A flight kit that can be retrofitted to existing navy sonobuoys. The preferred embodiment gives sonobuoys the capability of self-deployment, allowing them to be sent to a location remotely without the use of manned aircraft or recoverable unmanned air vehicles. This capability is advantageous in instances where it is desired to place a sonobuoy in an area hostile or hazardous to manned aircraft. The preferred embodiment is an attachment of a GPS navigation and control system, wings, control surfaces, and a propulsion system, onto a naval size-A sonobuoy, using the sonobuoy as the central structural load-bearing component of the assembly. The invention navigates from a launch point on a ship to a designated position, where the sonobuoy separates from the invention, using the wings' aerodynamic forces to mechanically assist in separating the sonobuoy from the flight kit. The sonobuoy and the flight kit enter the water separately to ensure no interference with the sonobuoy.