ST04798NY

AAR Engineering Services Seat Re-pitch. Held by Delta Engineering Corporation, which holds 273 approved modifications in all. Last revised April 25, 2025. System: cabin, seats and restraints.

What it applies to

Kind of product: Aircraft
Design holder: The Boeing Company; The Boeing Company; Airbus SAS; Airbus SAS; Airbus SAS; Airbus SAS; Airbus SAS; Airbus SAS; Airbus SAS; Airbus SAS; Airbus SAS; Airbus SAS; Airbus SAS; Airbus SAS; Airbus SAS; Airbus SAS; Airbus SAS; Airbus SAS; Airbus SAS; Airbus SAS; The Boeing Company; Airbus SAS; Airbus SAS; Airbus SAS; Airbus SAS; Airbus SAS; Airbus SAS; Airbus SAS; Airbus SAS; Airbus SAS; Airbus SAS; Airbus SAS
Models: 737-900ER Series, 757-200 Series, A321-111, A321-112, A321-131, A321-211, A321-212, A321-213, A321-231, A321-232, A321-251N, A321-251NX, A321-252N, A321-252NX, A321-253N, A321-253NX, A321-271N, A321-271NX, A321-272N, A321-272NX, 757-300 Series, A319-111, A319-112, A319-113, A319-114, A319-115, A319-131, A319-132, A319-133, A319-151N, A319-153N, A319-171N
Type certificates: A16WE, A2NM, A28NM, A28NM, A28NM, A28NM, A28NM, A28NM, A28NM, A28NM, A28NM, A28NM, A28NM, A28NM, A28NM, A28NM, A28NM, A28NM, A28NM, A28NM, A2NM, A28NM, A28NM, A28NM, A28NM, A28NM, A28NM, A28NM, A28NM, A28NM, A28NM, A28NM
On this site: Airbus A319 329 registered
Airbus A321 929 registered
Boeing 737 2,887 registered
Boeing 757 440 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 8, 2026.