Iah-ord-lhr
The reason for the IAH flight to LHR via ORD was simple, Bermuda II prohibits BA flying from IAH to LHR. Direct flights from IAH to London have to go to LGW.
Routing via ORD allowed a flight from IAH to connect to other BA "oil" flights at LHR to places such as DME, LOS, ABZ etc.
It will all change at the end of March 08, when open skies permits direct flights from IAH to LHR.
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