The I. Ae. 38 and 48 Delta Jets


Tests on two high speed delta wing projects, began with models that were catapulted into the sea at speeds up to 200 km/hr. By landing in water, they could usually be recovered intact. We used a pointed symmetrical airfoil, that had some interesting characteristics.

 Wind tunnel tests revealed that an eddy would form on the top of the wing, behind, and about parallel to the leading edge. The diameter of the eddy grew with increasing angle of attack, and at the same time moved to the rear. It seemed appropriate to locate the elevons in the area of the eddies, to boost their effectiveness, and maintain their response even at 30-40 angle of attack. Then we discovered that the suction of the eddy was greet enough at low speeds, to cause a negative control surface pressure!

 To further study these phenomena, a full size glider, with a prone pilot was built, complete with dummy engines. The test aircraft was towed aloft by a Ju 52, and later by a DC 3. About 150 hours of flight testing was performed with the I. Ae. 37.

 The two place supersonic I. Ae. 48 was designed and ready to be built by the end of 1959, and metal parts for the production of two I. Ae. 37 s were delivered, when we were ordered to stop the work. The reason was given as "lack of funds". The truth appears to be that the rulers of the land saw a decline in the use of delta wing fighters around the world, as the F-104 became the top fighter aircraft.

 Perhaps our project was too advanced for a developing country!