Passenger seat arrangement for installation in an aircraft, which comprises: - at least one seat unit with a backrest element and a seat element; and - a supporting frame, which carries the at least one seat unit and comprises at least one seat mounting, which has a first backrest holder, to which the backrest element can be fixed in a releasable and load-transferring manner in a first position on the seat mounting, and a second backrest holder, to which the backrest element can be fixed in a releasable and load-transferring manner in a second position on the seat mounting, wherein, in a state of the passenger seat arrangement in which it is installed in the aircraft, the backrest element is pivoted in relation to a longitudinal axis of the aircraft in a state in which it is fixed to the first backrest holder relative to a state in which it is fixed to the second backrest holder, wherein the backrest element comprises a plurality of first engaging elements, which are designed to engage releasably with one of a plurality of complementary second engaging elements respectively formed in the first and the second backrest holder (32, 34), in order to fix the backrest element in a load-transferring manner in the first or second position on the seat mounting, and wherein the passenger seat arrangement is characterized in that it also comprises: - a locking mechanism, which locks the backrest element to the first and the second backrest holder (32, 34) and is designed to move the first engaging elements and/or the second engaging elements of the first and the second backrest holder (32, 34) between a locking position, in which the first engaging elements are engaged with the second engaging elements of the first or the second backrest holder (32, 34), and a release position, in which a movement of the first engaging elements in relation to the second engaging elements of the first or the second backrest holder (32, 34) is released, wherein the first backrest holder comprises a first locking bolt and the second backrest holder comprises a second locking bolt, which form the locking mechanism, wherein the plurality of second engaging elements are arranged on a circumference of the first and the second locking bolt (48, 54), and wherein the first and the second locking bolt (48, 54) are respectively movable in a direction along their longitudinal direction, in order to move the second engaging element of the first or second backrest holder (32, 34) between its locking position and release position. - at least one seat unit with a backrest element and a seat element; and - a supporting frame, which carries the at least one seat unit and comprises at least one seat mounting, which has a first backrest holder, to which the backrest element can be fixed in a releasable and load-transferring manner in a first position on the seat mounting, and a second backrest holder, to which the backrest element can be fixed in a releasable and load-transferring manner in a second position on the seat mounting, wherein, in a state of the passenger seat arrangement in which it is installed in the aircraft, the backrest element is pivoted in relation to a longitudinal axis of the aircraft in a state in which it is fixed to the first backrest holder relative to a state in which it is fixed to the second backrest holder, - a locking mechanism, which locks the backrest element to the first and the second backrest holder (32, 34) and is designed to move the first engaging elements and/or the second engaging elements of the first and the second backrest holder (32, 34) between a locking position, in which the first engaging elements are engaged with the second engaging elements of the first or the second backrest holder (32, 34), and a release position, in which a movement of the first engaging elements in relation to the second engaging elements of the first or the second backrest holder (32, 34) is released,