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

SA1728SO

Replace existing nickel-cadmium batteries with Teledyne Battery Products G-6381E and G-6381ES. Held by Teledyne Battery Products, which holds 56 approved modifications in all. Last revised May 4, 2001. System: electrical power.

What it applies to

Kind of product
Aircraft
Design holder
Piper Aircraft Inc.; Piper Aircraft Inc.; Piper Aircraft Inc.; Piper Aircraft Inc.; Piper Aircraft Inc.
Models
PA-31T, PA-31T1, PA-31T2, PA-42-720, PA-42
Type certificates
A8EA, A8EA, A8EA, A23SO, A23SO
On this site
Piper PA-31 Navajo and Chieftain 935 registered
Piper PA-42 59 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.