I was flying on UA192 today and listening to ATC communications as we began our descent into IAD around 1 PM today.
The pilot on US840 missed a few of the ATC's directions, then stated, "It's hard to do with this mask on."
Why would the pilot of US840 need what I assume would be an oxygen mask on? FWIW, US840 flew DFW-PHL today, and arrived at 2:06 PM today.