Shipments of plutonium which are subject to 10 CFR 71.88(a)(4) must comply with the following:
(a) Each package containing plutonium must be secured and restrained to prevent shifting under normal conditions.
(b) A package of plutonium having a gross mass less than 40 kg (88 pounds) and both its height and diameter less than 50 cm (19.7 inches) -
(1) May not be transported aboard an aircraft carrying other cargo required to bear a Division 1.1 label; and
(2) Must be stowed aboard the aircraft on the main deck or the lower cargo compartment in the aft-most location that is possible for cargo of its size and weight, and no other cargo may be stowed aft of packages containing plutonium.
(c) A package of plutonium exceeding the size and weight limitations in paragraph (b) of this section -
(1) May not be transported aboard an aircraft carrying other cargo required to bear any of the following labels: Class 1 (all Divisions), Class 2 (all Divisions), Class 3, Class 4 (all Divisions), Class 5 (all Divisions), or Class 8; and
(2) Must be securely cradled and tied down to the main deck of the aircraft in a manner that restrains the package against the following internal forces acting separately relative to the deck of the aircraft; Upward, 2g; Forward, 9g; Sideward, 1.5g; Downward, 4.5g.