Aerolite 4 Liferaft

The Aerolite 4 Liferaft (formerly known as Type 4U MK. 1) is a four person inflatable liferaft and is an item of primary survival equipment for occupants of an aircraft forced down at sea. lt has been approved to carry four persons with an overload of plus one third capacity.

The liferaft structure consists of a tubular buoyancy chamber and arch tube, a fabric floor and an automatically erected, single skin canopy for all-weather protection. The canopy incorporates a door which is used for entry and ventilation and is supported by the inflatable arch tube.

Until 1995, single-ply, neoprene-proofed nylon fabric was mainly used for the construction of the inflatable structure. Since 1995, a single ply, polyurethanecoated fabric has been used. The inflatable structure is coloured yellow.

Until 1995, single-ply rubber-proofed nylon has been used for the canopy. The colour was fluorescent flame orange. Since 1995, yellow polyurethane-coated nylon fabric has been used.

An operating/mooring line provides semi-automatic inflation on deployment.

The liferaft is inflated with carbon dioxide (CO2). The gas cylinder is stowed in a pocket or straps fitted beneath the liferaft floor. lt has a valve and an operating head.

The liferaft is furnished with lifelines, sea anchor drogue and other necessary items of equipment. Ancillary equipment is contained in an plastic bag stowed within the liferaft.

The complete liferaft assembly, deflated and folded, is packed as a selfcontained unit in a lightweight fabric valise designed to suit the internal stowage of the aircraft.

B. DETAIL

(1) Buoyancy Chamber and Arch Tube

The buoyancy chamber and arch tube are constructed as an integral uni inflated by a CO, cylinder. The chamber and arch tube are made from a number of fabric panels, joined together with a self-curing neoprene adhesive. Panel seams are covered with single-ply tape of similar materie for protection. The arch tube, which diametrically spans the buoyancy chamber, forms a support for the canopy when inflated.