I know about the DC issue from a first hand experience. I was testing a high power "wifi" for range. My pilot flew the aircraft from St Mary's airport in Maryland toward DC. We still had good contact with the ground station, but air traffic control was telling the pilot that it was time to go back. We accomplished the desired measurement. I was ready to head back to the airport. The aircraft was poorly pressurized and we had been over 15,000 for an extended period. If I was getting light headed, I'm pretty sure the pilot was as well.
At least you didn’t get an Apache escort!