This paper describes the development of flexible heat pipe cold plate (FHPCP) technology for aircraft thermal control. Four different FHPCP's were constructed for a variety of difficult aircraft cooling problems. This included an electronics package embedded in a moving actuator, and a new digital computer installed in a fighter aircraft upgrade. In each application, a cold plate transfers the electronics' heat to the most convenient heat sink by an integrally connected flexible heat pipe. The heat pipe is flexible to allow relative motion between the package to be cooled and the heat sink. It also allows cooling to be provided to surfaces in awkward locations relative to the heat sink. The connections to the heat sink can be anything from convective air cooled fins to solid plates bolted on the aircraft's structure. The cold plates were designed to be installed in the gravity-assisted orientation, but the incorporation of a high performance wick structure allows operation in mild against-gravity conditions.