Hot surface ignition of flammable liquids is a risk that must be mitigated for ground and air transportation vehicles. Hot surfaces are typically exposed to airflow, and leaking fuel or oil heated by these surfaces can vaporize and mix with the airflow. The past work for Minimum Hot Surface Ignition Temperature (MHSIT) is more than a decade old and is based on a complicated apparatus that led to some uncertainty in MHSIT measurements. Newer propulsion system designs lead to flow conditions beyond those available in the database. The FAA regulates flammable liquids used in the construction of aircraft. The design of engine features should minimize the probability of an internal fire that could result in hot surface ignition. The Gore Research Group, (GRG) has been investigating hot surface ignition of flammable aviation liquids under various flow conditions. The experimental apparatus shown above simulates jet- and spray-type liquid leaks that contact a uniformly heated cylinder and interact with crossflowing air over a range of velocities and temperatures.  This project is sponsored by Rolls-Royce.