MOC VTOL.2220 Ground and water load conditions

1.      General

(a)      Loads and equilibrium. For limit ground loads –

(1)     The limit ground loads obtained in this MOC should be considered to be external loads applied to the aircraft structure as if it were acting as a rigid body; and

(2)     If significant, the structural dynamic response of the airframe should be taken into account considering all critical mass distributions; and

(3)     In each specified landing condition, the external loads should be placed in equilibrium with linear and angular inertia loads in a rational or conservative manner.

(b)     Critical centres of gravity. The critical centres of gravity within the range for which certification is requested should be selected.

2.      Ground load conditions and assumptions

(a)      For specified landing conditions, all weights should be considered up to the maximum weight. Total lift may be assumed to act through the centre of gravity throughout the landing impact. This lift may not exceed two-thirds of the design maximum weight.

(b)     Unless otherwise prescribed, for each specified landing condition, the aircraft should be designed for a limit load factor of not less than the limit inertia load factor substantiated under MOC VTOL.2235 “Limit drop test”.

3.      Tyres and shock absorbers

CS 27.475 Amdt. 6 is accepted as a means of compliance.

4.      Landing conditions

(a)      The following landing conditions apply depending on the configuration of the VTOL

(1)     The following landing conditions apply to landing gear with two wheels aft, and one or more wheels forward, of the centre of gravity:

(i)      The level landing conditions in CS 27.479 Amdt. 6 are accepted as means of compliance.

(ii)     The tail-down landing conditions in CS 27.481 Amdt. 6 are accepted as means of compliance.

(iii)     The one-wheel landing conditions in CS 27.483 Amdt. 6 are accepted as means of compliance.

(iv)     The lateral drift landing conditions in CS 27.485 Amdt. 6 are accepted as means of compliance.

(v)     The braked roll conditions in CS 27.493 Amdt. 6 are accepted as means of compliance.

(2)     The ground loading conditions for landing gear with tail wheels in subparagraphs (a) to (h) of CS 27.497 Amdt. 6 are accepted as means of compliance.

(3)     The ground loading conditions for landing gear with skids in CS 27.501 Amdt. 6 are accepted as means of compliance.

(b)     CTOL aircraft should be designed for the additional loading conditions specified in this paragraph. In showing compliance with this paragraph, the following apply:

(1)     The level landing conditions in CS 23.479(a) and (b) Amdt. 4 are accepted as a means of compliance.

(2)     The tail down landing conditions in CS 23.481 Amdt. 4 are accepted as a means of compliance.

(3)     The one-wheel landing conditions in CS 23.483 Amdt. 4 are accepted as a means of compliance.

(4)     The sideload conditions in CS 23.485 Amdt. 4 are accepted as a means of compliance.

(5)     The braked roll conditions in CS 23.493 Amdt. 4 are accepted as a means of compliance.

(6)     The supplementary conditions for tail wheels in CS 23.497 Amdt. 4 are accepted as a means of compliance.

(7)     The supplementary conditions for nose wheels in CS 23.499 Amdt. 4 are accepted as a means of compliance.

(8)     The supplementary conditions for ski-planes in CS 23.505 Amdt. 4 are accepted as a means of compliance.

(c)      The ski landing conditions in CS 27.505 Amdt.6 are accepted as a means of compliance.

5.      Taxiing Condition

(a)      CS 27.235 Amdt. 6 is accepted as a means of compliance.

(b)     In addition, for aircraft with conventional take-off and landing (CTOL) capability the aircraft should be designed to withstand the loads that would occur when take-offs and landings are performed on unpaved runways having the roughest surface that may be expected in normal operation.