We were climbing out of Washington National, (DCA) on the way to Charleston, SC (CHS) I I remember correctly. We got a “TRAFFIC, TRAFFIC” alert but didn’t see anything due to some clouds. We had him on the MFD but no altitude or anything else. We continued and then got a “STOP CLIMB, STOP CLIMB FOLLOWED BY “DESCEND, DESCEND). We reported this to ATC right away and they said “don’t go there” which is a phrase I don’t believe is in the controllers handbook. This was very confusing. We were crossing behind the unknown A/C at maybe a 45 degree so all this only took about 20 seconds to play out. We then got “CLEAR OF TRAFFIC”.
Watched TV that night. Turned out later that AF-1 was carrying Bill Clinton. Their transponder was probably turned off and that was the TRAFFIC alert. He was probably escorted by Guard or Reserve fighters who heard the transmission and one of them turned on their transponder and gave us the two other commands. I’ll never know what really took place that day.
ATC made a mistake by giving us vectors too close to AF-1. Nothing came of it and we never got a word from ATC. They were very cool about it.
Military fighters, when maneuvering, are hard for a commercial TCAS to track. This is especially true when there are several in formation. Only lead should have his transponder in the full mode. Otherwise, they would all be getting conflicting commands.
Once, over Ohio, where there is a refueling track, We got “TRAFFIC, TRAFFIC” from a single aircraft. It was a tanker. It wasn’t until we were passing that and I put down from studying my POH (yeah right) we got about 10 fighters in trail waiting to hook up and take a drink. ATC never advised there were 10 in trail. No conflict, though. When they pulled off, they turned away.