An aircraft assembly

An aircraft assembly comprising:

• an aircraft structure;
• and
• a pipe assembly rotatably coupled to the aircraft structure by a fixture arrangement, the pipe assembly extending along a longitudinal direction, the fixture arrangement configured to restrict movement of at least a portion of the pipe assembly in the longitudinal direction relative to the aircraft structure and allow rotation of the pipe assembly relative to the aircraft structure,
• wherein the pipe assembly comprises an outer pipe section and an inner pipe section, and the inner pipe section is enveloped by the outer pipe section.