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

Southern Airways INC

Holds 6 approved modifications, most of them for the Martin 404. FAA spelling: Southern Airways Inc.

Approved modifications 6 · newest first

Martin 404 4Douglas DC-3 1Mcdonnell Douglas DC-9 1
1960-01-01ST399SO · Addition of underseat luggage restraint. · DC-9 Series
1960-01-01SA355SO · Whittaker 2L333021 NLG hydraulic pressure reducer valve replaced with Hydraulics Research42028180-001 valve. · 404
1960-01-01SA312SO · 32-passenger cabin interior. · DC-3 Series
1960-01-01SA325SO · Interior changes in passenger and jump seats. · 404
1960-01-01SA349SO · Hydraulic regulator change. · 404
1960-01-01ST431SO · Installation of inflatable evacuation slide. · 404

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