Ground test tool adapter plate

A ground test tool (GTT) adapter plate and speed sensor assembly, comprising:

• an adapter housing;
• mounting features disposed in the adapter housing to secure the adapter housing between a RAT system component and the GTT;
• a shaft comprising first and second splines to register with complementary splines of the RAT system component and the GTT such that rotational energy input from the GTT is transmittable to the RAT system component along the shaft;
• bearings disposed to rotatably support the shaft within the adapter housing;
• and
• a speed sensor coupled to the adapter housing and configured to measure a rotational speed of the shaft from rotational energy driven rotations thereof.

A method of conducting a ground test of a RAT system, the method comprising:

• securing an adapter plate between a ground test tool (GTT) and a RAT system component,
• wherein the securing comprises inserting an adapter plate output spline into the RAT system component, receiving an output spline of the GTT in an adapter plate input spline and affixing opposite sides of the adapter plate to the GTT and the RAT system component, respectively;
• the method further comprising:
• running the GTT to drive rotations of the RAT system component;
• and
• sensing a rotational speed of a shaft flange axially interposed between the adapter plate output and input splines.