The head of the Transportation Security Administration says the close-quarter body inspections causing a furor among some passengers and pilots are unavoidable in a time of terrorist threats.

John Pistole tells CBS's "The Early Show" he understands public distaste for more intense security procedures, particulary hand pat-downs. He called it a "challenge" for federal authorities and airport screeners.

But Pistole said the attempted bombing of a U.S. bound plane last Christmas and the effort to ship packages with bombs to this country on cargo planes more recently makes tougher security necessary. He said Friday, "The bottom line is, we're trying to see that everybody can be assured with high confidence that everybody else on that flight can be properly screened."