Used on blackhawk helicopter uh-60; nha engine, aircraft, turbo-shaft nsn 2840-01-070-1003. 3a 2nd end thread class stainless steel flareless tee is made from MS21905-4s; MS21905f has been superseded by sae-AS21905, nsn 4730-00-720-0317 passivate surface treated unjf 2nd end thread series
Used on ch-53 a/d/e helicopter. 3a 2nd end thread class 12 1st end thread quantity per inch fitting, tee, standard passivate surface treated unj 1st end thread series
Used on hydraulic or air system. 2a 1st end thread class 12 all ends thread quantity per inch tube normally connected with sleeve cadmium surface treated un all ends thread series