I really liked the wing position on this shot. The 1D Mark III is notorious both for excellent servo AF and also very inconsistent autofocus. Top tip, put tracking speed on slowest! I took a load of bird in flight shots today with this setting using the 70-200 f/2.8 IS L II with the 1.4x II converter fitted. Correctly focussed shots over 90% of the time!
Canon EOS-1D Mark III, f/5.6 @ 280 mm, 1/1000, ISO 400