49 CFR § 1544.209 - Use of metal detection devices.
(a) No aircraft operator may use a metal detection device within the United States or under the aircraft operator's operational control outside the United States to inspect persons, unless specifically authorized under a security program under this part. No aircraft operator may use such a device contrary to its security program.
(b) Metal detection devices must meet the calibration standards established by TSA.
The following state regulations pages link to this page.