Excerpt from a letter from R J Mitchell to Ernst Heinkel regarding this aeroplane.
"We, at Supermarine Aviation, were particularly impressed, since we have been unable to achieve such smooth lines in the aircraft that we entered in the Schneider Trophy Races. In addition to this, we recently investigated the effect that installing certain new British fighter engines would have on the He 70. We were dismayed to find that your aircraft, despite its larger measurements, is appreciably faster than our fighters. It [He 70] is indeed a triumph."