The D.H. Diana and Dragon: Details of the Four‐Engined D.H. 86 and the Twin‐Engined D.H. 89

THE main planes of the four‐engined D.H.86, Diana, have an aspect ratio of 12·3 with an exceptionally heavy taper in chord to the tips. The aerofoil section used is a modified R.A.F. 34. Both planes are swept back 4 ft. 9 in. and are set at a dihedral angle of 3 deg. The gap is 6 ft. 4·8 in., and there is a small forward stagger of 8·5 in. The interplane bracing is unusual. There are two steel tube struts on each side where the outer engines are mounted and a single I‐section strut, built up of steel sheet with an outer fairing, near the wing tip. The lift and anti‐life wires, which are duplicated, are in the plane of the front spars only.