Air cylinders are made of aluminum, steel, or of a composite construction ( usually fiberglass-wrapped aluminum . ) Commonly an SCBA will be of the " positive pressure " type, which supplies a slight steady stream of air to stop toxic fumes or smoke from leaking into the mask.
42.
Directed to make copies of a new type of Luftwaffe life jacket, he made discoveries that were subsequently incorporated as standard in RAF " Mae Wests ", including the use of a compressed air cylinder for inflating the jacket and a pouch filled with a powerful fluorescent dye for spotting of a downed airman at sea.
43.
In a " soft-recoil system ", the spring ( or air cylinder ) that returns the barrel to the forward position starts out in a nearly fully compressed position, then the gun's barrel is released free to fly forward in the moment before firing; the charge is then ignited just as the barrel reaches the fully forward position.
