A method of low temperature start testing of turbofan engine was presented.And an experimental investigation was performed in a altitude test cell

focusing on studying the method of engine cold-soak process.The low-temperature starting characteristics of the turbofan engine were successfully obtained in the simulated altitude test cell using the low-temperature start testing method

confirming the feasibility of the method used in this testing.The test results give some helpful suggestions for future low-temperature start testing of aero-engines.The results show that:(1) Although the engine windmilling has some disadvantages on cold-soak process

it is still an economic and high-effective cold-soak method.(2) It is difficult to meet requirements of heat preservation time defined in GJB241 during real low-temperature start testing. Thus

it's recommended that the low-temperature test status should be judged using the temperature of lubricating oil. (3) The low-temperature environment has greater influence on the starter than on the turbofan engine.