ORIGINAL: hook57
Hhmmm. 14 CFR part 91.137 and 91.141
But if you read the clause you see that the FAA is not the authority. The TSA authority goes back to the 50's or 60's and just recently added to the FAR, but IMO not necessary.
At anyrate I should have said day to day operations. Terrorist threats, and disasters are clearly special cases which need extreme measures.