Temperature Effects on Aircraft Structures.
Technology has advanced us to the stage where we now have an upper and lower temperature limiting envelope.
The upper limit for titanium currently limits Mach nos to a bit over 3.0. Tiles on the space shuttle get us to my guess of about Mach 10.0+ for a short period.
At the low temp end we have to contend with the two known coldest areas in our planet's atmosphere where temps get as low as -95 C. One of these areas is NE of Darwin, Australia. The other is off the West coast of South America. Oddly upper air tempertures are coldest over the tropics and warmest over the poles.
Most metals become more brittle as their temperature lowers resulting in a lowering of their tensile strengths. This is particularly relevant if there happens to be a crack or an anomoly in the material. Recognition of this for the steel structure of the F-111 contributed to the development of the the "Cold Proof Test" which subjected every aircraft to repetetive full equivalent flight load testing (+7.3 to -3.5 g) at a temperature of -40 C. A successful test gave/gives confidence for 5,000 hours of normal flying to a Mil 8866 g exceedence spectrum. The 5,000 hours was given a 50% safety factor and became 2,500 hours.
Don't yet know how composites behave approaching their temperature limits. Can anyone comment?