A pipe support block for an aircraft fluid system is disclosed in which the pipe support block is arranged to support a pipe on a structural member, such as a bracket. The pipe support has a first part and a second part which together form a collar. The collar has a pipe receiving bore and is configured to support a fluid pipe on the structural member. First and second fastener holes extend through both the first part and the second part. The first and second fastener holes are each arranged to receive a fastener to fasten the first and second parts to each other and to the structural member.