Originally Posted by
CDKing
At least i see where she got the 16,000 feet thing from. Not sure maybe there was a mechanical problem with vaccum generator that is used to flush when under 16K feet
See the top of page 5 on the A320 Flight Crew Operating manual (found via googe search)
Water/Waste
That's exactly the problem that I experienced on a recent 320 flight MSP to DCA. The vacuum generator was not working and we were instructed to not use the lavs until we received 16,000 feet. Fortunately, the pilot let us know the reason, which probably helped to minimize grumbling among the pax.