The Junkers Ef-126 / Ef-127 was an experimental fighter that was proposed as a response to the „Jägernotprogramm“ or „Emergency Fighter Program“ request for proposal issued by the Luftwaffe High Command.
The type featured 2 MG 151 mm canons on each side of the cockpit (similar to the He162 Salamander). While the initial design was supposed to use a single Argus As 014 pulse-jet engine, it was quickly found to be underpowered in that configuration. Various alternative propulsion options were explored, including a dual Argus As 014 configuration, a Walther 509C rocket motor, like that carried by the Me263 experimental fighter, and a single Jumo 226 pulse-jet.
The type was built utilizing a wooden for the flying surfaces with an aluminum fuselage and key structural elements. 4 Schmidding rocket boosters were arranged circumferentially around the rear fuselage in an arrangement similar to the Bachem Natter Ba 349, another design submitted to fulfill the requirements of the Emergency Fighter Program, to make it possible for the Ef-126 / Ef-127 to take off under its own power using a wheeled trolley