Abstract: A helicopter landing pad and hangar structure attachable particularly to the deck of a ship in a manner requiring a minimum of space on the deck during both helicopter landing and storage, and also requiring no penetration of the deck or other substantial modification of the ship structure, comprises an enclosure including a framework, side walls, and a plurality of panels supported at the top of the side walls and slidable horizontally to an inner retracted position closing the enclosure or to an outer extended position opening the enclosure and extending laterally past the side walls. A lifting platform is movable vertically to a lower position within the enclosure or to an upper position horizontally aligned with the plane of the panels.