For the purpose of ratings on aircraft maintenance licences, aircraft shall be classified into the following groups:
66.A.5(1) Group 1 aircrafts
(1) Group 1: complex motor-powered aircraft, helicopters with multiple engines, aeroplanes with maximum certified operating altitude exceeding FL290, aircraft equipped with fly-by-wire systems, gas airships other than ELA2 and other aircraft requiring an aircraft type rating when defined as such by the Agency.
The Agency may decide to classify into Group 2, Group 3 or Group 4, as appropriate, an aircraft which meets the conditions set out in the first subparagraph, if it considers that the lower complexity of the particular aircraft justifies so.
66.A.5(2) Group 2 aircrafts
(2) Group 2: aircraft other than those in Group 1 belonging to the following subgroups:
(i) subgroup 2a:
— single turboprop engine aeroplanes,
— those turbojet and multiple-turboprop aeroplanes classified by the Agency in this subgroup because of their lower complexity.
(ii) subgroup 2b:
— single turbine engine helicopters,
— those multiple turbine engine helicopters classified by the Agency in this subgroup because of their lower complexity.
(iii) subgroup 2c:
— single piston engine helicopters,
— those multiple piston engine helicopters classified by the Agency in this subgroup because of their lower complexity.
66.A.5(3) Group 3 aeroplanes
(3) Group 3: piston engine aeroplanes other than those in Group 1.
66.A.5(4) Group 4 aircrafts
(4) Group 4: sailplanes, powered sailplanes, balloons and airships, other than those in Group 1.
GM 66.A.5 Aircraft groups
The following table summarises the applicability of categories/subcategories of Part-66 licences versus the groups/subgroups of aircraft: