Welkin DX318
Drawbacks of the Welkin F Mk. I’s Performance
While the Westland Welkin F Mk. I was designed to be a formidable high-altitude interceptor, a number of performance drawbacks prevented it from fulfilling its intended role.
Engine and Propeller Issues: The Welkin suffered from persistent engine and propeller problems, particularly with its initial non-feathering propellers. These propellers could not be stopped from windmilling if an engine failed, leading to dangerous overspeeding that could cause engine fires. This issue resulted in numerous emergency landings during testing and development and delayed the Welkin’s entry into service. Although later production models were fitted with feathering propellers, the engine problems persisted.
Poor Maneuverability: The Welkin’s large wingspan, designed to provide lift at high altitudes, contributed to its poor maneuverability, a significant drawback for a fighter aircraft. The A&AEE’s assessment highlighted heavy and sluggish ailerons, particularly at high altitude, which resulted in a very poor roll rate. This lack of agility made the Welkin vulnerable to more nimble single-engine fighters.
Compressibility Limitations: The Welkin’s thick wing design, chosen to accommodate its pressurized cabin and fuel tanks, led to significant compressibility problems at high speeds. These issues manifested as severe control difficulties, including longitudinal pitching and lateral lurching, at speeds above Mach 0.65. This effectively imposed a low maximum dive speed, significantly limiting the Welkin’s effectiveness as an interceptor.
Weight Issues: The Welkin was consistently plagued by weight problems, which further hampered its performance. The addition of equipment and modifications, particularly the heavy pressurized cabin, contributed to an increased overall weight. This additional weight negatively impacted the Welkin’s speed, climb rate, and maneuverability.
Performance Shortfalls: Overall, the Welkin’s actual performance fell short of the initial estimates and expectations. Its speed, climb rate, and maneuverability were all inferior to what was originally anticipated, making it less competitive against existing aircraft like the de Havilland Mosquito.
These performance drawbacks, coupled with the diminishing threat from high-altitude German bombers and the emergence of superior aircraft, ultimately led to the Welkin’s cancellation and its failure to see operational service.