The Mosquito was an unarmed bomber with a crew of two, able to carry a bigger bombload farther than a B-17. It was also a fighter-bomber and a night fighter with an eight-gun nose battery. It was the most productive photoreconnaissance aircraft of the war. A high-speed courier. A weather-recon airplane. A carrier-qualified torpedo bomber (though too late to see combat). A pathfinder and target-marker for heavy bombers. The war’s most effective extreme-low-altitude intruder. A multiengine trainer and a high-speed target tug. A decoy frequently used to convince the Luftwaffe that three or four spoof-raid Mosquitos dropping chaff were a bomber stream of Lancasters.
Mosquitos were built in 33 different variants during WWII and seven that were introduced after the war, at a time when everything else with a propeller was being shunted off to reserve and training units.
The de Havilland Mosquito was the anti-Fortress, a bomber proposed to the Royal Air Force with speed as its salvation, not guns. Many forget that the Mosquito turned out to be the first of its kind and the B-17 the last of its line. Never since have bombers truly been armed defensively. The B-29 had four remotely controlled turrets until Curtis LeMay stripped the guns from them, preferring to carry bombs and fuel rather than guns made pointless by air superiority. B-52s had a tail battery—quad .50s and then a 20mm rotary cannon—but in 1991 that station was eliminated. Neither the RAF’s Canberra nor its V-bombers had a single gun. Neither did the F-117 stealth bomber, nor the B-1 and B-2. Since the day when the Mosquito went naked, guns on a bomber have been like tits on a boar.
De Havilland began design of the Mosquito on its own. Neither Geoffrey de Havilland nor his same-named son, who became the Mosquito’s chief test pilot, had any interest in dealing with the government, for their company had thrived during the 1920s and ’30s by concentrating on the civil market, where airplanes were bought because they got a job done, not because they met some blithering bureaucrat’s specifications.
The senior de Havilland also had a champion: Air Marshal Sir Wilfred Freeman, who is often casually characterized as “a friend of de Havilland’s.” Which he certainly turned out to be, but the initial connection was that Freeman had commanded a squadron of de Havilland DH-4s during World War I and became a huge fan of that airplane. The DH-4 was one of the best single-engine bombers of the war—faster than many fighters—and remained in service with the U.S. Army Air Service as late as 1932. Freeman was confident that the de Havillands knew what they were talking about when it came to airplanes. He pushed hard enough in favor of the Mosquito that the airplane became known among its detractors as Freeman’s Folly. Lord Beaverbrook, the Crown’s aircraft production czar, three times ordered him to shut down early Mosquito manufacturing. Fortunately, Beaverbrook never put it into writing, so Freeman ignored him.
Still, it wasn’t easy for de Havilland to convince the Air Ministry that an unarmed wooden bomber faster than any contemporary fighter was the answer to Bomber Command’s needs. The obvious riposte to this too-neat theorization was that the enemy would inevitably develop faster fighters. The British could see what Germany had done in grand prix automobile racing and had no illusions about the country’s technological prowess. This proved to be true to a degree when advanced versions of the Fw-190 and the nitrous oxide–boosted Me-410 became operational, and absolutely true when the Me-262 twin-engine jet flew. But nobody had anticipated the mid-1940s plateau of propeller effectiveness and compressibility problems that would limit conventional fighters to speeds roughly equivalent to the Mosquito’s no matter how extreme their horsepower. The Mosquito was fast in 1940 and remained fast in 1945.
In April 1940, U.S. Army Air Forces General Hap Arnold brought to the U.S. a complete set of Mosquito blueprints, which were sent to five American aircraft manufacturers for comment. All were contemptuous of the British design, none more so than Beechcraft, which reported back, “This airplane has sacrificed serviceability, structural strength, ease of construction and flying characteristics in an attempt to use construction material that is not suitable for the manufacture of efficient airplanes.” Beech couldn’t have gotten it more wrong if they had tried.
Mosquitos were internally coated with traditional marine varnishes, not nearly as waterproof as modern polyurethane coatings. So there were cases of Mosquito structural failures caused by simple wood rot—some among de Havilland of Canada–built airplanes, which were sometimes found to suffer from poorer workmanship and lower quality-control standards. A few Mosquitos—a total of 212—were also built in Australia, but that country had even bigger problems, with only a tiny cadre of aviation engineers and technicians to depend upon. The first 50 Australian-built Mosquito wings were so badly glued they had to be rebuilt.
The Mosquito was not an easy airplane to fly. As combat aircraft historian Bill Sweetman wrote in his book Mosquito, it was “a slightly nervous thoroughbred which could perform impressive feats in the hands of the courageous and competent…but would occasionally deal out a kick or a bite.” Its power-to-weight ratio and wing loading were both high, and its Vmc—the speed that needs to be maintained to assure rudder effectiveness with one engine feathered and the other running at full power—was, depending on load, an eye-watering 172 mph or more, probably the highest of any WWII twin. The much-maligned B-26 Marauder had a Vmc of about 160 mph.
The biggest gun ever mounted in a Mosquito was a 57mm cannon called the Molins gun. It had a 25-round, rapid-fire ammunition feed designed and built by Molins, a formerly Cuban company that had become the world’s largest manufacturer of cigarette-making and -packaging equipment. The 75mm gun mounted in hardnose B-25G and H Mitchells was obviously larger, but it had to be manually reloaded by the bomber’s navigator, so its rate of fire was about one-sixth that of the Molins gun. Many doubted that the Mosquito’s structure could withstand the Molins’ recoil, but de Havilland needed just one day—the time it took the factory to saw the nose off a crashed Mosquito, mount the 12-foot-long gun and test-fire it—to prove them wrong. The barrel recoiled 18 inches and hosed out a gout of flame 15 to 20 feet long, but the wooden airframe was flexible enough to dampen the shock.
Mosquitos that carried the Molins were called “Tsetses,” after the deadly African fly. Their specialty was sub-hunting in the Bay of Biscay. The bay was so shallow that the German subs had to dash across while surfaced, and Tsetses picked off enough of them that soon the subs could only travel at night. Tsetses also destroyed more than a few Luftwaffe aircraft, and the effect of a 57mm projectile on, say, a Ju-88 was devastating.
Another unusual weapon was the Highball, a Mosquito-size version of Barnes Wallis’ famous Dambuster bouncing bomb. It was developed for use against Tirpitz, the German battleship hidden away in a Norwegian fjord. The Highball was to be spun up in flight—two were carried in the open bomb bay of each Mosquito—by power from a ram-air turbine, which must have been one of the first-ever uses of a RAT. Highballs would be dropped at very low altitude to bounce over the torpedo netting that protected Tirpitz and then crawl down the hull to explode well below the waterline.
WWII Bouncing Bomb Tests at Ashley Walk, New Forest 1943 Code named ‘Highball’. A type of ‘Bouncing Bomb’ designed by Dr Barnes Wallis. Spherical (ball like) in shape it was designed to be used against large ships. Two of these could be carried and deployed by a single De Havilland Mosquito aircraft. In 1943 the Ashley Walk Bombing Range in the north of the New Forest near Godshill was used as a test and training range for inert versions of the bomb. A target, No.3 Wall Target, was specifically constructed on the range for these tests.
Barnes Neville Wallis was born the son of a doctor on 26 September 1887 in Ripley, Derbyshire. Wallis worked first at a marine engineering firm and in 1913 he moved to Vickers, where he designed airships, including the R100. In 1930, Wallis transferred to working on aircraft. His achievements included the first use of geodesic design in engineering, which was used in his development of the Wellesley and Wellington bombers. When World War Two began in 1939, Wallis was assistant chief designer at Vickers’ aviation section.
In February 1943, Wallis revealed his idea for air attacks on dams in Germany. He had developed a drum-shaped, rotating bomb that would bounce over the water, roll down the dam’s wall and explode at its base. The bomb was codenamed ‘Upkeep’. Impressed with the concept, the chief of the air staff, ordered Wallis to prepare the bombs for an attack on the Möhne, Eder and Sorpe dams in the important German industrial region of the Ruhr.
Operation Chastise, the ‘Dambusters Raid’, was carried out on the night of 16 – 17 May 1943 by the specially created 617 Squadron of the Royal Air Force, led by Guy Gibson. Two of the dams – the Mohne and Eder – were breached, leading to serious flooding in the surrounding area, although industrial production was not significantly affected, and 8 of the 19 bombers which took part were lost. The most significant result was the hugely positive effect on Allied morale.
A bouncing bomb is a bomb designed to bounce to a target across water in a calculated manner to avoid obstacles such as torpedo nets, and to allow both the bomb’s speed on arrival at the target and the timing of its detonation to be pre-determined, in a similar fashion to a regular naval depth charge.
The inventor of the first such bomb was the British engineer Barnes Wallis, whose “Upkeep” bouncing bomb was used in the RAF’s Operation Chastise of May 1943 to bounce into German dams and explode under water, with effect similar to the underground detonation of the Grand Slam and Tallboy earthquake bombs, both of which he also invented.
The success of the operation to destroy a number of reservoirs in Germany which became known as Operation Chastise, the RAF had a very special method. The specialty of this operation began with the use of selected squadrons, the use of specially modified Avro Lancaster bombers. The crew was selected from various countries (Canada, US, New Zealand, UK), the tactics that were deployed were also specialized, and used specially designed bombs. As planned, the attack would be carried out at night during the full moon when the lake water was at its peak.
The Bouncing Bomb – Operation Chastise
On the night of 16-17 May 1943, Wing Commander Guy Gibson led 617 Squadron of the Royal Air Force on an audacious bombing raid to destroy three dams in the Ruhr valley, the industrial heartland of Germany. The mission was codenamed Operation ‘Chastise’. The dams were fiercely protected. Torpedo nets in the water stopped underwater attacks and anti-aircraft guns defended them against enemy bombers. But 617 Squadron had a secret weapon: the ‘bouncing bomb’.
Operation Chastise and Dambusters – Germany