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 , 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 and is designed to move the first engaging elements and/or the second engaging elements of the first and the second backrest holder 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 , 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 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 , and wherein the first and the second locking bolt 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 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 and is designed to move the first engaging elements and/or the second engaging elements of the first and the second backrest holder 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 , 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 is released, <EOS>