The Heinkel HE 12 was a pontoon-equipped mail plane built in Germany in 1929, designed to be launched by catapult from a liner at sea.

The concept was hit upon after Norddeutscher Lloyd (NDL) had carried a Junkers F.13 seaplane aboard the Lutzow during 1927 to provide joyrides for passengers when the liner was in port.

Heinkel designed a catapult, which NDL planned to install on its new liners, the Bremen and Europa, and an aircraft to carry the mail.

Designated He 58, the second aircraft was slightly larger overall, with increased payload and accommodation for the crew in a side-by-side open cockpit.

Power was supplied by a 370 kW (500 hp) BMW Hornet A, initially un-cowled, but later fitted with a full long-chord cowling with cooling slits in the forward face.