Text in force at CS27-10: from CS27-0, effective 14 Nov 2003.
(a) For rotorcraft other than helicopters –
(1) The steady rate of climb, at VY must be determined:
(i) With maximum continuous power on each engine;
(ii) With the landing gear retracted; and
(iii) For the weights, altitudes, and temperatures for which certification is requested; and
(2) The climb gradient, at the rate of climb determined in accordance with sub-paragraph (a)(1), must be either:
(i) At least 1:10 if the horizontal distance required to take off and climb over a 15 m (50 ft) obstacle is determined for each weight, altitude, and temperature within the range for which certification is requested; or
(ii) At least 1:6 under standard sea-level conditions.
(b) Each helicopter must meet the following requirements:
(1) VY must be determined:
(i) For standard sea-level conditions;
(ii) At maximum weight; and
(iii) With maximum continuous power on each engine.
(2) The steady rate of climb must be determined:
(i) At the climb speed selected by the applicant at or below VNE;
(ii) Within the range from sea-level up to the maximum altitude for which certification is requested;
(iii) For the weights and temperatures that correspond to the altitude range set forth in sub-paragraph (b)(2)(ii) and for which certification is requested; and
(iv) With maximum continuous power on each engine.
ED Decision 2003/015/RM · Source