Agaricus bisporus
24th Apr 2007, 09:52
A question for anyone who flies 700 - 900 series 737s.
When setting the LAND ALT before departure do you round up or round down the arrival rwy altitude? Does it matter - after all, only 50 feet is involved. What is Boeing Standard, and why?
My feeling is that as the cabin lands "slightly pressurised" ( Boeing OM Vol II) rounding it down could result in a landing pressure equivalent to up to 50 ft below the surface, plus the "slightly pressurised" element, plus any barometric variable, ie QNH about to change) which could cause a pressure bump in the cabin, whereas rounding up would minimise this. Previous company insisted vehemently that rounding up was essential, present one doesn't seem to have much of a view. Our trainers tell different stories.
Ideas?
When setting the LAND ALT before departure do you round up or round down the arrival rwy altitude? Does it matter - after all, only 50 feet is involved. What is Boeing Standard, and why?
My feeling is that as the cabin lands "slightly pressurised" ( Boeing OM Vol II) rounding it down could result in a landing pressure equivalent to up to 50 ft below the surface, plus the "slightly pressurised" element, plus any barometric variable, ie QNH about to change) which could cause a pressure bump in the cabin, whereas rounding up would minimise this. Previous company insisted vehemently that rounding up was essential, present one doesn't seem to have much of a view. Our trainers tell different stories.
Ideas?