What component is installed on the training guided missile (TGM)-65 in place of the rocket motor and hydraulic actuation system?

• A. Film recorder or ballast
• B. Guidance unit
• C. Digital computer system assembly
• D. Adapter group computer test set

Answer: (A)

For training missiles, you replace the propulsion and actuation hardware with something that lets you study the guidance system without firing. In the TGM-65, the substitute device is a film recorder or ballast. The film recorder logs telemetry and sensor data on film, giving a permanent record of how the guidance logic and control signals would behave in flight. Ballast, on the other hand, can be used to match the missile’s inertial characteristics (mass distribution and weight) so the actuators and control surfaces respond as they would in a real flight, without needing a rocket motor or hydraulic system to operate.

This approach is about safe, data-rich testing of the guidance and control system rather than executing a propulsion event. The other options would either be parts of the guidance system itself or ground-test equipment, not substitutes for the rocket motor and hydraulic actuation system installed on the training missile.