Introduction The investigation involves, briefly, the mounting of a wing of 45' sweep-back in a dorsal position on the fuselage of 'Lancaster' P.A.474 such that wing incidence will be variable in flight over a 20 range, i.e. ± 100. A ‘partial chord’ technique for swept wings has been established by the College using a similar wing mounting configuration on an Avro 'Anson' Aircraft and this technique has been applied to the current investigation.