Hmmmm, you raise some interesting points. That said, I agree with Ethan that the rainbow in question is a Fire Rainbow. I had never seen one in real life unti

Hmmmm, you raise some interesting points. That said, I agree with Ethan that the rainbow in question is a Fire Rainbow. I had never seen one in real life until just recently, but I have seen several in the sky over Paris this summer, and they have the same distinctive colour distribution. Having had the opportunity to see a few, I can tell you that although it is true that the sun needs to be behind the aircraft, the definition of behind is very loose indeed - typically the fire rainbows that I have seen are about a quarter of the sky away from the sun itself (I'm starting to wonder if it's actually 46° away, having read Ethan's explanation), so there is a large expanse of sky where this effect could be seen. I agree that this is a low-speed manoeuvre though, and not an example of a transonic cloud - have a look at this photo from RAAF Amberley earlier this year: http://www.defence.gov.au/media/download/2010/Jun/20100607/20100603raaf8490713_0040.jpg http://www.defence.gov.au/media/download/2010/Jun/20100607/2... - it has the same cloud structure as the F22 photo.