A rib bay platform for use in an aircraft rib bay, is adjustable in length (for example it comprises two telescopically mounted sections. The platform comprises a first end configured for mounting on a stringer of the rib bay (for example by an interference fit), and a second end configured for mounting on another stringer of the rib bay (for example on feet mounted on ball-and-socket joints). A method of operating in an aircraft rib bay comprises the steps of providing a rib bay platform of adjustable length; adjusting the length of the platform; mounting the platform between the two stringers; whereby a person may then operate inside the aircraft rib bay while being supported on the platform.