P.O. Ronald John Fyfe and the Saro Lerwick S36

In November 1938 the first three  Saro S36 Lerwicks  L7248, L7249, L7250  were assigned  as prototypes. In June 1939  four Lerwicks entered service trials with No 240 sqdn at RAF Calshot
 In December 1939 they entered There first operational service, With No 209 Sqdn (code letters WQ) at Oban Scotland. The Lerwick still had many unresolved stability problems on the water and in the air. Modifications done did not bring enough improvement, unable to maintain height on one engine, nor could it maintain a constant heading as the controls could not counter torque when only a single engine running on full throttle. The aircraft was considered unacceptable.
After only a few months of operational service the Lerwick was superseded by the Catalina PBY_5 in April 1941, Just as the last aircraft was delivered May 1941.

Originally designed by Henry Knowler of Saunders Roe, twenty one aircraft were built in total, with the sequential serial numbers L7248 Through L7268. The Lerwick had an all metal hull with anodically-treated metal covering. In side the Lerwick had a work bench and vice, a lavatory, facilities for cooking and fresh water tanks. Large lockers, fitted with padded tops and used as sleeping berths, are employed as additional stowage compartments for the numerous items of equipment. The control cabin and wardroom can be heated by air fed through ducts from the rear of the engine oil coolers. Accommodation for a first and second pilot, and for members of the crew acting as navigator, observer, engineer and wireless operator, is provided in an enclosed cabin which forms an upper deck of the hull forward of the main plane leading edge. Entrance to this cabin is gained through the roof of the wardroom, with the aid of a ladder, after entering the door on the starboard side of the hull. A door on the port side of the hull facilitates entry by members of the crew to the galley, from which compartment access to the wardroom may be gained after passing along the hull through the main aft-cabin and the mid stowage compartment. 
The pilot and co-pilot in tandem, as well as the flight engineer the rear. It had three power operated Frazer-Nash gun turrets. The bow FN7 housing a .303in (7.7mm) Vickers K gun, note some later service aircraft had doubled nose guns fitted. A  retractable dorsal FN8 mounting twin.303in (7.7mm) Browning guns and the FN4A tail turret four Browning. The bow turret could be retracted backwards to assist mooring up, similar to the Sunderland.
The bomb load consisted of either four 500lb (226kg), eight 250lb (113kg) bombs or four depth charges, were carried in two streamlined nacelles behind the engines. Bomb aiming was carried out from a position low in extreme bow, a glass screen being provided behind a sliding hatch. However due to restricted vision sighting was often carried out from the cockpit on low level approaches.
The Lerwick was powered by two 1.375hp (1,025kW) Bristol Hercules II ,14-cylinder sleeve-valve radial engines, driving three-blade de Havilland constant speed propellers. These were the world's most powerful aero engines at the time.

The first Lerwick had Hercules HE.1M engines but from L7252 Hercules MK.IIs were fitted. The final eight had Hercules IVs.