Razor-sharp operation

Engineers at BAE Systems have hailed the design and production of a key component for the Joint Strike Fighter (JSF) programme as one the most complex feats of machining ever undertaken.

The titanium heatshield — which is located near the exhaust of a power pack on the plane’s aft fuselage — is to be fitted to the F-35, the first JSF to roll off the production line.

Titanium has been used because the heat-resistant properties required could not be achieved using carbon fibre, from which the outer surface of the aircraft is predominantly made.

Titanium is one example of a heatresistant, high-strength material used in aircraft to counter the effects of the heat barrier — the high temperatures caused by friction of air against the outer surfaces of the aircraft. The heatshield is designed to protect the carbon-fibre panels from temperatures up to 260º.

What started life as a 1.8m x 1.2m rectangular metal bar, 14cm thick and weighing over a tonne, now resembles a giant razor blade. It has been designed and machined to measure around 1.2m x 0.9m but narrowing to a tiny fraction of a centimetre at its edges, a stipulation to ensure it did not affect the special characteristics of the JSF.