I’s been a while, but there I was, letting down into the Tri-Cities area after a three-hour flight when the Skyhawk I was driving coughed. Since I hadn’t touched any engine controls, there was no good reason for the cough and I immediately started to think about landing some place other than the regional airport, now some 20 nm away. I told the approach controller what was going on and that we would not accept a delay. I was immediately cleared to land on any runway at Tri-Cities and asked for fuel and souls on board. Once the formalities were out of the way, the controller pointed out the Interstate…