Flt Cracks Hot ((link)) -

Once a crack initiates, the "hot" environment changes the rules of failure. In a "cold" structure (like a wing spar), a crack grows primarily through mechanical fatigue—each flight adds a tiny amount to the crack length.

No discussion of “hot cracks” is complete without warnings: flt cracks hot

: Cracking happens between the liquidus and solidus temperatures when a thin film of liquid metal remains between solidifying grains. Once a crack initiates, the "hot" environment changes