The first of the Sigma-Class of airships, the Vectron Federation Airship Sigma (BFA Sigma) was a revolutionary design for it's time. In comparison to the traditional cigar-shaped Upsilon and Alpha class ships, the Sigma looked totally different. Perhaps the best thing it can be compared to is the Lockheed-Martin F-117 Nighthawk fighter, due to it's angled fuselage shape designed to reflect radar waves. Indeed, the Sigma looked right at home flying in formation with the odd looking jets when Deron bought two of them from the US Air Force after their retirement. The Sigma is also fitted with two massive jet turbines, which make it faster than any of the previous designs. The VFA Sigma is still in service, and it currently roams the skies above Derazuma 1.