Adverse yaw/proverse yaw/heading delay
Cyclic-only turns are also conducted to determine the adverse yaw or proverse yaw characteristics, whether any heading delay is apparent and whether the aircraft possesses the capability to perform co-ordinated turns with no pilot input on the pedals. The technique consists of TO1C-C initiated from a ball-centred or zero-sideslip wings-level attitude accomplished with lateral cyclic displacements of various rates consistent with the role of the aircraft. Collective remains fixed and airspeed is maintained with longitudinal cyclic. The heading, the sideslip and the yaw rate response to the control input are noted. A roll out of the turn onto a predefined heading at role-relatable roll rates is often attempted to qualitatively evaluate the ability of the pilot to select a desired heading within narrow tolerances.
5.5 TIME DOMAIN METHODS FOR CONTROL RESPONSE TESTING
The purpose of control testing in the time domain is to evaluate the dynamic modes of the aircraft using inputs that although generated in a very stylized manner represent in some way the control strategies commonly used by pilots. Typical inputs include steps and pulses. Since these inputs have been used for many years as means to determine the control response characteristics of rotorcraft, specific handling quality specification requirements exist which are based on these test methods. More recently as a result of the handling qualities research conducted during the LHX programme (the forerunner of the RAH-66 Comanche) the concept of manoeuvre quickness has been introduced [5.3]. Since testing to gather quickness data is an extension of the pulse input technique [5.4], it is discussed below.