Why The All-Metal Mosquito Was Abandoned

The Vickers Type 432 is a British twin-engine fighter that resembles the famous de Havilland Mosquito. How did an apparent copycat plane come about?

The Tin Mosquito

The Vickers Type 432’s story started in March or April 1939, before WWII, when the British military was looking to add a new high-speed, powerful heavy fighter to its arsenal. Vickers started working on a design, but the focus shifted from a General heavy fighter to a high-altitude fighter to take out enemy bombers.

In September 1941, the Air Ministry issued another specification that followed previous specs but added a pressurized cockpit and increased the armament to 6 x 20 mm cannons, which came to be the 432 design. With this new design on the table, the original contract for two type 414s or 420s was canceled, and a new contract was drafted for two type 432s.

Similar yet Different

The Type 432 was smaller than the de Havilland Mosquito but with a gross weight of 20, 168 lbs. it was heavier than the Mosquito by about 2,000 lbs. This was because the type 432 was an all-metal construction instead of a wooden one. While the Mosquito was well known for its simplistic construction method, the 432 followed a more conventional method except for its wings.

To reduce weight and increase fuel capacity the wings were constructed in an odd and unique lobster claw structure where the bulk of the wing’s internal supports were concentrated just under the surface leaving the center of the wings hollow giving extra room for extra fuel tanks if so desired. This potential extra fuel capacity gave the 432 more range over the Mosquito. The Type 432 had a range of 1500 miles compared to the Mosquito’s 1,300 miles.

Vickers estimated the 432 would have a top speed of upwards of 435 miles per hour and a speed of 550 mph in a dive. Construction of the early prototype started in early 1942 and by the end of the same year, the first prototype was ready for testing. It finally took to the air in December 1942. However, just five days later, it was advised that the type 432 project would stop at just one prototype, and the second prototype was officially canceled.

Cancellation

As data from the flight tests came, it revealed that the Type 432 was simply unstable and difficult and demanding to fly. While they tried to remedy the issue by reworking the tail surface and slightly altering the wing shape and control surfaces, only some of these issues were somewhat mitigated and they would never end up being solved.

Also, it was built as a high-altitude fighter yet its Merlin 61 engines struggled to perform at high altitudes because of cooling issues. While its projected top speed is 435 mph, the actual top speed was over 50 miles per hour lower at 380 mph. Vickers would later receive the order to scrap the plane in late 1945.