[Mr. Silverback]

Why is the track of UPS902, as supplied by FlightAware.com, perpendicular to the path of the contrail?

For the same reason that this set of power lines appears to be nearly vertical: Foreshortening.

That's also the same reason an airliner contrail I saw today appeared to be a few degrees off vertical even though the plane was definitely parallel to the earth. It was close to sunset so I even got a flash of "fire" for part of the "ascent." No camera at hand, though.

As for the "different locations" in your other post, that's the result of different zoom settings. This is discussed on this page. And here are Warren's original photos in a zip file.

[TigersEye]

Foreshortening does not explain why the contrail is at a right angle to the projected flight path. LOL

[TigersEye]

As for the "different locations" in your other post, that's the result of different zoom settings.

Then why do the contrails all match up in size in the overlaid pic? The point is that the contrail changed shape and position quite a bit and the vehicle also move a good deal south yet it made little forward progress in that time. Is the wind blowing the contrail and the plane south faster than the plane is flying east? Really?