After entering service, by 1952 the type's shortcomings were becoming apparent. These included the aircraft's lack of power, especially in hot weather, and an unfortunate tendency for propellers to fail in-flight, resulting in the loss of two aircraft. The propeller problem was overcome by replacing the de Havilland variable-pitch propellers with Fairey Reed fixed-pitch propellers, modified aircraft being re-designated the DHA-3 Mk. 1F. All but the three aircraft that had crashed by that time were brought to this standard. The propeller change however did nothing to improve the type's performance. In a bid to improve lift all Mk. 1F aircraft were further modified with double slotted flaps in place of plain flaps, and were once again re-designated, this time as the DHA-3 Mk. 2.