Dear Mr. Lochhead,
Here are a few videos that I described in class on Monday. The real things are always better...
STS-123 Landing [YouTube] - You can start to see the APU plume in infrared at 5:05, a little bit in visible at 5:15, and very clearly near wheel stop at 6:05. The APU plume is normal, happens after every landing. It never looks this cool, though, usually it is invisible. For the flame to appear so clearly, there was a favorable combination of (1) a night landing and (2) very low wind.
