He said it is too soon to tell what rules, if any, may be changed as a result of the review. The TSA has never previously sought to regulate small private planes, and in the past has focused on 15,000 larger and faster private jets that it said in a report "could be used effectively to commit a terrorist act."

A 2008 TSA proposal, widely opposed by businesses and aviation groups, seeks to require private-jet passengers to be checked against watch lists. It also aims to require jet operators to keep weapons, including pocket knives, off their planes, and to force 315 airports used only by private planes to enact security plans.

Smaller planes haven't received much attention from anti-terror officials because the damage they can cause is generally much less than a large commercial airliner, which can carry several thousand gallons of fuel and reach speeds of over 500 mph. As of December 2008, there were 7,274 commercial and cargo planes operated by U.S. air carriers.

The pilot in last week's incident, Joseph Stack, 53, appears to have rigged his small Piper Dakota plane with extra fuel in order to do more damage. Stack, a software engineer disgruntled over tax problems with the IRS, may have had a 55-gallon drum of fuel in the four-seat, single-engine plane when he crashed into the building, said Capt. Jeff Solomon, Austin's acting fire marshal.