The following scenario puts an aerial tanker in a N/S towline starting over KSFO at 8000 ft AGL. The tanker uses the KC-135 model, but you can use any model. Note that AI aircraft do not react to wind, therefore your speed and bank angle will have to vary along the orbit since your "user" aircraft *does* react to the wind. I recommend using the T-38 as your airplane for four reasons: (1) it has a radar screen which may be needed to find the tanker; (2) it has the speed to catch the tanker; (3) it uses a JSBSim FDM, which means it can onload fuel; (4) it has a green light added to the instrument panel, between the fuel gauges, which comes on when you are in the refueling envelope. The A4F also has a refueling capabilty using YASim, with a green light in the fuel level gauge. It also has a nav-display which can be set to display the A/A TACAN position of the channel listed below. Right now the air refueling envelope is very loose, and I plan on tightening it up in the future. Currently no aerodynamic effects of refueling are modeled (i.e downwash, bow wave, vortices). Dave Culp, davidculp2 at comcast.net ESSO1 040X tanker tanker Models/Geometry/KC135/KC135.xml tanker_racetrack.xml ESSO 1 1