Ron’s Rambles

The deHavilland Museum, London Colney My friend and I visited this small museum a couple of months ago. It is situated in the grounds of Salsbury House (the place where the team that designed the Mosquito were hidden away in the early part of the second world war) and is accessed down a narrow lane. Small it may be but to our surprise it proved to be one of the most interesting and we finished up spending far more time there than we had expected. Geoffery deHavilland was a pioneer aviator starting off in the early days of the twentieth century by building and flying his own aeroplane. He went on to work as a designer of aeroplanes that were used in the first world war, all his designs had the prefix DH in front of their names. After that war he established his own company which went on to play a major role in the development of aviation in the UK, always pushing ahead and often leading the world. In 1934 they produced the famous little Comet twin engine racer that won the London to Sydney race. In the second world war they produced the Mosquito a very fast and very versatile aircraft that played a major role in winning that war. They were pioneers in the jet age, producing the first jet fighter to go into service and the first jet airliner, where they used the famous name of Comet again. The museum was started by a group of enthusiasts who wished to preserve what it could of the Mosquito story, including, of course, a complete Mosquito and was known as the Mosquito museum. Since then it has grown slowly, it has just completed a new additional hanger and has spread itself to include all things deHavilland. They have managed, with a limited number of exhibits, to convey much of the deHavilland story. It is said that, back in the 1930s, Geoffery was dissatisfied with the aero-engines that were available and decided to build his own, this led to the famous ‘Gipsy’ range of piston engines. It was deHavilland’s Gipsy engines that were used in the Comet racer. This work led eventually to the establishment of a separate company, the deHavilland Engine Co. The Engine Co was in at the very start of the jet age, producing the Ghost and Goblin engines. It was Ghost engines that powered the Comet, the first Jet liner. The museum contained examples of almost every engine type that the company produced and that was pleasing for me as I had had some association with a number of them. The Mosquito, as most people are aware, was made largely of wood, partly due to the demand for aluminium by other aircraft types which reduced the availability of this metal. Whilst people may know that it was made of wood, how it was made may not be well understood. At the museum there are examples of the way in which the structure was constructed which we found particularly interesting. Using relatively thin ply wood they created light structures of considerable strength, the bomber variant could carry a 4000lb bomb load, the heavy Rolls Royce Merlin engines were mounted in wooden structures and the undercarriage transmitted the loads on landing into a wooden structure. There is no doubt that it was a remarkable achievement, sometimes called the wooden wonder. Wooden it may have been but in appearance and in operation it looked and was one of the most advanced aeroplanes in its time and was the fastest fighter in the world for a while, German fighters could not catch it. The downside of wood has been that there are few examples left to see and none, I think, that are airworthy. I have been told that an American has had one built which is able to fly. There are other Mosquito exhibits in museums in this country but It does seem a shame that it took a group of enthusiasts to keep the story alive rather than a national effort. The Horsa troop carrying gliders were made by Airspeed, a subsidiary of the deHavolland company, using similar construction methods with wood. They have exhibits related to many other deHavilland success stories, including the Trident, and the DH 146. The latter went on for many years as the BAe 146, it was, and probably still s, part of the Queen’s flight. The Vampire, the first jet fighter to go into service in WW2 is well represented. Many variants of the Vampire were sold all over the world. Most of these exhibits are parts of aeroplanes but sufficient to understand what was achieved. deHavilland was a famous name, they employed many thousands and went on to be a significant component of British Aerospace. The propeller company became an advanced technological company that became BAe Systems, producing missile systems of all kinds and advanced space technology. The engine company was absorbed into Rolls Royce. The name did become tarnished as a result of two major disastrous failures, the disintegration in the air of Comet 1s and the disintegration of the DH 110 at Farnborough. They were the result of trying to push the boundaries, the Comet1 was a particular tragedy for the passengers and for the company. They knew about metal fatigue, they knew about stress in structures, what they didn’t know was the way in which the stress in the skin of the aircraft resulting from a pressurised interior would become so concentrated in the corners of the square windows, and in those days there was no way that they could have measured it. The Comet 4 went on to be a sound aeroplane, as was the Trident, I had the pleasure of flying in both types on more than one occasion.