Patent ID: 8485473

Claim:
A method of detecting frost and/or frosty conditions on an aircraft in flight, on which at least one free external surface, exposed to an aerodynamic flow around the aircraft, on a skin of one of the aircraft a probe projecting from the aircraft into the aerodynamic flow, is reserved as a detection-sensitive surface, on which a build-up of frost or ice is likely to be formed in flight in frosty conditions, the method including at least one cycle with at least the following steps, comprising: monitoring variations of a thermal flux between said sensitive surface and the aerodynamic flow, which are caused by variations of a forced convection thermal exchange coefficient between said sensitive surface and the aerodynamic flow according to a build-up of frost or ice, considering that the aerodynamic flow has caused a film of frost or ice formed on said sensitive surface to tear off if, after a time interval during which a slow or substantially zero reduction of said thermal flux is observed, an abrupt increase is detected in said thermal flux at a temperature close to the melting point of the frost or ice, and following a detection of a tearing-off of frost or ice, delivering a signal indicating the presence of frost or frosty conditions.