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Hi buddy, I was talking about you just last week. Forever grateful for your hospitality many years ago.Totally off-topic : my, my, look who's back
Don't mention itHi buddy, I was talking about you just last week. Forever grateful for your hospitality many years ago.
I have been following this forum and others, and have been reading many of your excellent posts over the years.
The higher you go the harder it is to generate both power and lift, also the higher you go the more difficult it is to hit anything other than a city. The Spitfires that intercepted Ju 86s were also modified with various things removed (guns armour radios) to lose weight. At the heights involved the Spitfire was so "marginal" on performance that one gun not firing caused it to stall. As nuisance raids raids with no losses they were worth it, when they started to be shot down or even hit, it wasnt worth the risk for the few they had in service. No matter what the bomb site dropping dumb bombs from 40,000+ ft means you cant hit anything that a small bomb could damage.I am fascinated by the concept of the high altitude bomber. At first it seems a clear concept: a bomber so high it is difficult to shoot down by interceptors or anti-aircraft guns. The most famous one is probably the Junkers Ju 86 which was used in small numbers as a recon and as a bomber. But the paradox seems to be that the added weight of the bombs is detrimental to high altitude performance. Indeed, the Ju 86 bomber used as a mere nuisance bomber, carrying a single 250 kg bomb.
The American B-17 and B-24 were equipped with turbo superchargers and this allowed them to operate at 8-9 km (30k feet). I could be wrong but I believe the old story of the Mosquito carrying a bigger bombload than the B-17 comes from a B-17 flying at its maximum altitude. In fact, the B-17 had a payload similar to the Lancaster but no way it could carry that at high altitude.
So, what determines how much a bomber can carry at various altitudes? Let's say for instance the Heinkel He 274. This was a planned very high altitude bomber, powered by four turbocompressed DB 603s or BMW 801s, with a ceiling of 14 km (46k ft) but how much of its maximum payload of 4 ton could it carry that high? Also, would it have made a difference if it was an external payload (Fritz guided bomb) as ultimately an aircraft can fly at any altitude as long as it has sufficient speed?
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Well, you can hit something you could damage.means you cant hit anything that a small bomb could damage.
So, what determines how much a bomber can carry at various altitudes?
I could be wrong but I believe the old story of the Mosquito carrying a bigger bombload than the B-17 comes from a B-17 flying at its maximum altitude. In fact, the B-17 had a payload similar to the Lancaster but no way it could carry that at high altitude.
There were few raids, dropping small loads, so air raid sirens were not used to warn civilians. As is almost always the case with such things they got lucky, one bomb hit a bus station, killed 48 and wounded 48.Well, you can hit something you could damage.
Just not what you intended/aimed for.
Hi TomoHi-alt bomber needs to have favorable wing loading and power loading in order to be a viable hi-alt bomber.
B-17 was very good in this, and it's bomb load was far heavier than 4000 lbs. Eg. see here - with 10000 lb of internal bombs, it was still supposed to have the range of 1600 miles when flying at 25000 ft.
You know what they say about the old stories
There were also the Mosquitoes that were carrying 5000 lbs and still capable of service ceiling of 36000 ft on max weight, these being powered by very hi-alt Merlin 70 series engines. See here.
Well, the Ju86P and Ju86R were highly successful in one respect. They inspired the British to create a high altitude Wellington to emulate them. And that in turn led to a request to Stanley Hooker of RR to create a back-up engine for the original turbosupercharged radial design, which he did by combining a Merlin with the supercharger off the failed Vulture engine.
I could be wrong but I believe the old story of the Mosquito carrying a bigger bombload than the B-17 comes from a B-17 flying at its maximum altitude. In fact, the B-17 had a payload similar to the Lancaster but no way it could carry that at high altitude.
I have seen reference to Hooker using the Vulture impeller (not sure about other parts) in a test rig.I've not seen any reference to the 60-Series Merlin using the Vulture's supercharger before.
I have seen reference to Hooker using the Vulture impeller (not sure about other parts) in a test rig.
B-17 was rarely (if ever) used as designed. It was also operating well over 10,000lbs higher that it was designed which seriously affected altitude.
From Joe Baugher's web site.
B-17E...Weights: 32,350 pounds empty, 40,260 pounds gross, 53,000 pounds maximum.
B-17G... 32,720 pounds empty, 55,000 pounds normal loaded, 72,000 pounds maximum.
Expecting late model B-17s to fly in formation at over 30,000ft over Germany is like expecting the tooth fairy to shower hundred dollar bills for one tooth.
Just going by "The Merlin in perspective: The combat years (Historical series)" as I sure don't have any Merlin supercharger impellers laying aroundThat certainly makes sense, but the supercharger units between the two engines were definitely not the same. From what I have read, the 60-Series Merlin was based on the Merlin 46, although again the superchargers were different.
This is true, but the theory behind the Mossie carrying a bigger bomb load across a greater distance than the B-17 simply doesn't add up. The unfortunate off-shoot of this theory is that people use it to reinforce their ideas that heavy bombers should have been replaced with Mosquitoes.
Issues with the B-17's altitude not being what the designers had claimed arose with British use of the aircraft in 1941. Granted, these were early model B-17Cs, but they struggled at altitudes above 25,000 ft, suffering severe icing. One was taken to 30,000 feet before its controls froze and it spiral-dived into the ground, killing all aboard.