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RAF does not order the Whitley here, but a 4-engined bomber instead of it.
Okay, 3 people didn't exactly liked my idea of foxing the Germans, so I'd forget it - A-W makes a proper 4-engined bomber instead.
Bomb bays were all around the map for not only British bombers, curiously enough the bomber with most generous wing cells was the one with greatest payload - the Whitley. With advent of Whitley and Wellington, bomb bays/cells and payloads of British bombers were a big step ahead of any European or Japanese bombers. Going for a big bomber will just reinforce this.
Weight of the bomber might or might not be a problem on anything that is not tarmac, but ground pressure needs to be kept in check - IOW, heavier bomber will need bigger wheels or more of them, when compared with a lighter bomber.
As for the take-off strips, Wellington I, Hampden*, Manchester and 1st Halifax used 1300-1400 yds, Wellington III under 1100 yds, Whitley with Merlin just 1000 - the big, thick and 'tilted' wing has it's advantages. No british bomber used much of a high-lift devices that help with take offs, like the Fowler flaps, or even something like the 'Junkers flaps', so there is opportunity for improvement.
A fair amount of the bomb load was to be 500lb bombs carried in wing cells to leave a large part of the fuselage (and the CG) free to accommodate the turrets.
That is what they used, not what they were designed for. Or they didn't meet the original specification in that regard.
Blenheim I...... 700 yrds take off at 12,500lbs to 50 ft. 685 yds landing from 50 ft at light weight, (9400lbs?)
Blenheim V.....950 yrds take off at 17,000lbs to 50 ft. 800 yds landing from 50 ft at light weight, (12,000lbs?)
extreme example?
If we are allowed to "design" a plane that was allowed an extra 35% of take off distance and an extra 16-17% of landing distance than the historical planes were designed to meet then I am sure we would wind up with something different.
High lift
devices were being introduced at a rather fast pace. Early flaps, like Gladiator, Hurricane, Spitfire and some American planes were used to steepen the approach and shorten the ground run (reduce landing distance from 50 ft) not to get the plane off the ground. They were NOT lift devices. First production plane to use Fowler flaps flew in prototype form in July of 1937, But you can't add Fowler flaps to an existing wing. you have to design the wing from the start to use them. Any plane that was even 1/2 completed (even just in drawings) was probably far too late to throw out the wing and start over without delaying the whole project by months. And British planes were tending to run late (too long in design and development ) to begin with.
The crappy propellers would have been an easier fix, assuming the British could increase production, to improve take-off performance on the early machines.
1937 to 1942 covers the period of introduction of the Fowler Flap to the double slotted Fowler Flap. The B-17 used a simple split flap and it was rarely, if ever, used for take-off.
Not that the B-17 is a gold standard for advanced aeronautics in WW II but to put in context that many of the British large bombers used in the war were not really behind the times either.
Figures for the Blenheim are from data sheets. By Mid 1941 the British were well into expanding the size of airfields from what they were in 1935-37. Stirling may have been required to lift off the runway in 500yds (not clear 50ft) which put a real kink in it's designNumbers I've quoted above are from data sheets, ie. real world figures. Mostly mid-1941 dated data sheets.
British big bombers typically landed at half the distance vs. what they needed to clear the 50 ft obstacle. So I'd try to focus on actual high-lift devices (that can also be used to shorten the landing distcance; the big bombers of the day didn't flew much at high AoA). Eg. Ju-52 flew already in 1932, so the 1st generation of the bomber monoplanes for RAF can copy the Junkers flap, while second generation (roughly what historically were Stirling, Halifax and Machester) can do the Fowler flap.
British bomb bays weren't actually all over the map, since the Brits had a rather limited range of bomb sizes they could carry, and the object of the designers was to get their bombers to carry as large a load of those little bombs as possible, hence the diversity in size and distribution. The only British heavy bomber that really could carry the bigger bombs without modification, say 4,000lb and over, was the Manchester/Lancaster (and the Mosquito at a stretch). The Stirling's bomb bay was longitudinally sectioned, therefore able only to carry the biggest pre-war bombs and the Halifax's complex door arrangement meant it could only carry a 4,000lb bomb with its doors slightly open, which introduced drag issues, which the aircraft was plagued with already. The Wellington's was sectioned similarly to the Stirling and the Whitley had two bays, one each fore and aft of the wing box, as well as wing cells, which again restricted the size of what could be carried.
P.13/36 New Bomber
Tare Weight (lb) 18350 16447
Crew and Parachutes (lb) (4) 800 (2) 400
Guns (lb) 144 NIL
Ammunition (lb) 520 NIL
Bombs (lb) 1000 3000
Bomb Gear (lb) 56 168
Oxygen (lb) 117 55
Total Military Load (lb) 2864 3831
Petrol (UKG) 557 529
Petrol (lb) 4289 4070
Oil (lb) 270 260
Total Weight (lb) 25773 24608
Cruising Speed (mph) 278 300
P.13/36 New Bomber
Tare Weight (lb) 18350 16447
Crew and Parachutes (lb) (6) 1200 (3) 600
Guns (lb) 144 NIL
Ammunition (lb) 520 NIL
Bombs (lb) 2500 5000
Bomb Gear (lb) 140 250
Oxygen (lb) 262 120
Total Military Load (lb) 5069 6254
Petrol (UKG) 1075 1018
Petrol (lb) 8280 7850
Oil (lb) 432 4151
Total Weight (lb) 32131 30966
Cruising Speed (mph) 275 297
P.13/36 New Bomber
Tare Weight (lb) 18350 16447
Crew and Parachutes (lb) (6) 1200 (3) 600
Guns (lb) 144 NIL
Ammunition (lb) 520 NIL
Bombs (lb) 3500 7000
Bomb Gear (lb) 196 350
Oxygen (lb) 262 120
Total Military Load (lb) 6125 8354
Petrol (UKG) 1605 1515
Petrol (lb) 12360 11670
Oil (lb) 630 595
Total Weight (lb) 37465 37066
Cruising Speed (mph) 273 295
The Junkers flap was high drag in cruising flight. Junkers didn't use on the Ju 88 though the Ju 86 and Ju 87 did.
The Halifax and Manchester were ordered off the drawing board just a few months after the prototypes were ordered (but far from flying) at just about the same time that the Lockheed 14 flew. Unless you want to delay the two British bombers by months the Fowler flap is a no-go. Stirling is even further along in the design process.
More later.
Are you sure on the Ju86 speeds. I get 325kmh max speed and cruise at 250kmh clean.
Max speed of the Hampden was 400kmh cruise at 325kmh.
I admit that I find the concept of the RAF needing more bomber designs slightly amusing. They could have done with some other types like a decent land based maritime patrol aircraft, but bombers types, they had plenty of.
Perhaps someone is indeed trying to make RAF buying more bomber designs.
I'd cut the number of the designs, even if not by much. Eg they will not buy Botha, while Hampden gets the torpedo (torpedos?) earlier so there is no need for Beaufort.
No Beaufort, no Beaufighter?
Have Bristol make a big 2-engined fighter from ground-up from 1937, that is still smaller than historical Beaufighter?
he Wellington's bomb bay was a single long one with three longitudinal sections divided by two bomb beams.