Originally Posted by
NetJets Germany
Sorry, completely unrelated to your original question about compensation, but I just wanted to genuinely ask: Are you sure that was the rational behind lowering the altitude? Air pressure is higher closer towards the ground, so flying at a less high altitude would have exacerbated the risk, not reduce it, right? I would guess that one logical course of action was to reduce speed in order to reduce air pressure on the windscreen. Perhaps the reduction in altitude was also to protect the pilots in case the screen did break properly, so that they would not have to operate in low-oxygen conditions in the cockpit. Then again the speed would still have been far too high to be able to see anything in the cockpit, unless they had some serious helmets at hand (Think of driving a convertible at 150+mph without a windscreen). Anyway, enough armchair-philosophying from me, I am not an aircraft engineer and am just genuinely curious about the correct course of action to take in such an event.
Cockpit windows have two layers of glass.
If the outer layer is cracked, there is no limitation.
If the inner layer is cracked, descent is required and the flight crew will manually reduce the cabin altitude to lower that differential and to prevent a risk of blowing out the damaged window. (I.e from FL350 vs cabin alt around 8000ft to FL150 vs around 4000ft).
It is the subsequent lower level and increased fuel burn that will dictate whether the aircraft can continue to destination or need to divert. Hope that makes some sense.