ST00572LA-D

Modifies the aircraft to remove one row (six seat places) of B/E Aerospace TSO C-39b seats in the forward area of economy class on our B737-300 series aircraft. With the removal of one seat row, six seat rows of B/E Aerospace economy seats aft of the class divider will be increased in pitch from 31 to 35 inches. The seat row at the Type III exit and the row forward of the Type III exit will increase in pitch from 32 to 38 inches. The modification changes the passenger capacity to 8F/112Y. The installation is in accordance with DAS-1-WE Approved United Air Lines Master Document List No. 00572 dated February 6, 200, or later FAA approved revisions. Held by United Airlines INC, which holds 520 approved modifications in all. Last revised November 30, 2011. System: cabin, seats and restraints.

What it applies to

Kind of product: Aircraft
Design holder: The Boeing Company
Models: 737-300 Series
Type certificate: A16WE
On this site: Boeing 737 2,893 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 21, 2026.