A rotor blade with an exterior shell extending in a span and chord wise direction and at least one control flap extending in essentially span wise direction to said exterior shell, particularly a rotor blade with an exterior shell extending in a span and chord wise direction and at least one control flap extending in essentially span wise direction to said exterior shell for a main rotor of a helicopter, said at least one control flap projecting in an essentially chord wise direction beyond said exterior shell, said rotor blade comprising: - at least one blade chamber inside said exterior shell and at least one passage from said at least one blade chamber to said at least one control flap, - load transmission means in said at least one blade chamber, said load transmission means comprising at least one piling type housing respectively with one actuator (8, 9), one flap drive (10, 11) and a longitudinal girder, said at least one piling type housing supporting centrally said one actuator (8, 9) distal to said longitudinal girder, said flap drive (10, 11) being oriented essentially in said chord direction and being in driving connection with said actuator (8, 9) and said at least one control flap, said longitudinal girder being fixed to said exterior shell and extending longitudinally in said essentially span wise direction, - at least one pivot bearing (35, 36) mounted to said longitudinal girder to support said at least one control flap, - at least one bearing (5, 6) at said at least one control flap for connection of said at least one control flap to said at least one flap drive (10, 11), and characterized in that it comprises - withholding means for each actuator (8, 9) with orientation essentially in said span wise direction, said withholding means being respectively fixed at one end to said exterior shell and at the other end to each actuator (8, 9), wherein said at least one piling type housing comprises at least one upper strap and at least one lower strap oriented essentially in said chord direction in between said longitudinal girder on the one side and the support for said at least one actuator (8, 9) on the other side, each of said upper and lower straps being aligned in chord direction relative to said at least one pivot bearing (35, 36) and said at least one actuator (8, 9), and said upper and lower straps being stiff in chord direction and flexible in span wise direction. - at least one blade chamber inside said exterior shell and at least one passage from said at least one blade chamber to said at least one control flap, - load transmission means in said at least one blade chamber, said load transmission means comprising at least one piling type housing respectively with one actuator (8, 9), one flap drive (10, 11) and a longitudinal girder, said at least one piling type housing supporting centrally said one actuator (8, 9) distal to said longitudinal girder, said flap drive (10, 11) being oriented essentially in said chord direction and being in driving connection with said actuator (8, 9) and said at least one control flap, said longitudinal girder being fixed to said exterior shell and extending longitudinally in said essentially span wise direction, - at least one pivot bearing (35, 36) mounted to said longitudinal girder to support said at least one control flap, - at least one bearing (5, 6) at said at least one control flap for connection of said at least one control flap to said at least one flap drive (10, 11), and characterized in that it comprises - withholding means for each actuator (8, 9) with orientation essentially in said span wise direction, said withholding means being respectively fixed at one end to said exterior shell and at the other end to each actuator (8, 9),