14 C.F.R. § 91.607
(a) Notwithstanding any other provision of this chapter, no person may operate a large airplane (type certificated under the Civil Air Regulations effective before April 9, 1957) in passenger-carrying operations for hire, with more than the number of occupants—
(2) Approved under Special Civil Air Regulations SR-387, SR-389, SR-389A, or SR-389B, or under this section as in effect.
However, an airplane type listed in the following table may be operated with up to the listed number of occupants (including crewmembers) and the corresponding number of exits (including emergency exits and doors) approved for the emergency exit of passengers or with an occupant-exit configuration approved under paragraph (b) or (c) of this section.
| Airplane type | Maximum number of occupants including all crewmembers | Corresponding number of exits authorized for passenger use |
|---|---|---|
| B-307 | 61 | 4 |
| B-377 | 96 | 9 |
| C-46 | 67 | 4 |
| CV-240 | 53 | 6 |
| CV-340 and CV-440 | 53 | 6 |
| DC-3 | 35 | 4 |
| DC-3 (Super) | 39 | 5 |
| DC-4 | 86 | 5 |
| DC-6 | 87 | 7 |
| DC-6B | 112 | 11 |
| L-18 | 17 | 3 |
| L-049, L-649, L-749 | 87 | 7 |
| L-1049 series | 96 | 9 |
| M-202 | 53 | 6 |
| M-404 | 53 | 7 |
| Viscount 700 series | 53 | 7 |
(b) Occupants in addition to those authorized under paragraph (a) of this section may be carried as follows:
(c) No person may eliminate any approved exit except in accordance with the following: