It is necessary to provide inspection arrangements in order to facilitate prototype design of assemblies such as gas turbine engines as well as insitu testing of such assemblies. Previously endoscope type arrangements have been utilized, but the flexible or rigid stems in such endoscopes can cause fouling and snagging in use. By providing an inspection arrangement in which the inspection element is combined with a positioning tool such that the inspection element can be detached from the positioning tool through a releasable element, it is possible to avoid such snagging problems. The inspection element will be relatively self-sufficient and incorporate possibly a camera or other sensor for temperature of otherwise. The inspection element will typically incorporate a wireless link arrangement, or possibly incorporate a storage device for data such that the inspection element can be retrieved later with that data.