#### § 175.701 Separation distance requirements for packages containing Class 7 (radioactive) materials in passenger-carrying aircraft.

(a) The following table prescribes the minimum separation distances that must be maintained in a passenger-carrying aircraft between Class 7 (radioactive) materials labeled RADIOACTIVE YELLOW-II or RADIOACTIVE YELLOW-III and passengers and crew:

| Transport index or sum of transport indexes of all packages in the aircraft or predesignated area | Minimum separation distances | |
| --- | --- | --- |
| Centimeters | Inches |
| 0.1 to 1.0 | 30 | 12 |
| 1.1 to 2.0 | 50 | 20 |
| 2.1 to 3.0 | 70 | 28 |
| 3.1 to 4.0 | 85 | 34 |
| 4.1 to 5.0 | 100 | 40 |
| 5.1 to 6.0 | 115 | 46 |
| 6.1 to 7.0 | 130 | 52 |
| 7.1 to 8.0 | 145 | 57 |
| 8.1 to 9.0 | 155 | 61 |
| 9.1 to 10.0 | 165 | 65 |
| 10.1 to 11.0 | 175 | 69 |
| 11.1 to 12.0 | 185 | 73 |
| 12.1 to 13.0 | 195 | 77 |
| 13.1 to 14.0 | 205 | 81 |
| 14.1 to 15.0 | 215 | 85 |
| 15.1 to 16.0 | 225 | 89 |
| 16.1 to 17.0 | 235 | 93 |
| 17.1 to 18.0 | 245 | 97 |
| 18.1 to 20.0 | 260 | 102 |
| 20.1 to 25.0 | 290 | 114 |
| 25.1 to 30.0 | 320 | 126 |
| 30.1 to 35.0 | 350 | 138 |
| 35.1 to 40.0 | 375 | 148 |
| 40.1 to 45.0 | 400 | 157 |
| 45.1 to 50.0 | 425 | 167 |

(b) When transported aboard passenger-carrying aircraft packages, overpacks or freight containers labeled Radioactive Yellow-II or Radioactive Yellow-III must be separated from live animals by a distance of at least 0.5 m (20 inches) for journeys not exceeding 24 hours, and by a distance of at least 1.0 m (39 inches) for journeys longer than 24 hours.

(c) Except as provided in [paragraph (d)](/on/2024-09-24/title-49/section-175.701#p-175.701(d)) of this section, the minimum separation distances prescribed in [paragraphs (a)](/on/2024-09-24/title-49/section-175.701#p-175.701(a)) and [(b)](/on/2024-09-24/title-49/section-175.701#p-175.701(b)) of this section are determined by measuring the shortest distance between the surfaces of the Class 7 (radioactive) materials package and the surfaces bounding the space occupied by passengers or animals. If more than one package of Class 7 (radioactive) materials is placed in a passenger-carrying aircraft, the minimum separation distance for these packages shall be determined in accordance with [paragraphs (a)](/on/2024-09-24/title-49/section-175.701#p-175.701(a)) and [(b)](/on/2024-09-24/title-49/section-175.701#p-175.701(b)) of this section on the basis of the sum of the transport index numbers of the individual packages or overpacks.

(d) *Predesignated areas.* A package labeled RADIOACTIVE YELLOW-II or RADIOACTIVE YELLOW-III may be carried in a passenger-carrying aircraft in accordance with a system of predesignated areas established by the aircraft operator. Each aircraft operator that elects to use a system of predesignated areas shall submit a detailed description of the proposed system to the Associate Administrator for approval prior to implementation of the system. A proposed system of predesignated areas is approved if the Associate Administrator determines that it is designed to assure that:

(1) The packages can be placed in each predesignated area in accordance with the minimum separation distances prescribed in [paragraph (a)](/on/2024-09-24/title-49/section-175.701#p-175.701(a)) of this section; and

(2) The predesignated areas are separated from each other by minimum distance equal to at least four times the distances required by [paragraphs (a)](/on/2024-09-24/title-49/section-175.701#p-175.701(a)) and [(b)](/on/2024-09-24/title-49/section-175.701#p-175.701(b)) of this section for the predesignated area containing packages with the largest sum of transport indexes.