A fan blade for a gas turbine engine has an aerofoil part and a root part. The first virtual device passes, to the microcontroller, commands of a first command set from any user of the host computer and preferably also commands of a second command set from only privileged users of the host computer. Further, the method includes populating a check-out screen with consumer information from the radio frequency device. Each of said structures comprises a plurality of radiation elements. The phaser further includes an inlet check valve located within the phaser structure or in very close proximity to the phaser, thereby reducing control fluid leakage.