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

SA452SW

Installation of third window in aft cabin, left and right. Held by Apache Modification Aircraft Corporation, which holds 40 approved modifications in all. Last revised October 10, 1997. System: cabin, seats and restraints.

What it applies to

Kind of product
Aircraft
Design holder
Piper Aircraft Inc.; Piper Aircraft Inc.; Piper Aircraft Inc.; Piper Aircraft Inc.
Models
PA-23, PA-23-160, PA-23-235, PA-23-250 (Navy UO-1)
Type certificates
1A10, 1A10, 1A10, 1A10
On this site
Piper PA-23 Apache and Aztec 1,316 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 5, 2026.