Flight test methods and results

The differences in the pitch rate generated during the two tests will lead to differences in the amount of aft stick required. The main reason for the difference is the greater pitch damping moment (Mq) generated in the turn requires more aft cyclic to compensate. Since there will usually be a linear relationship between longitudinal cyclic stick position and cyclic pitch (Bl) these equations can be used to explain the difference in test results assuming all other factors are equal, see Fig. 5.7.

Подпись: Fig. 5.7 Manoeuvre stability test data.

The figure shows that as far as the pilot is concerned the helicopter will appear more manoeuvre stable in a descending turn than during a pull-up. Note, however, that since MBl appears in both equations the actual amount of manoeuvre stability (size of Mw) cannot be quantified since the size of the control deflection is dependent on the control power.

Leave a reply
