Before revision: Conformal antennas were developed in the 1980s as avionics antennas integrated into the curving skin of military aircraft , replacing conventional antenna designs which project from the aircraft surface , in order to reduce aerodynamic drag .
After revision: Conformal antennas were developed in the 1980s as avionics antennas integrated into the curving skin of military aircraft , replacing conventional antenna designs which project from the aircraft surface to reduce aerodynamic drag .