20 escorts may not have changed the situation much.

 

[Kevin J]

That is not quite how it works. You do have to get the plane off the ground and into the air with the desired fuel load.
180 imperial gallons (two 90 gallon drop tanks) weighs 1350lbs not including weight of the tanks and any racks/fittings needed.
think the later 90imp/108 us gallon tanks.

You don't have to double the internal fuel load to get a significant increase in radius. climbing to operational height took a lot of fuel for the US fighters trying to escort turbocharged bombers but the British bombers, especially the early ones didn't fly anywhere near that high.
The Blenheim was a lousy bomber to conduct long range bomber missions with as the bomb load was just a bit above the nuisance level.
M.20s provind escort might have save some but you are going to lose a bunch of M.20s and the tonnage of bombs delivered just wasn't worth it.
A Hampden could easily deliver about 4 times the bomb load over most ranges as could the Pegasus powered Wellingtons.

The Blenheim crews were brave men who were sacrificed by higher command to no good purpose but providing M.20 escorts may not have changed the situation much.

I'm sure that M20 escorts would have helped save a lot of Blenheim crews lives, but I think that's the only use for an M20. As soon as the Blenheim goes, the M20 goes. The Hampden just had too long a range to be escorted over; the solution to the Hampden's vulnerability problem was to replace it with the Mosquito. As for the Wellington and Whitley, I'm sure that they were best employed as night bombers. Its like the Fairey Battle problem, the solution is in fact the Il-2.

 

[Shortround6]

Its like the Fairey Battle problem, the solution is in fact the Il-2

The Fairey Battle problem was multi-faceted.
It started by trying to use a not very good strategic bomber (1000 mile range for a tactical bomber?) for tactical duties ( only a few other single engine "bombers" used a bombardier with a bombsight. In part because the tactical aircraft tasked by the RAF for tactical support were even worse (Westland Lysander). Which means the crews didn't have a lot of training, the planes may have been ill equipped (no low altitude bomb sight?) nad combined training with escorting fighters had rarely, if ever been done and the escorting fighters often were based out of different airfields so just joining up was major problem.
Operating in a role it was not intended for, by crews who had only rudimentary training in the that role ( yes , they may have made some practice dives or a few low altitude bomb runs in training) in the face of the best AA defence in Europe at the time (let alone the Luftwaffe) by a high command who didn't yet understand timing or co-ordination the whole thing was doomed to failure.
You could have given the British crews 1942 IL-2s in 1940 in France and the results wouldn't have been much different.

 

[Shortround6]

I take it by disagreeing with me you Believe IL-2, operating without fighter escort, could have destroyed the German Bridges over the Muse and other targets in France in 1940 without catastrophic losses?

 

[Kevin J]

I take it by disagreeing with me you Believe IL-2, operating without fighter escort, could have destroyed the German Bridges over the Muse and other targets in France in 1940 without catastrophic losses?

Not at all. The Yak-1 was designed as an escort fighter for the Il-2. You need both, a short range escort fighter and a heavily armed assault aircraft.

 

[The Basket]

Any bomber of the 1930s like the Battle or the Blenheim is going to struggle in 1940. Blenheim in 1934 was super dooper so I have to say that it was perfectly adequate for its time.

 

[Kevin J]

Any bomber of the 1930s like the Battle or the Blenheim is going to struggle in 1940. Blenheim in 1934 was super dooper so I have to say that it was perfectly adequate for its time.