Oil-out conditions, or conditions in which an aircraft is operating without any oil in its gearbox or transmission, are devastating for an aircraft's hardware. Even the sturdiest gears usually can't last 30 minutes under such conditions before they catastrophically fail, and the whole system usually follows shortly after. That doesn't leave pilots with a whole lot of time to find a suitable location to land in the case of an oil-out emergency.

This work establishes a baseline for aerospace spur gear behavior under oil-off conditions. The collected test results document a different oil-off time, dictated by material used.