49 C.F.R. § 175.704 Plutonium shipments.
Title 49 - Transportation
Shipments of plutonium by air which are subject to 10 CFR 71.88(a)(4) must comply with the following: (a) A plutonium package weighing less than 40 kg (88 lbs) and having its height and diameter both less than 50 cm (19.7 in), 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. No other type of cargo may be stowed aft of a plutonium package. (b) A plutonium package must be secured and restrained to prevent shifting under normal transport. A plutonium package weighing 40 kg (88 lbs) or more must be securely cradled and tied down to the main deck of the aircraft such that the tied down system is capable of providing package restraint against the following inertial forces acting separately relative to the deck of the aircraft: Upward, 2g; Forward, 9g; Sideward, 1.5g; Downward, 4.5g. (c) A plutonium package weighing less than 40 kg (88 lbs), and having its height and diameter both less than 50 cm (19.7 in), may not be transported aboard an aircraft carrying other cargo required to bear an “Explosive A” or an “Explosive 1.1” label. Any other plutonium package may not be transported aboard an aircraft carrying other cargo bearing any of the following hazardous material labels: Explosive A; Explosive B; Explosive C; Explosive 1.1, 1.2, 1.3, 1.4, 1.5 or 1.6; Spontaneously Combustible; Dangerous When Wet; Organic Peroxide; Non-Flammable Gas; Flammable Liquid; Flammable Solid; Flammable Gas; Oxidizer; or Corrosive. [Amdt. 175–53, 60 FR 50333, Sept. 28, 1995]
Title 49: Transportation
PART 175—CARRIAGE BY AIRCRAFT
Subpart C—Specific Regulations Applicable According to Classification of Material
§ 175.704 Plutonium shipments.

