The twin-engine Saṛ Lerwick was an attractive and compact design intended to meet a medium-range maritime reconnaissance requirement, Specification R. 1/36, but was a total failure, First flown before the end of ̀938, the prototype featured twin fins and. rudders but from the outset was found to be seriously lacking m lateral stability, and displayed a determination to roll and yaw in cruising flight, making the aircraft impossible to fly 'hands off, a damning indictment for a maritime patrol aircraft. In due course a single fin and rudder was fitted, but not until this was considerably enlarged was any improvement in the handling characteristics discernible. Starting with the seventh production example, wing incidence was increased and enlarged propellers fitted to the Hercules II radiais, but the latter were found unsuitable for operating on rough water. Moreover, stalling tests showed the Lerwick to have vicious traits, the stall under alighting conditions being accompanied by sharp wing-drop. Nevertheless 21 examples were produced and the Lerwick was first delivered for service with No, 209 Squadron m December 1939 at Oban, but after the type had flown a small number of semi-operational patrols it was decided to abandon further efforts to rectify its problems. The last eight aircraft were powered by Hercules IVs and the final example was completed m November 1940; one aircraft was flown by No, 240 Squadron but was lost on 20 February of that year, and some flew with No. 4 Operational Training Unit at Invergordon.

3-View

A three-view drawing (648 x 882)