Assume that a single plate of cockpit window glass had a width of 300 mm at 20 °C and that at that temperature there was a clearance all around the glass of 0.5 mm. The lowest temperature in which the airplane needed to be able to survive was –30 °C (very extreme winter conditions at JFK airport). The highest temperature was 153 °C (temperature at the absolute maximum speed of Concorde, Mach 2.2).

i. Find the maximum and minimum sizes of the glass–aluminum gap that would occur in use.
ii. Assume that the sealant was silicone rubber (thermal coefficient of Silicone Rubber = 250x10^-6/K) and that it was under zero stress at 20 °C. What would be the maximum tensile and compressive stresses experienced by the sealant in operation?