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

SA1373CE

Install third window. (PA-28-180 S/N 28-1 THRU 28-4377, PA-28-235 S/N 28-10003 THRU 28-11039). Held by Knots 2U LTD., which holds 28 approved modifications in all. Last revised May 24, 2021. System: airframe structure.

What it applies to

Kind of product
Aircraft
Design holder
The New Piper Aircraft Inc.; The New Piper Aircraft Inc.; The New Piper Aircraft Inc.; The New Piper Aircraft Inc.; The New Piper Aircraft Inc.
Models
PA-28-235, PA-28-140, PA-28-150, PA-28-180, PA-28-160
Type certificates
2A13, 2A13, 2A13, 2A13, 2A13
On this site
Piper PA-28 Cherokee, Warrior, Archer and Arrow 18,636 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.