Throughout the years that rotorcraft have been on the British Register of Civil Aircraft, the single reciprocating engined, single main rotor helicopter has been the predominant representative of this particular family of aircraft. These helicopters were certificated to the British Civil Airworthiness Requirements (BCAR), Section G, “Rotorcraft,” issued in January 1954, which was written in terms of such helicopters.

During the past few years there have been significant changes in rotorcraft design—the turbine engine has been introduced and the multi-engined type has become a reality.

Basic changes in the design trends of any type of aircraft must inevitably involve a re-appraisal of the appropriate requirements by the responsible airworthiness authority. The BCAR are subjected to a constant process of refinement and revision and, as a result of the development of new types, the Air Registration Board has been considering the airworthiness implications and preparing amendments to most parts of Section G, but I wish to discuss only Flight Requirements which are in the main contained in one Sub-Section of Section G—Sub-Section G2. From the recent revisions I have extracted only the significant changes, although there are still problem areas I would like to put on record.