Monday, 5 November 2012

De Havilland Aircraft Museum

Hidden down a single track lane and announced only by a softly spoken brown sign in the shadow of the M25 it is a treasure of aircraft design evolution. The de Havilland Heritage Centre is a fantastic collection of aircraft from a fast evolving period of aviation history. Having most of the collection come from the same company provides a consistency of approach that makes changes easier to identify between aircraft. It high-lights what drove design decisions, from payload capacity to engine integration.

The pride of the collection is a restored Mosquito Bomber, which sits in the main hanger along with a sibling under repair and collected parts of the original prototype. The Mosquito's success was its speed and simplicity of build. Seeing one up close, tapping the wooden hull and comparing it to the size of the two huge Merlin engines gives a small sense of how fast it was in flight.



Displayed around the hanger are detailed examples of its construction; cross sections of wing spars showing the build up of plywood and how clever use of the different directional properties of the wood were used for maximum strength. The similarity to carbon fibre design are compelling and obvious if you compare the wooden grain to the shimmering weave of composite.

The 1943 designed Vampire also contains many interesting design choices which can be seen up close. Its short fat shape is a result of the wide radial compressor found on early jet engines, unlike the more modern long and slender axial compressors. The body contains little more than the engine, a pilot and a pair of machine guns. The distinctive twin boom design was a result of the need to prevent power loss from the engine through long ducts; so the engine was allowed to exhaust directly into the air with no interference from an empennage structure.



This twin boom heritage lived on in the larger Venom and the twin engine Sea Vixen. This configuration was probably not necessary anymore, the original reason no longer being relevant, but all of de Havilland's existing design experience led to this configuration. 

The Heritage Centre has a very good collection which anyone with an interest in design can spend hours wandering through, seeing which ideas shaped the metal and wood in front of you. I suppose that is the most remarkable thing about humans: that we can create out of the world around us new shapes and designs to achieve something new. If often takes iteration, evolution and inspiration to do it, but that's what a collection of aircraft like this beautifully shows.