S13 may refer to:
== Aviation == Beriev S-13, an abandoned Soviet reconnaissance aircraft project Fokker S-13, a German trainer Letov Š-13, a Czechoslovak fighter aircraft SIAI S.13, an Italian reconnaissance biplane Sikorsky S-13, a Russian aircraft design proposal SPAD S.XIII, a French biplane fighter
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).