PPRuNe Forums - View Single Post - how to handle a rapid decompression over the Pacific ?
Old 16th Sep 2011, 00:30
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HarryMann
 
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D. P Davies pointed out that there are at least two ways of getting down fast.

The Mmo/Vmo route, anticipating the switch altitude to pickup Vmo.

Then it was possible to decelerate at constant altitude, hang out a few drag producing devices (e.g. u/c and/or spoilers ) and then come down slower & steeper.

For a veriety of reasons, the former is usually the best method, especially as it starts to get the cabin altitude down immediately....

Both methods (he suggested) required a sensible margin above level-off height (e.g. 10,000 ft) to initiate the levelling off in good time.

*The ear also doesn't like (can't handle) rapidly increasing pressure as much as reducing pressure. I believe I was once told that comfortable rapid descents should be limited to about 8000 ft/min... for that reason, though of course oxygen content of the cabin air would rate higher on the wish list, than some discomfort.

* Am quite prepared to be corrected on the above anecdote

Last edited by HarryMann; 16th Sep 2011 at 00:50.
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