Test apparatus for measuring jet engine thrust

Apparatus for simultaneously measuring variables to calculate total thrust generated from a turbofan jet engine having a lengthwise axis and which is characterized by (1) a section for generating drive gases, (2) a fan section which rotates about the lengthwise axis in response to the drive gases and which includes (i) exterior blades which rotate with the fan section for generating a propelling force, and (ii) an outer cowling, and (3) an outlet section for exhausting the drive gases to the atmosphere to provide a further propelling force, the apparatus comprising:

• a. a cradle for supporting the engine;
• b. means for suspending the cradle from a support structure so as to permit movement of the cradle in the lengthwise direction;
• c. means for measuring a forward force generated by the drive gases which are exhausted to the atmosphere for calculating the nozzle gas thrust, said measuring means including load cell means which are connected between said support structure and said cradle;
• d. dynamometer means including a rotatable portion, for measuring a torque generated by the engine fan section for calculating the thrust output of the fan section;
• and
• e. drive gear means for connecting said dynamometer means to the engine fan section, said drive gear means including belt means which are removably connected to the fan section and to the rotatable portion of said dynamometer means so as to transmit a rotational force between said fan section and said dynamometer means.