Why would an extension of US DST cause problems for air travel?

[The_Composer]

This link from Yahoo! mentions that extending daylight savings time from March through November would cause problems for the air industry.

Energy Secretary
Samuel Bodman has warned it would “raise serious international harmonization problems for the transportation industry.”

The Air Transport Association, which represents major U.S. airlines, argues that it would throw U.S. international schedules further out of sync with Europe. It says a two-month extension, the initial proposal, would cost the U.S. airline industry $147 million and disrupt overseas travel.

“This is an ultimate disaster for airlines and all of our customers, who will be horribly inconvenienced,” says James May, the group’s president and CEO.

Why?

[SmackFu]

A PDF from them explaining it.

My summary: flights to Europe have to land at a specific time (in “slots”) because that’s how they do it over there. If Europe and the US are out of sync with regard to DST, the domestic flights that feed into those international flights then have to be moved an hour as well. But the schedule change is only for those 7 weeks of out-of-sync-ness, and the airlines don’t want to do this.

Something else to consider is that $147 million is small change for the airline industry.