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I wonder if a bomber designed from the start with no defensive armament would have suffered overall less losses, a cruising speed near 300MPH would have given night fighters and flak a bigger problem.
Except, of course, The defenseless bombers would suffer higher casualties as the defending fighters would have no return fire to contend with, which means that they can press their attacks closer and longer. Plenty of reports of bomber formations being stalked by fighters that remained just outside effective gun range, that might make one or two half-hearted passes without risking return fire. Can this be said for unarmed bombers? I think not. The only thing to end a fighter attack on an unarmed bomber is the limit of the fighter's range/endurance and ammo.
It might have but trying to cruise at 300mph is not easy for a large plane, especially one designed in the late 30s. Granted a 4 engine "fast" bomber would not have to keep the legacy fuselage of the Lancaster and Halifax if reduced to a 3-5 man crew.
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However whatever plane is being designed in the late 30s has to operate out of the existing airfields or the size of the airfields in the foreseeable future,
NOT the airfields that would exist in 1944-45. This means the thick, high drag wings (Fowler flaps and other aerodynamic trickery helps a lot more on landing than taking off) cannot be totally abandoned.
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Do you have a source for that cruise speed?The cruise speed of the first model of the Lockheed Constellation cruised at 340 mph (295 knots) and entered service in mid-1943. It could have been done, but USAAF planners had decided that bombers needed to have heavy defensive armament.
I suspect -- I've not read the actual research -- that two major factors in the increase in casualties for bombers with heavy defensive armament was the increased crew size, which resulted in more casualties per aircraft shot down and in lower bombloads. Each one of those added weight -- I'd estimate at least 1,000 lb per turret and 250 lb per non-turreted flexible gun without gunners, plus 250 lb per position for gunners. Some turrets added a great deal of drag, but leaving that aside, an aircraft with the MTOW of a B-17 without the heavy and draggy turrets could carry 7,000 lb bombs to the same distance one with all the defensive weapons could carry 4,000, which would drop the aircraft required for a given mission by 75%, that is if one needed 1000 B-17s, each with ten crew members, to fulfill a mission, you'd need 250 defenseless bombers, each with no more than four. Even if both groups lost 20 bombers, the defenseless bombers would result in 80 casualties, while the armed bombers would lose 200. I don't think it would be that bad for the defenseless bombers.
It might have but trying to cruise at 300mph is not easy for a large plane, especially one designed in the late 30s. Granted a 4 engine "fast" bomber would not have to keep the legacy fuselage of the Lancaster and Halifax if reduced to a 3-5 man crew.
However whatever plane is being designed in the late 30s has to operate out of the existing airfields or the size of the airfields in the foreseeable future,
NOT the airfields that would exist in 1944-45. This means the thick, high drag wings (Fowler flaps and other aerodynamic trickery helps a lot more on landing than taking off) cannot be totally abandoned.
For Example a B-24 ( Liberator VI) needed 2100 yds to take-off and clear 50ft at 62,000lbs. A Fortress III needed 1560yds at 64,000lbs
A Halifax I (with Merlin X engines) need 1400yds at 59,000lbs, A Halifax II (with Merlin XX) needed 1200yds at 60,000lbs and a Lancaster I needed 1500 yds at 68,000lbs and 1200yds at 45,000lbs.
Everybody agrees the B-24 had the lowest drag wing, Now can you actually fly the B-24 from British 1938-39-40 airfields? even if you chop 10,000lbs out of it?
A Mosquito IV needed 840 yds at 21,462lbs using 12lbs of boost. but was only carrying four 500lb bombs.
Hooker only gets to RR and modifies the supercharger in late 1939, so any planning done in 1938-39 has to be done with the Merlin X in mind.
Perhaps but then, due to the size/complexity of the big bombers they were always going to be a bit behind single engine fighters in aerodynamics/structure.
Trying to design a 50,000lb airplane (and the tooling to build it) is always going to take longer than a 10,000lb airplane.
The Connie was an Amazing airplane but flying the Prototype in Jan 1943 (or even several months earlier) means it is two-three years after the decision to build three factories for the B-17 and use five factories to build B-24s. Brand new factories were built to build the engines for both programs. Trying to shift such programs to new types was going to be extremely difficult.
This brings us back to what was possible when. Could you build an unarmed heavy bomber, using the knowledge of the time, that had high enough performance to keep losses to a minimum in the late 30s or 1940-42? And using airfields of the time?
Progress was moving quick. The US did have the A-26 flying in mid 1942 with one of the most advanced wings used in WW II. However even with a pair of R-2800 engines and top speed of 355mph or over it still cruised at around 280-290mph.
The NA XB-28 is also instructive.
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granted it has three turrets but it used the same engines as an early P-47 and the same turbos. It was roughly 50mph slower than P-47. Top speed was 370mph and the cruise was under 300mph. Do we think that deleting the three remote gun mounts and two gunners is going to gain 30-40mph?
And that is a major problem for the "high speed" bomber. It has to cruise fast. The B-28 or A-26 went over 22,000lbs empty and well over 30,000lbs loaded (over 35,000lbs full load) so trying to accelerate from "lean" cruise to top speed (or even a high cruise) was going to take a while, time the plane is not going to have if bounced. These radial engine bombers could use 300-400 gallons an hour if cruised at rich settings and well over 500 gallons an hour(8 gallons a minute) at full power.
Liquid cooled engines may do better.
The B-29 Program had full scale mock ups being inspected in Nov of 1940, just a few months after the BoB. First prototype flew in Sept 1942, just 35 days after the B-17E makes it's first combat mission in Europe.
At what point do you make the gamble for an unarmed (or lightly armed) high speed bomber?
Depending on your enemy to make mistakes or fumble his engine programs/aircraft development is also not very good planning. Depending in 1941-42 that the Germans would NOT develop (and have in mass production) a 425-440mph single engine day fighter with four 20mm cannon by 1944 is not good planning. Depending on the Germans to be using converted bombers as night fighters or still be using Bf 110s in late 1943 and 1944 is also not good planning.
What would have happened if the Germans had lowered the compression in their engines and used higher boost?
What would have happened if the Germans had gotten two stage superchargers into use sooner?
How well would an unarmed, high speed bomber have fared against allied planes?
What kind of bomber do you need to penetrate airspace defended by P-47s or Spitfire MK XIVs?
Yes. See, for example, the Mosquito. Before that, the US B-9 was faster than its contemporary fighter aircraft.
You're correct that progress was moving quickly in the mid to late 1930s, but that progress was equally beneficial for large aircraft as for fighters. In any case, I think the main barrier to the pre-war development of an unarmed or minimally armed, fast heavy bomber was not technological but internal air force ideology, that being that the bomber will always get through without fighter escort; this assumption drove the design of US bombers. When the USAAF actually had to deal with an enemy with a powerful air force defending its cities, it found its bombers wouldn't get through without unsustainable losses (I think they also found that one or two raids wouldn't cause an enemy to sue for terms).
Designing a lightly armed or unarmed strategic bomber would require the concomitant design of a high-performance, long ranged escort fighter. (No doubt somebody will blame Congress, but before doing, they should remember that the USAAF leadership was politically well-connected enough so that Congress would generally follow the USAAF's priorities; the pot of money may not have been infinite, but the USAAF had a great deal of influence over how their share of that pot was distributed, and they didn't distribute it to long-ranged escort fighters) Here, I think that the Luftwaffe, with its flawed zerstorer concept was actually considering enemy fighters as a serious threat to its bombers, showed somewhat better planning than did the USAAF. The USN, which included fighters in its carrier aviation planning, was also considering enemy fighters were a problem -- those fighters were there, at least partly, to prevent enemy fighters from decimating attack aircraft -- also showed a greater level of foresight.
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In reverse, the Navy example is flawed because the Navy aircraft were restricted in size and power. They had to fit on the carrier and they had to be single engine. If you are using the same engine in your fighter and in your attack aircraft (carrying 500-1000lb bomb or a torpedo) then the attack aircraft is going to be slower than the fighter and perhaps shorter ranged when carrying the strike load. All have to take off and land from a certain sized "runway".
The Army can use twin engine bombers (some foreign nations used three) and gain range/payload over single engine aircraft.
By the time you get to the Martin B-10
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you have a plane at the end of 1933 that had a normal range of around 590 miles, a max range of 1240 miles and a ferry range of 1830 miles.
or would when it became the B-10B. In any case the ranges were beginning to exceed what single engine fighters could achieve and still keep their performance. With the Armies interest in the B-15 and B-17 the range of fighters was falling further behind what the bombers could do.
The Boeing 299 was credited with a range of 2040 miles while carrying 2573 lbs of bombs. This was in 1935 with 750hp P & W Hornet engines. No single engine fighter in existence or in the planning stages could come close to that range using the engines available or promised at the time.
The clue is in the name. Early B-17s were not covered in guns; they were dubbed Fortresses as they were designed to act as a longer-ranged coastal defence fortress.Was the B-17 really designed to attack foreign cities or was it really designed as a long-range adjunct to coastal artillery?
The clue is in the name. Early B-17s were not covered in guns; they were dubbed Fortresses as they were designed to act as a longer-ranged coastal defence fortress.
Upon touring the Boeing plant and witnessing the first B-17s roll off the assembly line, "An awestruck reporter called the aircraft a 'Flying Fortress,' and the name stuck."The clue is in the name. Early B-17s were not covered in guns; they were dubbed Fortresses as they were designed to act as a longer-ranged coastal defence fortress.