Skycraft.
Skycraft Services Limited was founded in 1987 to represent Hoffmann Propeller in the United Kingdom.
With a significant local population of light aircraft the Hoffmann fixed pitch and constant speed propellers supplied by Skycraft became established as a popular choice. The initial sales success expanded to include the entire range of Hoffmann products and in order to provide local engineering support, investment in a propeller workshop was made thereby establishing the UK Hoffmann Service Station.
To consolidate the Hoffmann market product developments were undertaken to address the demands for specialist propellers. To assist the British Gliding Association implement its noise abatement policy for glider tugs, new 4-blade propellers were developed by Hoffmann and tested & certified by Skycraft for use at gliding sites. With growing activity in restoration of former military historic aircraft, such as the iconic Spitfire, new blades for these large Rotol Airscrews were developed in co-operation with Dowty Rotol Limited. Attention was also given to establishing and supporting propellers on the RAF Vigilant, Firefly and Tutor fleet training aircraft.
Today Skycraft provides high quality propeller engineering solutions across all sectors of the UK market fully utilising Hoffmann products. It also has a worldwide customer base for its historic military propellers which has recently been extended to Russian and German types.
The enormous interest in the iconic British Supermarine Spitfire aircraft is not limited to the UK and is characterised by frequent movement of these aircraft across the globe between avid collectors. Skycraft is privileged to be a contractor supporting this activity working closely with operators especially in North America, Europe, Australia and New Zealand. Skycraft works closely with The RAF Battle of Britain Memorial Flight in support of the Rotol Airscrews of their Spitfires & Hurricanes and their major air display programmes during the summer months attract worldwide attention and is seen as a national treasure.
WHAT WE HAVE ACHIEVED
Skycraft has a well-established specialist propeller capability based on precision engineering and ‘attention to detail’ .
Unique working relationships with private historic aircraft operators around the world.
Completion of over 10,000 propeller overhauls for propellers operating across 50 – 2500 hp engines.
Specialist capability in training & support of propellers in use on hovercraft and wind tunnel testing.
Statutory EASA, CAA, MAA compliance including maintenance, design and manufacturing approvals.
The UK Sales & Service Centre for Hoffmann Propeller working together on new products and market development.
An unenviable reputation for our propeller engineering in the historic aircraft market sectors with over 50,000 flying hours amassed on Hoffmann replica blades.
Support of predominately military fleet operators who have flown over 1,000,000 flying hours with Hoffmann propellers.
THE BASICS
Propeller blade production involves a combination of wood composite construction, CNC machining and skilled hand working. Seasoned dried timber is given preference to other materials as it is light, strong, notch insensitive and durable.
For the manufacture of variable pitch propeller blades, hardwood is widely used at the blade root, it is spliced to a special densified wood laminate. Timber of approximately 24 mm thickness is cut in 60 mm wide strips in a grain selection process. These strips are glued in a hydraulic press with a temperature and humidity controlled environment. The glued strips have special grain alignment to improve the quality and warping distortion compared to plain timber. These layers are spliced together and then glued into rectangular blocks.
Hoffmann HO21-198B 140LK propeller
The blocks are CNC machined to create the basic shape of the propeller blade. The contour of the aerofoil is progressively refined by hand to a fine tolerance with precise templates at the blade reference stations. During the finishing phase the complete blade is sheathed with synthetic fibre and a metal or polymer guard is installed along the leading edge to provide erosion protection. Finally the propeller is painted in a modern environmentally friendly resin.
Our mission
Our mission is to make an active contribution by participating in, and supporting the development of, the propulsion system markets in land, sea and air.
Skycraft is involved in the complete spectrum of a product cycle; starting with market analysis, working on product development with Hoffmann, undertaking field trials, participating in certification and providing support for our products.
Junkers VS-II propeller
Innovation as well as technical development are shared strategic objectives and today’s aviation legislation demands that new ideas are safe, economic and environmentally friendly. Hoffmann who has experience spanning 60 years’ of continuous development has designed new aerofoil sections which provide high efficiency low-noise characteristics. Aerodynamics, stress calculations, and flight simulation are accomplished by means of CAD/CAM combined with rigorous prototype testing.
BRITISH HISTORY
De Havilland and Supermarine are two British aircraft manufacturers established in the 1920’s who had a profound effect on aircraft development.
Fortunately many of these aircraft are flying worldwide in immaculate condition and are a tribute the design teams, especially the aeronautical engineers Geoffrey de Havilland and Reginald Mitchell. It is not surprising that these historic aircraft whose popularity continues to grow are a significant part of the Skycraft business.
De Havilland Moth series of aircraft proved to be just what the 1930’s flying world was waiting for. The Tiger Moth, quickly became a commercial success especially as a trainer and was produced in large numbers. An estimated 8000 Tiger Moths were operated by the Royal Air Force and other Allied Air Forces. When decommissioned they were sold for as little as £ 5 to civilian flying schools and today many continue in widespread use maintained and operated by dedicated private owners.
Rotol R12/4F5/4 propeller
Supermarine initially focused on seaplanes & flying boats, and one of their first land-planes was the Spitfire. Fortunately 300 Spitfire’s have survived the ravages of time and are exhibits in aircraft museums around the world. With the extraordinary level of interest in the Spitfire today as the instantly recognisable iconic fighter of the WWII, restoration to airworthy condition is a realistic proposition given a substantial investment which has been made in restoration. Specialist aircraft organisations have developed capabilities to repair and restore the aircraft to immaculate flying condition and an ever increasing number are flying today.
“Man must rise above the Earth -to the top of the atmosphere and beyond -for only thus will he fully understand the world in which he lives.”