The Senate has approved a two-year, $35-billion Federal Aviation Administration bill, including $8.1 billion for Airport Improvement Program construction grants, but it looks like another extension is in the cards.

The FAA authorization bill, which the Senate passed on March 22 by a 93-0 vote, next would go to conference with the three-year $53.5-billion FAA bill that the House passed last May.

But there are some major differences between the two measures.  That makes it unlikely that House and Senate negotiators can strike a deal by March 31, when the current authorization expires.

Recognizing the time squeeze, the House on March 17 approved another stopgap, carrying the FAA programs through July 3.

If another extension is enacted, it would be the 12th FAA stopgap since Sept. 30, 2007, when the last multi-year FAA bill lapsed.

The AIP authorizations in both the Senate and House bills are $4 billion in 2010 and $4.1 billion in 2011.