In September of 1962 the Air Force awarded North American a contract to modify a T-28A airframe with a 2,445 hp Lycoming YT-55L-9 turboprop engine with the designation of the prototype YAT-28E (NAA model 284).
To install the Lycoming engine on the T-28A the entire nose section forward of the firewall was redesigned. The new streamlined nose was longer, tapered and featured a large exhaust port on the left side of the fuselage. The propeller was replaced with an 11'6" four blade Aero Products propeller with a large pointed spinner.
The wing structure was strengthened to accomodate the hard points, increased aileron and rudder travel, better brakes and lengthened horizontal stabilizers with heightened vertical.
Three were made. The first was lost in a flat spin