An Inertial Navigation System (INS) independently measures the Position, Velocity, and Attitude (PVA) of thevehicle to navigate it towards the target. Since INS is a dead-reckoning system, it requires accurate initialization toprovide the navigation (PVA) solution. In the case of an air-launched tactical missile, the aircraft navigation system(Master INS) information is used to initialize accurately the missile INS (Slave INS). Rapid transfer alignment isneeded in today’s combat operation to converge slave INS initialization in the shortest possible time using aircraftnavigation information. The transfer alignment consists of first initializing the missile INS and establishing anavigation solution (PVA) using the missile IMU rates and accelerations, then a Kalman filter is used to, estimatethe errors between the Slave INS and Master INS. The proposed method’s simulation results show that a tacticalmissile INS can be aligned to an acceptable accuracy in a very short time based on the aircraft’s attitude information and with natural maneuvers experienced during aircraft take-off.