Flying through an ITCZ
All the talk in this thread of ITCZs, hard CBs and turbulence reminded me of a transit I made in a MK2 Vulcan in Dec 65 between Darwin and Singapore. I was flying at 56,000 ft and at the top-of drop for Singapore encountered an ITCZ that stretched from horizon to horizon with giant CBs still pushing upwards well above my altitude. The ride became somewhat hairy with the g meter fluctuating rapidly between + 3g and - 1.5 g and the aircraft shrouded in St Elmos Fires. However, the worst part was trying to descend to Singapore. The uplift from the CBs was so great that even with the throttles closed and full airbrake I could hardly get any kind of rate of descent and stay short of MNE (never exceed Mach ). Of course, at that height,the gap beween MNE and stalling speed doesn't give you much of a leeway. I could imagine an aircraft getting into serious difficulties if the pilot allowed the speed to depart this gap.