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

SA09906AC

Reduce maximum number of seats to 5 passenger seats with a total occupancy maximum of 6 occupants. Held by Direct-To Aviation Services INC. Last revised December 13, 2019. System: cabin, seats and restraints.

What it applies to

Kind of product
Aircraft
Design holder
Twin Commander Aircraft LLC
Models
500-A
Type certificate
6A1
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 21, 2026.