The U.S. aircraft register, updated daily
Approved modifications · supplemental type certificate · current · reissued

ST00133NY-D

To install a modified Teledyne Digital Flight Data Acquisition Unit (DFDAU), P/N 2233000-3-B, in order to meet the requirements of FAR 121.344,. Held by American Airlines INC, which holds 377 approved modifications in all. Last revised September 17, 2015. System: other and general.

What it applies to

Kind of product
Aircraft
Design holder
The Boeing Company
Models
757-200 Series
Type certificate
A2NM
On this site
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 21, 2026.