there was a plane sent from Washington (originally seeing flight 77) that scooted up torwards flight 93. They got there a few minutes after the crash.
From the 9/11 commisison report
United 93 crashed in Pennsylvania at 10:03:11, 125 miles from Washington, D.C. The precise crash time has been the subject of some dispute.The 10:03:11 impact time is supported by previous National Transportation Safety Board analysis and by evidence from the Commission staff ’s analysis of radar, the flight data recorder, the cockpit voice recorder, infrared satellite data, and air traffic control transmissions.168
Five minutes later, the Command Center forwarded this update to headquarters:
Command Center: O.K. Uh, there is now on that United 93.
FAA Headquarters:Yes.
Command Center: There is a report of black smoke in the last position I gave you, fifteen miles south of Johnstown.
FAA Headquarters: From the airplane or from the ground?
Command Center: Uh, they’re speculating it’s from the aircraft.
FAA Headquarters: Okay.
Command Center: Uh,who, it hit the ground.That’s what they’re speculating,that’s speculation only.169
The aircraft that spotted the “black smoke” was the same unarmed Air National Guard cargo plane that had seen American 77 crash into the Pentagon 27 minutes earlier. It had resumed its flight to Minnesota and saw the smoke from the crash of United 93, less than two minutes after the plane went down. At 10:17, the Command Center advised headquarters of its conclusion that United 93 had indeed crashed."
Perhaps he was mistaken about it being reported by a fighter