[QUOTE=galdri]If a Vulcan came apart during a 2G pull, something must have been seriously wrong! And it makes me wonder, how all the rest of the fleet survived for years in the low level role with out every single one of them braking up. Low level flying at high speed puts a very high strain on the airframe (and we are talking WAY more than 2G´s). Besides, the Pop-up Manuover is NOT a gentle pull. It will probably be around 3.5-4G´s on the way up, and a similar amount pulling out of the ´reverse half-cuban´. So if a Vulcan broke up at 2G´s, it must have been seriously redesigned! Otherwise, you would have Vulcan remains all over the place, and no surviving crewmembers.
Airframe limitations are not just about straight G. Aircraft have max manoevring speeds defined as Vman. This speed is defined as the limit to which maximum control deflection can be used by the pilot up to the max straight G limitation. Above Vman only a third of control deflection is allowed, and in some aircraft such as VX770 the straight G limit was much lower. This restriction of allowable control deflection particularly applied to aileron control because of the twisting forces applied to the wing. In the case of VX770, the pilot was limited to 1.75G and 360kts for the planned rolling/pull manoevre. What he actually did was to perform the manoevre at 420kts with a substantial aileron deflection way above Vman. The twisting force on the starboard wing caused a failure of the leading edge structure which then caused the skin to peel back ‘like a sardine tin’. All this occured with a G loading estimated at less than 2G.
The production B1 had a redesigned wing planform and leading edge structure which meant the operational limits were higher than VX770 – but not by much.
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