EntityQ237581· pop 6S51Sign in to saveS51 may refer to:Article2 sectionsContentsAircraftOther usesS51 may refer to:== Aircraft == Blériot-SPAD S.51, a French biplane fighter SIAI S.51, an Italian racing flying boat Sikorsky S-51, an American helicopterRead full article (3 paragraphs)Connectionslist of S-phrasesEntitySikorsky S-51 DragonflyEntityCategoriesLetter–number combination disambiguation pages