Abstract: A rotor blade coupling device (9) comprising a torsionally rigid carrier (4) is disclosed, the carrier (4) being mounted in a manner which is free of centrifugal force between a thrust bearing (3) and a control bearing (5), resilient impact and pivoting movements of the rotor blade coupling device (9) being able to take place in a damped manner. The rotor blade coupling device (9) is clamped between a rotor head star (101) and a rotor head central piece (102) and held rotatably about the rotor axis A. The centrifugal forces which occur, are transmitted from a rotor blade holder (2) to the rotor head star (101) and thus kept away from the carrier (4).

Abstract: An observation port (4) in a primary structure (13) of a helicopter cabin (0) is disclosed, which is arranged between a pilot's seat (2) and a co-pilot's seat (3). The observation port (4) is delimited from the interior by an inner screen (15), and from the atmosphere by an outer screen (16), wherein the pilot can observe the space underneath the helicopter cabin (0) through the observation port (4). As a result of the configuration of the observation port (4) the pilot can assume an ergonomic and relaxed seating position at any time, even when he is executing flights with suspended loads. By means of the observation port (4) and the windows (15, 16), which extend laterally between the two pilots' seats (2, 3), a novel unrestricted vertical visual frame of reference onto the suspended load is achieved, wherein the length of the load cable has practically no influence.