Text in force at CS27-10: from CS27-1, effective 30 Nov 2007.
(a) Climb. Static longitudinal stability must be shown in the climb condition at speeds fromVy - 19 km/h (10 knots) to Vy + 19 km/h (10 knots), with:
(1) Critical weight;
(2) Critical centre of gravity;
(3) Maximum continuous power;
(4) The landing gear retracted; and
(5) The rotorcraft trimmed at VY.
(b) Cruise. Static longitudinal stability must be shown in the cruise condition at speeds from 0.8 VNE - 19 km/h (10 knots) to 0.8 VNE + 19 km/h (10 knots) or, if VH is less than 0.8 VNE, from VH - 19 km/h (10 knots) to VH + 19 km/h (10 knots), with:
(1) Critical weight;
(2) Critical centre of gravity;
(3) Power for level flight at 0.8 VNE or VH, whichever is less;
(4) The landing gear retracted; and
(5) The rotorcraft trimmed at0.8 VNE or VH, whichever is less.
(c) VNE. Static longitudinal stability must be shown at speeds from VNE – 28 km/h (20 knots) to VNE with:
(1) Critical weight;
(2) Critical centre of gravity;
(3) Power required for level flight at VNE – 19 km/h (10 knots) or maximum continuous power, whichever is less;
(4) The landing gear retracted; and
(5) The rotorcraft trimmed at VNE – 19 km/h (10 knots).
(d) Autorotation. Static longitudinal stability must be shown in autorotation at:
(1) Airspeeds from the minimum rate of descent airspeed – 19 km/h (10 knots) to the minimum rate of descent airspeed + 19 km/h (10 knots), with:
(i) Critical weight;
(ii) Critical centre of gravity;
(iii) The landing gear extended; and
(iv) The rotorcraft trimmed at the minimum rate of descent airspeed.
(2) Airspeeds from the best angle-of-glide airspeed – 19 km/h (10 knots) to the best angle-of-glide airspeed + 19 km/h (10 knots), with:
(i) Critical weight;
(ii) Critical centre of gravity;
(iii) The landing gear retracted; and
(iv) The rotorcraft trimmed at the best angle-of-glide airspeed.
ED Decision 2007/013/R · Source