 As well as metal skin replacing the fabric on the fuselage, the fin was changed from having a corrugated skin to being a smooth stressed skin structure and was moved slightly aft, lengthening the rear fuselage while the engine was moved forward to maintain the center of gravity.The rudder was also changed from the rounded shape used previously to one with a roughly triangular shape with the broadest part being at the bottom to improve handling at high angles of attack.In one respect however, it was a step backwards from its immediate predecessor, the BT-14, with which it is often confused, in that the earlier straight wings were used with the result that in RCAF service, when compared to the later and more powerful Harvard II it was flown alongside, it had different handling characteristics and lower performance.