Hamburger Flugzeugbau Ha 137
…Flugzeugbau, not even two years old at this point, had a truly capable design team of its own. One Ha 137 single-seat prototype competed against the Henschel Hs 123 at Rechlin. Hamburger had already designed a biplane trainer of no particular distinction, the Ha 135 under its first designer, Reinhold Mewes. Mewes…