BEA Gets the Trident and More

BEA Trident 1C in the original delivery colors
(Wikipedia)

A while back I had posted about a short lived proposal between Boeing and De Havilland for the former company to license build the DH.121 Trident in the United States. That was but one of many twists and turns in the rivalry between the DH.121 Trident and the Boeing 727. Building on the success of the 707 family, Boeing next launched the 727-100 for the short-haul market and like the Trident, was a T-tailed three-engined aircraft built broadly to the same specifications. But having cut its teeth on the commercial market successfully with the 707, the 727 quickly gained fame as a technological and aerodynamic success that could fly near its limiting Mach number at 37,000 feet smoothly yet possess the high-lift wings to allow it to land at speeds as low as 100mph and serve short airfields and smaller communities. The Trident, on the other hand, wasn't designed for short field performance and had the nickname "Gripper" by its pilots on account of its long takeoff run. Its engines weren't as powerful as the new Pratt & Whitney JT8Ds on the 727 and De Havilland actually pitched the Trident as an "economy aircraft" on contrast with the hot rod performance of the 727. 

De Havilland originally had designed a larger aircraft that could have boasted the seat-mile economics of the 727, but as the aircraft was being designed to British European Airways (BEA) requirements for European services, BEA wanted a smaller aircraft and the first version of the Trident carried only 78 passengers. It ended up having to compete with the successful Caravelle in capacity below the Trident and the Boeing 727 on the top end of the capacity segment. De Havilland even tried to pitch a version of the Trident to American Airlines which at that point hadn't made up its mind yet on the 727 whereas Eastern and United had already committed their launch orders. But in August 1961 American followed United and Eastern in ordering 25 727-100s in a crushing blow to the British sales effort. And to add insult to injury, De Havilland was having a difficult time pleasing BEA, its planned primary customer as BEA kept changing its requirements and asking for changes to the Trident design. Once changed and approved for production, BEA would come back with another set of changes resulting in a small production block with several different variants to suit BEA's wishes. Some in the De Havilland program felt that BEA was trying to sabotage the Trident with its requests while Boeing turned out 727s in only two basic versions by the hundreds. Even later versions of the Trident with higher-powered Rolls-Royce Spey engines and longer fuselages to carry more passengers failed to dent the 727 worldwide sales juggernaut as order after order bypassed the Trident in favor of the 727.

BEA Trident Two- the aircraft was progressively improved
(Wikipedia)

On 22 November 1965 the British Minister of Aviation, John Stonehouse, affirmed the government's support for the longer ranged Trident Two version which interested BEA more than the Trident 1 versions (despite the Trident 1 being built to BEA's own specifications). Parliament even approved funding to launch the Trident Two program. But in the following year, the head of BEA, Sir Anthony Milward, not only said BEA needed less capacity than the Trident Two, but that he had also had discussions with Boeing and Douglas. Some historians feel that Milward was engaged in brinkmanship with the UK government to get the Tridents as the lowest price possible. Milward himself stated publicly that "BEA wanted to buy British, but that it could not afford to buy British if the product was not the best on the market." De Havilland then went on to create the Trident Three, BAC offered a stretched version of the BAC One-Eleven and even Vickers proposed a short-haul version of the VC-10. But the 727-200, 737-200, and the DC-9 were also on BEA's table for discussion. 

With the election of a new Labour Party government keen on supporting British industry, Milward warned that "If a British aircraft was available to do this job at the right price we'd be delighted. At the moment there are no signs that such a British aircraft is available." It was well-known that BEA had asked for approval to purchase 35 727-200s and 737-200s. De Havilland was astonished that after creating larger versions of the Trident, BEA said the market had an overcapacity, but then turned around and wanted order larger American aircraft. 

BEA Trident Three in British European's final livery
(Wikipedia)

Already the Labour government was under fire for campaigning to support British industry but had already ordered the McDonnell Douglas F-4 Phantom, the Lockheed C-130 Hercules, and the General Dynamics F-111 to replace the canceled TSR.2. Despite BEA's desires for American jets, the political winds in London of the day dictated that they had to buy British, no matter what. BAC offered the Two-Eleven successor design to the One-Eleven, but BAC required millions of dollars in launch aid to start work on the Two-Eleven. Eventually the Two-Eleven project had to be abandoned and support had to be shifted over to the penultimate version of the Trident, the Trident Three. BEA was directed to purchase this aircraft and Milward made plain that the Trident Three was BEA's third choice and if it were compelled to operate the Trident Three, then BEA should receive compensation from the British government for not getting the more economical 727-200s and 737-200s they wanted. 

The new Minister of Aviation, John Mulley, found himself backed into a corner by BEA and the British government. BEA had to buy the Trident Three at the direction of the government but BEA wanted compensation to offset the higher operating economics of operating the Trident Three. 

On 13 March 1968, BEA announced it was ordering 26 Trident Threes with options for 10 more. Four months later, the government announced what was called the "Mulley Pledge"- approximately US$50 million was transferred to BEA and was calculated to be the cost difference between the higher seat-mile costs of the Trident Three versus the 727-200. And additional 50% of that initial transfer would be made available later to BEA, fufilling the Labour government's pledge to support the British aircraft industry. 

Source: Flight of the Titans: Boeing, Airbus, and the Battle for the Future of Air Travel by Kenny Kemp. Virgin Books, 2006, p65-74.

Jaki Jakimiuk and the PZL Fighters: The Roots of the De Havilland Beaver

Jaki Jakimiuk

In telling the story of the development of the De Havilland Canada Beaver, there were many brilliant minds at De Havilland Canada and no story of the development of any aircraft can be fully told without looking at previous design influences. Often in aviation history, military aircraft have design influences on civilian aircraft- sometimes the design lineage is obvious, like the pathway from the Boeing B-29 Superfortress to the Boeing 377 Stratocruiser. Sometimes the path of development is parallel but intertwined, like that of the Lockheed C-5 Galaxy and the Boeing 747. And sometimes individual designers bring their experience to a project that leaves their stamp on it- like Jack Northrop's influence on Douglas designs from his time working for Donald Douglas. In the case of the De Havilland Canada Beaver, the experience of the company's chief design engineer, a gregarious Polish emigre named Wsiewolod "Jaki" Jakimiuk and his prior work before the Second World War with the PZL series of fighters, would, combined with the talents of his colleagues that the De Havilland's Downsview facility, create one of the greatest bush aircraft of the skies. 

Zygmunt Pulawski

The story begins with the Polish aeronautical engineer Zygmunt Pulawski. Born in 1901, Pulawski made a name for himself as a student at the Warsaw University of Technology designing and building his own gliders. Graduating in 1925, he went to work in France for Breguet, gaining valuable experience in aircraft design and construction. After two years he returned to Poland, became a pilot and by 1927 was the chief designer at the Central Aviation Workshops in Warsaw which was soon reorganized into PZL (the Polish abbreviation for State Aviation Works). It was in that capacity he submitted the winning design for a 1928 requirement from the Polish military for a new fighter aircraft, the PZL P.1. At PZL, Pulawski pushed his team to all-metal construction at a time when many fighter aircraft were still biplanes with fabric and wood components. At the time of its first flight in 1929, the P.1 was one of the most advanced fighter designs in the world with its gull winged monoplane wing, slim nose with a Hispano-Suiza V-12 engine and a finely corrugated metal skin that would be imitated by many contemporary designs. Pulawski's gull wing was so that the wing roots met the fuselage at the most aerodynamically optimum 90-degree angle and the cylinder heads of the V-12 engine matched the angle of the wing roots, giving the pilot excellent forward visibility compared to contemporary fighter designs. 

Model box art showing the P.1 configuration

The P.1 was showcased throughout Europe and even was demonstrated at the 1932 Cleveland Air Races in the United States. At a 1930 fighter competition in Bucharest, Romania, the P.1 made an excellent showing against contemporary types which included the Bristol Bulldog and the Dewoitine. The P.1, however, remained only a prototype as the Polish military preferred the Bristol Mercury radial engine which was being license built in Poland at the time. Pulawski, however, developed the P.1 design further with more powerful V-12 powered aircraft, the P.8, which first flew in August 1931. However, the two P.8 prototypes had cooling issues in the engine, but more importantly as a setback, Pulawski had perished in a crash on 31 March 1931. Lacking a strong proponent for streamlined in-line engine designs, the P.8 was canceled by the Polish government. 

The radial engine-powered P.6

At the time that the Polish military pushed for the incorporation of the Bristol Mercury radial engine into the P.1 design, Pulawski's assistant engineer was Jaki Jakimiuk. Prior to Pulawski's death, it was decided to forgo the Bristol Mercury engine and go with the more powerful nine-cylinder Bristol Jupiter engine with 500 horsepower which was also built under licence in Poland as well. The P.6 first flew in August 1930 and had a new, more streamlined fuselage and empennage and a Townend ring to improve the airflow over the protruding radial heads in the nose. Interestingly, the design of the DHC Beaver would go through the same transition, originally envisioned with an inline engine in a slim nose but ended up with a more robust radial engine. Like the P.1, the P.6 elicited quite a bit of interest in aeronautical circles worldwide- it was demonstrated at the 1931 Paris Air Show and it also won the 1931 National Air Races in the United States which were hosted by Cleveland, Ohio, that year. The P.6 also remained a prototype as a more refined design, the P.7, succeeded it. 

PZL P.7 in Polish Air Force markings

The P.7 was a P.6 with a more powerful variant of the Bristol Jupiter radial that had now had 520 horsepower, but more importantly, featured a supercharger for improved performance at altitudes over 10,000 feet. In addition, some of the aerodynamic refinements to the wings that were used on the P.8 were incorporated into the P.7. The Townend ring used on the P.6 was increased in chord for improved aerodynamics. One interesting feature of the design is that the main fuselage fuel tank which was located behind the engine but ahead of the cockpit, could jettisoned in case of an engine fire. The P.7 went into production and became operational in 1933 at which time the Polish Air Force became the first air force in the world to be completely equipped with all-metal monocoque fighter aircraft. By this time Jaki Jakimiuk had succeeded Pulawski upon his death and the PZL works in Warsaw were hosting technical delegations from aircraft companies throughout Europe. Jakimiuk himself often hosted the delegations who came to study PZL's techniques and discuss Jakimiuk's design philosophy. In 1937, a delegation from De Havilland came from the UK to meet with Jakimiuk for an exchange of ideas. At the time, De Havilland was working on its first all-metal airliner, the DH.95 Flamingo. One of the engineers doing an internship on the Flamingo project was Dick Hiscocks, a graduate of the University of Toronto who would eventually join Jakimiuk's team at De Havilland Canada as its aerodynamicist.

The PZL P.11, Poland's primary fighter at the outbreak of the war

At the outbreak of the Second World War with the invasion of Poland in September 1939, three Polish Air Force squadrons still flew the P.7- though more maneuverable than any Luftwaffe fighter and able to operated from grass fields with a takeoff run under 500 feet, the P.7s were simply outclassed by the Luftwaffe's Messerschmitt Bf 109s. But in 1931, the war was far in the future and Jakimiuk and his PZL team refined the P.7 further to create the P.11 which first flew in August 1931. Even before the P.11 was launched into production, Romania showed interest in the design and had arranged to license-build it as the IAR P.11 (the Romanians even incorporated the P.11's tail unit in their later IAR 80 fighter aircraft design). The P.11 used an even more powerful engine than the P.7, a 800-horsepower Bristol Mercury IV, combined with an even more robust structure based on the P.7 design. The first P.11s became operational with the Polish Air Force in 1935 as the primary fighter. 

Model box art of the P.24 in Royal Hellenic Air Force colors

Buoyed by the success of the P.11 and its export to Romania, Jakimiuk developed the P.11 further into a variant intended for export, the P.24. Since the license for the Bristol radial engines prohibited export, the P.24 was based on the P.11 but incorporated a 900-horsepower French Gnome-Rhône Mistral radial engine which was a fourteen-cylinder two-row engine. In addition, the P.24 had a fully-enclosed cockpit and heavier armament that could include two 20mm cannons. Greece took delivery of 36 aircraft, Turkey took 60 (in fact the world's only surviving P.24 is in a Turkish museum), Bulgaria took 36 and Romania got 50 with 44 of them license-built by IAR. The P.24's performance was quite a leap from the P.11 thanks to its more powerful engine and the first variable-pitch three bladed propeller fitted to a PZL fighter design. Turkey's P.24s were flown until the late 1940s as training aircraft, some getting retrofitted with the Pratt and Whitney Twin Wasp engines used on the Douglas DC-3. Romania's P.24s protected the Ploesti oil installations at the start of Operation Barbarossa and flew ground attack missions until 1942. The Royal Hellenic Air Force was the only air arm to use the P.24 as its primary fighter type and it gave a good account for itself against the numerically superior Regia Aeronautica during the Italian push in Albania. By the time of the German invasion in April 1941, though, only five P.24s remained. 

Model box art of the P.50

Given the leap in performance of the P.24, you might be asking yourself why the Polish Air Force never operated it and stuck with the P.11. When the P.11 became operational in 1935, that was around the same time that the prototypes of the Messerschmitt Bf 109 (1935) and the Supermarine Spitfire (1936) first flew. It was pretty obvious to the Polish military command that the P.11s were quickly going to be come obsolete, so Jakimiuk broke from PZL tradition to design a much more modern fighter- a low wing monoplane fighter with an enclosed cockpit and retractable undercarriage, the P.50 Jastrząb or Hawk- it looked a lot like the Curtiss P-36 Hawk, though this is purely coincidental given that common problems in aviation design result in common solutions. Again using the Bristol Mercury engine, Jakimiuk's design was enthusiastically accepted by the Polish Air Force and ordered into production in 1937. The 800-horsepower Bristol Mercury VIII engine was ordered direct from the UK until license production could get underway in Poland. The second prototype P.50 would have an even more powerful engine, the Bristol Taurus with 1,150 horsepower with plans for a P.50 export variant with French Gnome-Rhône engines. The first flight was made in February 1939. The following prototypes and production standard aircraft were planned to have a cut down rear fuselage to improve rearward visibility during air combat. 

At the end of August 1939 on the eve of the German invasion, only the unarmed P.50 prototype was flying. The second prototype P.50 still had not received its Taurus engine and the third prototype was about 80% complete. In addition, airframe sections for four more P.50s were under construction. Poland fell to the Nazi onslaught in two days with the P.50s being captured and studied before being scrapped in 1940. The sole P.50 prototype was flown out in an attempt to escape, but ran out of fuel and crashed. Jakimiuk and his family managed to escape Poland during the invasion and his prior contacts with De Havilland proved fruitful as they arranged for him to work at their Canada subsidiary at Downsview north of Toronto. Rather amusingly, Jakimiuk, his family, and a team of engineers from PZL that he brought with him, were denied a permanent visa by the Canadian government as Ottawa bureaucrats demanded to know who was covering the Poles' travel costs from the UK to Canada. De Havilland guaranteed the travel costs for Jakimiuk and his family and his team of engineers as a gesture of thanks for the their advice on the DH.95 Flamingo transport back in 1937. In all, De Havilland covered the costs of travel and relocation for forty PZL engineers and their families to Canada to work at the Downsview facility. Many of Jakimiuk's colleagues would go on to to have illustrious careers in both the Canadian and American aerospace industry for years to come after the war. As for Jaki Jakimiuk, by the end of the Second World War he would become De Havilland Canada's chief designer and his experience with the PZL fighter line would prove indispensable as DHC made the transition from wartime production to peacetime civilian aircraft designs. 

But that's a story for a future blog article!

Source: Immortal Beaver: The World's Greatest Bush Plane by Sean Rossiter. Douglas & McIntyre Books, 1996, pp 17-23. Photos: Wikipedia, Wings Palette, Internet Modeler

A Watershed Moment in Close Air Support: The 1927 Battle of Ocotal

Major Ross Rowell, USMC

Less than a year had elapsed in Nicaragua since the last civil war and American intervention (1912-1925) ended when liberal and conservative factions in the unity government broke into open rebellion on 2 May 1926 with conservative factions representing the Managua government. On 24 January 1927, the 400 Marines arrived in-country at the request of the government as events proved beyond Managua's ability to control. Accompanying the initial group of Marines was the Marine Observation Squadron VO-1M, led by Major Ross Rowell. In the years following World War I, Marine aviation was very much a lean force, so much so that Marine aviators like Rowell had to be temporarily assigned to the Army to get flight training. Rowell's tour of duty with the US Army began in 1923 at Kelly Field in San Antonio, Texas. There he was assigned to the 3rd Attack Group, an Army squadron that had been established in 1921 to specialize in ground attack. The unit had experimented with a variety of aircraft during this period which were to have been designed for the role of ground attack (and distinct from long-range bombing) on the battlefield, but most designs were wholly inadequate for the roles envisioned by the Army unit. The unit ended up experimenting with the De Havilland DH-4B for ground attack as the aircraft was plentiful, available, and had been used by the British in the ground attack role in the First World War. Using the DH-4B, the unit experimented with dive bombing, which to be more accurate was more glide bombing- the distinction being that glide bombing involved descents of about 45 degrees while dive bombing was quite a bit steeper, approaching 70 degree or more. British experience in the First World War had shown that steep attacks greater than 45 degrees were needed to attack ground positions and while ground attack in the First World War never proved decisive, the seeds of the idea had been planted and were being sown further by the unit that Major Ross Rowell was assigned to. Their DH-4Bs were modified with underwing racks that could hold 10 small bombs. The aircraft was less than suitable for the role and the unit's work had concluded that attacking aircraft would be exposed to hostile fire during its attack that the mission would be of little use. 

Despite the inadequacy of the DH-4 biplane, Rowell held the opposite view as a result of his time with the Army in San Antonio. Given the number of interventions the Marines were conducting in the 1920s, Rowell was convinced that an aircraft making a steep glide or dive attack would be useful for close air support in the small guerrilla wars that the Marine Corps were being committed to throughout Latin America during the interwar period. Upon his return to the Marines from his tour with the Army, Rowell was given command of Marine Observation Squadron One (VO-1M) based at North Island in San Diego. VO-1M had just returned from the Marine intervention in Santo Domingo and based on their experience there, was designated the aviation asset to accompany Marine expeditionary forces being sent overseas. As such, Rowell instructed the pilots of VO-1M in glide and dive bombing based on his experiences with the Army's 3rd Attack Group in Texas. He relentlessly trained his men against simulated ground targets as well as seaborne targets. In February 1927, VO-1M was given orders to deploy to Nicaragua to support the Marines there that landed the previous month. By the end of February, Rowell had the unit's DH-4B biplanes flying a variety of missions ranging from observation and reconnaissance, shuttling messages amongst the various Marine garrisons in the country, and supporting assaults against the rebels who called themselves Sandinistas after their leader, Augusto Cesar Sandino. Prior to the arrival of VO-1M, most air missions during the civil war were flown by the Nicaraguan Air Service which didn't amount to much- two converted civilian Laird Swallow biplanes flown by mercenary pilots that dropped dynamite on the Sandinistas. Needless to say, it wasn't terribly effective and for the most part, the Sandinistas ignored the aircraft until VO-1M arrived. 

Marine DH-4B. Note the Ace of Spades logo of VO-1M. 

On 17 July 1927, a large Sandinista force of 800 men attacked the small Marine outpost at Ocotal near the Honduran border about 125 miles from the capital, Managua. Defending the outpost were 37 Marines and less than 50 Nicaraguan National Guard. The attack opened at 3:00am and it wasn't until 10:15am in the morning that the Marine HQ in Managua became aware of the attack after a Marine patrol overflew Ocotal and saw the gunfire. Major Rowell mustered five DH-4Bs which were crewed by two and bombed up to fly to Ocotal. Since there was no other Marine force in the area that could be delivered to the area in time on account of distance and Nicaragua's primitive transportation network, it was Marine air or nothing to save the garrison at Ocotal. Arriving over the garrison, Rowell circled the area to assess the situation. At the time, radios were supplied to VO-1M, but their were so heavy given the technology of the time, it was easier to remove the radios and trade that weight for fuel and bombs. The beleaguered Marine garrison laid out colored panels to give Rowell and his pilots indications of where the Sandinistas were located. Being 125 miles from their base in Managua, the fuel situation didn't lend itself to extended loitering by the DH-4Bs and to make matters worse, thunderstorms were approaching the area. Rowell organized his pilots into a bombing column that was single file and he made the first diving attack from 1500 feet, released a some bombs and then pulled out at 600 feet with the other four aircraft in the column following suit against targets he'd marked with his own bombs. Since the Sandinistas' previous exposure to air attacks were minimal, the Marine attacks drew little if any ground fire. In fact, the Sandinistas weren't even taking cover. Rowell astutely realized this fact and had his men fly lower for greater accuracy, diving from only 1000 feet and pulling out at only 300 feet. During their dives, the pilots fired the forward gun to add to the firepower and in the pull out, the observer in the rear seat would strafe as well with their trainable gun, effectively suppressing any potential ground fire. The Sandinista attack on the garrrison was broken as they retreated in the countryside taking approximately 25% casualties from the air attacks. Major Rowell would earn the Distinguished Flying Cross for leading the attack to save the Marine garrison at Ocotal.

It was a watershed moment in the history of military air power and close air support- the 1927 Battle of Ocotal was the first time that an ground unit facing a numerically superior enemy was saved solely by aerial intervention. It was a lesson not lost by the Marines in particular. During the time period and well into the Second World War, Army doctrine manuals discouraged close air support out of a fear of friendly fire casualties while the Marine Corps were quite the opposite in seeing air support as an integral part of ground force operations. It was also the first time that steep diving attacks were used in combat effectively. During his time at North Island in San Diego, Rowell had made friends with a number of naval aviators of the Pacific Fleet would were soon to make their own mark on the history of military aviation with their use of dive bombing. But as always, that will be the subject of a future post on this blog!

Historical aside: VO-1M was formed in 1919 as First Division, Squadron 1. Following the intervention in Santo Domingo, the squadron was redesignated VO-1M. Prior to the Battle of Ocotal, the squadron was redesignated again as VO-8M. In 1934, as part of the reorganization of Marine aviation, the unit was reorganized and was routinely sent to sea aboard aircraft carriers to participate in exercises. In 1941 the unit was moved to Hawaii with their first monoplane, the Vought SB2U Vindicator, along with a redesignation to VMSB-231 (Marine Scout and Bombing Squadron 231) and was embarked on the USS Lexington when Pearl Harbor was attacked. In 1942 the squadron transitioned to the Douglas SBD Dauntless and participated in actions at Guadalcanal and later in the war got the Vought F4U Corsair for the Marshall Islands campaign. They were deactivated in 1962 after long serving as a Marine reserve unit. They were brought back in 1973 to become an AV-8A Harrier unit and fly the AV-8B Harrier II today as VMA-231 "Ace of Spades"- the Ace of Spades logo used on VO-1M's DH-4s in Nicaragua are still the unit emblem today.

Source: Strike From the Sky: The History of Battlefield Air Attack, 1911-1945 by Richard P. Hallion. Smithsonian History of Aviation Series, Smithsonian Institution, 1989, pp 71-75. Photos: USMC, Wikipedia.

The Short and Deadly Career of the De Havilland Swallow

Evolution of the Comet from mailplane to jetliner

The Allies reaped a technological windfall with the unconditional surrender of Nazi Germany in May 1945. Both the United States and Great Britain in particular found that their wartime studies of future jet aircraft experienced quantum leaps in performance with the incorporation of the aeronautical knowledge of the personnel technical documents, and aircraft of the Third Reich. During the final half of the Second World War, Britain grappled with the future of passenger flight with the Brabazon Committee's deliberations on the future of commercial aviation. Of the five designs put forth by the Committee, the most advanced was the Type IV design for a jet-powered 100-passenger design. This aircraft would become the De Havilland DH.106 Comet- but the DH.106 started out as a very small, modest adaptation of the Vampire jet fighter as jet-powered mailplane with a six-seat passenger compartment. But with the input of the Brabazon Committee, the DH.106 evolved into a substantially larger aircraft that at one point was a tailless design before taking on the shape now familiar as the Comet. 

TG283, the low-speed DH.108 aircraft

The British were particularly interested in the Messerschmitt Me 163 Komet rocket-powered point interceptor- it was fast, had modestly swept wings, was tailless and was known to have good flying characteristics. As a result of their evaluation of the Komet, the government issued the E.18/45 requirement which was awarded to De Havilland for the construction of two small jet-powered research aircraft to study swept wings and the tailless configuration. Designed by De Havilland engineer Ronald Bishop, what was designated the DH.108 used the fuselage of the De Havilland Vampire jet fighter which was stretched and streamlined combined with a new swept vertical fin and new swept wings. This served to save time and effort and like the Vampire jet fighter, the DH.108 had wing root intakes. Unofficially named "Swallow", the two prototypes received the RAF serials TG283 and TG306. TG283 had a 43-degree swept wing and was intended for low speed testing while TG306 had a 45-degree wing and was assigned to high-speed transonic testing. Initial wind tunnel studies suggested that the Swallow would have lousy stall characteristics, so the first of the two to fly, the low-speed assigned TG283, had fixed wing slats and anti-spin parachutes in fairings on the wingtips. It made its first flight on 15 May 1946 and TG306, the high-speed Swallow, made its first flight a month later and had automatic wing slats but no anti-spin parachutes.

VW120, the third DH.108 Swallow that broke the sound barrier in 1948

The test pilot for the DH.108 was the chief test pilot for the company, Geoffrey De Havilland, Jr, the son of the company's founder. After several problem-free test flights it was found that both aircraft lacked the predicted poor stall characteristics and the high speed aircraft, TG306, joined the formal research program on 23 August 1946. By the time De Havilland had safely taken it to 630 mph at altitude with no problems, it was decided he would take TG306 to break the world speed record. On a practice run over the Thames Estuary on 27 September 1946, the aircraft exceeded its structural limits at high speed and broke up, killing Geoffrey De Havilland, Jr, as the aircraft had no ejection seat. John Cunningham succeeded De Havilland as chief test pilot and took over flying the DH.108. To replace the lost aircraft, a third DH.108 was ordered and received the RAF serial VW120. It featured a more pointed nose, revised canopy and cockpit including a Martin-Baker ejection seat, and a higher thrust Goblin engine than what had powered the first two aircraft. Cunningham took VW120 up on its maiden flight  on 24 July 1947. With Cunningham and fellow test pilot John Derry flying VW120, a series of new speed records were set in 1948 and on 9 September of that year, Derry took VW120 past Mach 1 in a dive from 40,000 feet, making the DH.108 Swallow the first British aircraft to break the sound barrier- though it must be pointed out that Derry had for the most part lost control of VW120 during the supersonic portion of the flight but had safely recovered and landed. 

After flying demonstrations at the 1948 Farnborough SBAC air show, VW120 was handed over to the Royal Aircraft Establishment to join TG283 (the first Swallow) in the research program. On 15 February 1950 RAE test pilot Stuart Muller-Rowland was killed when VW120 broke up due to structural failure during a high speed test run. Three months later TG283 was lost and killed its test pilot, RAF Squadron Leader G.E. Genders, when it stalled at low speed and low altitude. 

Despite the loss of all three DH.108s with the loss of life, the data from the Swallow flight test program and the research program at the Royal Aircraft Establishment benefited not just the design of the DH.106 Comet jetliner, but also that of the DH.110 Sea Vixen naval fighter as well.

Source: Military Aircraft Monthly International, Volume 9, Issue 12. "A Deadly Swallow: The short sharp story of De Havilland's DH.108" by Nico Braas, p28-32.

The Dismal Career of the Chinese Mosquito

During the Second World War, a second De Havilland Mosquito production line was set up at the De Havilland Canada facility at Downsview Airport in Toronto. A total of 1,133 Mosquito aircraft were built at the Canadian production line but when the war ended in 1945, there were 100 aircraft completed at Downsview that had not yet been accepted by the Royal Canadian Air Force. These aircraft were put into flyable storage and joining them were another 110 surplus Mosquito bombers that were part of a larger group that were excess to the end of the war effort and were divided up amongst several storage sites across Canada. The Globe and Mail newspaper ran a story on 20 May 1947 about the stored aircraft at Downsview that were worth approximately $30 million and would be sold to the highest bidder or scrapped.

In the late summer of that year, a delegation arrived in Toronto wanting to purchase the Mosquito aircraft. They were the Chinese Nationalist,s dispatched by Generalissimo Chiang Kai-Shek, that were in the midst of a civil war against the Communists led by Mao Tse-Tung. Interestingly Chiang had sent a group to Downsview in 1944 to evaluate the Mosquito but no sale resulted. Now fighting a bitter conflict for control of China, the Mosquito bombers represented an irresistible deal that would give Chiang the most modern and still in those days, fast bombers available. Though the details of the transaction have been lost to history, the estimate is that for $5 million the Chinese Nationalists got approximately 300 aircraft, though most were to be obtained to act as spare parts for the flying aircraft. Four hundred spare Merlin engines were also included in the deal which included disassembly of the aircraft for transfer to China and then reassembly there for the Chiang's forces. De Havilland Canada would also provide training for the first cadre of pilots at Downsview. 

By October, an assembly bay at the plant was turned over to a "disassembly" line as the aircraft were taken apart and crated for transport to China. Given the political sensitivities of the time, the sale was noted by the Canadian government as a "commercial sale" and all publicity of the transfer was discouraged. The first group of fifteen Chinese pilots to be trained at Downsview started their conversion in February 1948 with former RCAF Mosquito pilots as instructors. Having previously flown B-25 Mitchells, the Mosquito was quite a handful for the Chinese pilots and in short order seven had to be written off. To avoid any publicity, the training program was quickly shifted to China and that first group of pilots ended up writing off another nine aircraft, resulting in the Mosquito being nicknamed "Lin Tai Yu" by the Chinese, after an empress who was beautiful but wicked. 

Chinese flight training began with the second group in April 1948 and very quickly another 13 accidents occurred, this time with fatalities. Despite the presence of numerous De Havilland Canada technical specialists and ex-RCAF pilots in China, the accident rate continued. A second training unit set up by Chiang's forces resulted in the write off of five aircraft in only five days. Many of the accidents were in ground handling, so De Havillland's technical staff built a taxi trainer that had struts on the rear fuselage to prevent ground looping. The Chinese even managed to wreck that trainer! The Mosquito force that Chiang Kai-Shek wanted spent more time in training than in actual combat missions. Some of this was the quality of his pilots, but a lot of it was that the Mosquito was simply too much airplane for what was a Communist guerrilla insurgency. With the Communists advancing and gaining control of more of China, the Canadians noted the deteriorating situation as the local currency was falling and non-Chinese citizens were leaving the country in droves. 

On 10 December 1948 the capital, Peking (now Beijing) fell to Mao's forces and the De Havilland team was ordered to depart immediately. Most of the team managed to escape via Hong Kong, but some of the lead engineers found themselves "retained" by the Nationalists to help keep their aircraft flying. De Havilland Canada's management arranged for a special DC-6 flight to get this last group out of China. Nationalist soldiers refused to allow the Canadians to depart, but gunfire on the airfield perimeter from advancing Communist forces provided a distraction for the Canadians who managed to successfully depart as the airfield came under attack. 

Needless to say, much like the less-than-salutory operational career of the Martin B-57 by the South Vietnamese Air Force in 1965, the career of the otherwise brilliant De Havilland Mosquito in China was very much a failure and an unusual footnote to the history of the Mosquito. 

Source: De Havilland in Canada by Fred W. Hotson. CANAV Books, 1999, p120-121.