Originally Posted by
clubord
Since landing on the 28's is a short taxi, possibly could have been the exhaust from the APU being started.
I think that's exactly it. Just as you sometimes have dripping from a car exhaust pipe, you can get it from the APU exhaust. This is a natural part of the combustion process.
http://mechanics.stackexchange.com/q...he-car-signify
(I once worked for the Boeing Company AND I stayed at a Holiday Inn Express)