PURPOSE: To speedily melt the snow heaped up on the wing of a plane free from danger by installing an injection device for jetting the combustion gas to an objective article on which snow is heaped up and controlling the injection quantity on the basis of the measured value of the surface temperature of the combustion gas injection objective article.

CONSTITUTION: In a jet engine 11, air is taken in from a front opened port part and compressed by a compression member, and the compressed air which is sent in is mixed with jet fuel and ignited and combusted in a combustion part, and the combustion gas (exhaust gas) is jetted from a rear opened port part by an infection part. The jet engine 11 is loaded on a base board 13 on a truck 18, and the height and direction are set arbitrarily so that the injection direction is directed to the heaped-up snow surface on the wing 12 of a plane. A radiation thermometer 16 is installed on the base board 13, and the temperature information supplied from the radiation thermometer 16 is sent into a temperature monitoring device, and a flow rate controller, i.e., the injection quantity of the combustion gas is controlled according to the temperature difference between the surface temperature information a standard temperature value.