SA405EA-D
Convert all Boeing 707-123B aircraft to the summer passenger cabin configuration (4 first class lounge, 26 first class seats, and 101 tourist class seats) by removing one coat compartment, three first class double seats and installing two additional rows of tourist class seats and LH class divider. Held by American Airlines INC, which holds 377 approved modifications in all. Last revised March 24, 1970. System: cabin, seats and restraints.
What it applies to
- Kind of product
- Aircraft
- Design holder
- The Boeing Company; The Boeing Company
- Models
- 707-100B Long Body, 707-100B Short Body
- Type certificates
- 4A21, 4A21
- On this site
- Boeing 707 9 registered
- The FAA's record
- On the FAA's site
What an approved modification is
A supplemental type certificate is the FAA's approval of a change to a certified design: a new engine or propeller, avionics, an autopilot, floats, a parachute, a larger fuel tank, an ice-protection kit. The company holding it may sell the kit and the paperwork to owners of the listed models; the modification then becomes part of that aircraft's record. The FAA's list says what was approved and for which models, not how many aircraft carry it.
Source: FAA supplemental type certificates (Dynamic Regulatory System). Register counts from the FAA register of October 20, 2026.