Shutdown speed comes in two forms - steady speed, the speed at which the prop will be feathered, which typically comes with prevailing winds around the 65-75mph

Shutdown speed comes in two forms - steady speed, the speed at which the prop will be feathered, which typically comes with prevailing winds around the 65-75mph mark, and gust speed which is dealt with via brakes. Enough gusts will trigger a stop and feathering too. When the odd one catches fire, it's failed to feather or brake correctly.