TEST BENCHES FOR TESTING HYDRAULIC APPARATUS, HYDRAULIC ACCUMULATORS; TEST BENCHES FOR VERIFYING FLUID TIGHTNESS; ALTITUDE SIMULATION CHAMBERS-NAMELY, DECOMPRESSION CHAMBERS FOR TESTING PROGRAM HEATING, COOLING AND HUMIDITY CYCLES; AUTOMATIC RECORDERS FOR CONTROLLING AND INTEGRATING TEMPERATURE, HUMIDITY AND ALTITUDE; JET ENGINE FUEL SYSTEM TESTING BENCHES FOR TESTING PUMPS AND REGULATORS; HYDROSTATIC LEAK CHECK STANDS; "G" RESTRICTORS-NAMELY, A UNIT WHICH WARNS THE PILOT, WHEN A CRITICAL VERTICAL ACCELERATION ON THE AIRCRAFT IS REACHED, BY IMPOSING A RESISTING LOAD ON THE AIRPLANE CONTROL COLUMN; GAUGES FOR TESTING STRESS ON AIRCRAFT PARTS; MACHMETERS; MANOMETERS; PITOT TUBES; VENTURIS; AIRCRAFT DIVE SAFETY INSTRUMENTS- NAMELY, ACCELERATION INDICATORS, AND AUTOMATIC FLAP CONTROLS