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

SA1308SO

Add shoulder harness to the cockpit observer seat. Held by Zantop Intl Airlines INC, which holds 8 approved modifications in all. Last revised December 11, 1981. System: cabin, seats and restraints.

What it applies to

Kind of product
Aircraft
Design holder
Lockheed Aircraft Corporation
Models
188A
Type certificate
4A22
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 7, 2026.