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

SA173SW

Battery relocation to inverter well and inverter relocation in compartment forward of nose. Held by Ward Intl Aircraft Service, which holds 58 approved modifications in all. Last revised April 1, 1973. System: electric propulsion.

What it applies to

Kind of product
Aircraft
Design holder
Lockheed Aircraft Corporation
Models
1329 Series
Type certificate
2A15
On this site
Lockheed 1329 6 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.