INTRODUCTION

The requirements of Clauses 2.21 to 2.25 apply to all aeroplanes, and are intended to ensure that satisfactory flying and handling qualities are obtained in flight and on the ground, regardless of the type of design or flight control system.

The requirements of this Clause 2.1 and Clause 2.23 and Part 1 Section 4, Clause 4.9 apply to all aeroplanes. Clauses 2.21 and 2.22 apply to conventional aeroplanes and to VSTOL aeroplanes in conventional flight. Clause 2.24 applies to VSTOL aeroplanes at speeds below Vcon, and also states the additional requirements for thrust vectoring in forward flight (VIFF) at all speeds permitted for this manoeuvre. The speed Vcon shall be chosen by the contractor so that there is no gap between the requirements of Clause 2.24 and those of Clauses 2.21 and 2.22. At Vcon, and in any overlap inapplicability, the most stringent requirements of all relevant sections of Clauses 2.1, 2.21, 2.22, 2.23, 2.24 and Part 1, Section 4, Clause 4.9 shall be met.

It is desirable that the specified flying qualities should be achieved by good aerodynamic and mechanical design. However automatic devices may be used where an overall benefit accrues provided that the system as a whole meets the requirements of Leaflet 55.

The Contractor shall advise the Project Team Leader of any special penalties of cost, performance or maintenance which may result from meeting a particular requirement of this Clause.