Airbus Comfort Mode??
I recently noticed an A340 transiting through our airspace with an oscillating Mode C 340-341-340. When queried, the pilot said they were operating in a 'Comfort' Mode on cruise which allowed the aircraft to deviate up and down about +/-50' for passenger comfort. I have never heard of this before, any Airbus drivers out there that can confirm this feature and maybe clarify how it works? Thanks in advance