A store suspension and release unit, comprising a suspension hook, a primary latch mechanism (114, 116, 118, 120, 122, 124) which can be actuated to release the suspension hook for movement, thereby to release a store, the store suspension and release unit further comprising a safety latch mechanism (128, 130, 132, 136) movable from a locked position in which it blocks movement of the suspension hook, to an unlocked position in which the suspension hook is free to move and release the store; characterised in that the suspension hook is mounted for rotation on a pivot shaft which also carries a nib fixed for rotation with the suspension hook, the primary latch mechanism comprises a first rotary arm and the safety latch mechanism comprises: a second rotary arm drivingly attached to a rotary actuator, and a safety latch mounted for rotation on a shaft and connected to the second rotary arm by a locking pin received in a drive slot; the first rotary arm being positionable in a horizontal rest position in which the second rotary arm is resiliently biased to a generally vertical rest position and a detent projection on the first rotary arm is held in a notch in the second rotary arm, preventing the first rotary arm from rotating; whereby energising the rotary actuator rotates the attached second rotary arm away from its rest position thereby disengaging the detent projection from the notch whereby the first rotary arm is free to rotate; such rotation of the second rotary arm also rotating the safety latch in the opposite direction about the shaft, via the locking pin and drive slot connection (136, 138), whereby the locking pin is moved out of the path of rotation of the nib, so that the hook is free to rotate to its disengaged position; and de-energising the rotary actuator moves the locking pin back in front of the nib if the hook has jammed whereby then if the nib presses against the locking pin attempting to further rotate it about the shaft the second rotary arm is biased via the pin and slot connection (136, 138) towards its rest position whereby the second rotary arm is prevented from rotating by engagement of the detent projection and the notch. a second rotary arm drivingly attached to a rotary actuator, and a safety latch mounted for rotation on a shaft and connected to the second rotary arm by a locking pin received in a drive slot; the first rotary arm being positionable in a horizontal rest position in which the second rotary arm is resiliently biased to a generally vertical rest position and a detent projection on the first rotary arm is held in a notch in the second rotary arm, preventing the first rotary arm from rotating; whereby energising the rotary actuator rotates the attached second rotary arm away from its rest position thereby disengaging the detent projection from the notch whereby the first rotary arm is free to rotate; such rotation of the second rotary arm also rotating the safety latch in the opposite direction about the shaft, via the locking pin and drive slot connection (136, 138), whereby the locking pin is moved out of the path of rotation of the nib, so that the hook is free to rotate to its disengaged position; and de-energising the rotary actuator moves the locking pin back in front of the nib if the hook has jammed whereby then if the nib presses against the locking pin attempting to further rotate it about the shaft the second rotary arm is biased via the pin and slot connection (136, 138) towards its rest position whereby the second rotary arm is prevented from rotating by engagement of the detent projection and the notch.