WITH SINGLE-SPAR WING. The Italian Bergamaschi P.S.1 monoplane is a four-seater with a Fiat A.70 200 h.p. radial. A single spar, manufactured from steel tubes, is used for the wing. A top speed of 161 m.p.h. is claimed and the stalling speed is given as 37 m.p.h. The undercarriage is retractile.