The U.S. aircraft register, updated daily
Who holds what · as the FAA records the name

Mark Xii, INC

Named as the FAA publishes it on its approvals.

Holds 4 approved modifications, most of them for the Piper PA-22 Tri-Pacer and Colt. FAA spelling: Mark XII, Inc.

Approved modifications 4 · newest first

Piper PA-22 Tri-Pacer and Colt 1Cessna 185 Skywagon 1Cessna 180 Skywagon 1Cessna 172 Skyhawk 1Cessna 170 1
1965-10-18SA318WE · Torso tank 61900 or 64200. · 172 Series, 170
1965-10-18SA527WE · Torso tank 61900 or 64200. · 180 Series
1965-10-18SA417WE · Torso tank 61900 or 64200. · 185 Series
1965-10-18SA447WE · Torso tank 61900 or 64200. · PA-22 Series

Source: FAA Dynamic Regulatory System (type certificate data sheets, supplemental type certificates, parts manufacturer approvals, technical standard order authorisations). An organisation's name is as the FAA spelled it on each record; related spellings are separate pages.