Looking for Otto Reder, a German aeronautical engineer born in Spain at the beginning of XX century?

Question

He was the right hand of Juan de la Cierva while working in UK in the 30's

Answer 1

Apparently he invented several things.

Abstract of GB396981 396,981. Visiblesignalling apparatus. REDER, O., 8, Lietzenburgerstrasse, Berlin. Nov. 21, 1932, No. 32891. Convention date, June 16. [Class 118 (ii).] Advertisements &e. are displayed on the under surface c of rotary supporting vanes s b in helicopter or like aeroplanes. The vanes form a disc-like screen on which display matter may be optically - projected by kinematograph or other lanterns d carried on the landing struts or mounted on a member e suspended from the aeroplane by a rope or by a telescopic tube g. In a further modification discharge or other lamps carried in or on the vanes themselves form the display, and the latter may change by moving a contact drum axially. The illumination may be timed to make the display stationary, or to make it progress in. either direction. Lamps carried by the vanes may also form a monogrammic sign controlled by a flat interchangeable contact disc or by a perforated strip winding on and off rolls contained in a contact drum through slots in the walls of which the strip passes. The drum may be arranged to be interchangeable during flight.