The story of the Westland Whirlwind is one of an aircraft of great potential, but which was let down by inadequate engines and bad timing.
First flown in 1938, the Whirlwind was a contemporary of the Spitfire and Hawker Hurricane. But it was a fighter with a lot more firepower than other fighters of the day.
A single seat, twin-engined heavy fighter, the Whirlwind featured an armament of four Hispano Suiza 20mm cannon all concentrated in the nose – a staggering amount of firepower in an aircraft of the time.
Capable of delivering a weight of fire of 600lb of explosive shells per minute the Whirlwind had the most powerful armament of any aircraft at the time of its first flight. It was also designed to be no slouch in aerial combat, with a lithe, narrow design and one of the world’s first bubble canopies. This allowed the pilot an excellent view all around, crucial for a successful dogfighter.
On paper the aircraft was world beating, and certainly the RAF hoped that its new weapon would be decisive, keeping the aircraft under wraps from the British public until 1942. It certainly looked a far finer fighter than its German equivalent, the Bf 110, a much heavier and bulkier two-man design.
But unlike its German rival, the Whirlwind had one major flaw; it’s engines were underpowered and unreliable.
Instead of the world-beating Rolls Royce Merlin – the primary aero engine for the RAF throughout most of the war – the Whirlwind used the Rolls Royce Peregrine.
The final evolution of the inter-war Kestrel engine, the Peregrine would only be produced in tiny numbers, with only 301 made. It would never get the chance to develop as all energies were focused on the Merlin.
The Whirlwind also suffered in that in came into service at the worst possible time – June 1940, the Fall of France. The RAF were scrambling to make good losses suffered in the defeat and prepare for the inevitable Battle of Britain. As the Whirlwind consumed three times the amount of precious aircraft alloy as a Spitfire attention inevitably switched to the necessity to build as many fighters as possible for the defence.
As a result only 116 were built. Despite the low numbers and reliability of their engines, the Whirlwind provided sterling service as a fighter bomber. The Peregrine worked best at low altitude and the aircrafts twin engines and tough construction, combined with heavy forward firepower and excellent visibility for the pilot, meant that the Whirlwind enjoyed some success as a ground pounder, despite its limited numbers.
Fitted with bomb racks for 250 and 500 lb bombs, Whirlwinds blasted targets all over northern France, as well proving no slouch as a low level fighter, even against dedicated single-engine fighters like the Messerschmitt Bf 109.
However, by 1943 new cannon fighters like the Typhoon were available for ground attack duties and as a result the Whirlwinds were withdrawn, flying their last missions in November of that year.
It remains one of the “what-if’s” of history to consider what may have happened had the Whirlwind been designed for the Merlin engine. It’s possible that the RAF would have kept the design in service far longer. The Merlin would have provided the aircraft with much greater potential, making it possibly a multi-role fighter of great ability that could’ve evolved and stayed capable throughout the war.