2.1 D-value means the largest dimension of the helicopter used for
assessment of the helideck when its rotors are turning. It establishes the required area of
foam application.
2.2 Deck integrated foam nozzles are foam nozzles recessed into or edge
mounted on the helideck.
2.3 Foam-making branch pipes are air-aspirating nozzles in tube shape
for producing and discharging foam, usually in straight stream only.
2.4 Helicopter landing area is as defined in SOLAS regulation II-2/3.57.
2.5 Helideck is as defined in SOLAS II-2/3.26.
2.6 Hose reel foam station is a hose reel fitted with a foam-making
branch pipe and non-collapsible hose, together with fixed foam proportioner and fixed foam
concentrate tank, mounted on a common frame.
2.7 Monitor foam station is a foam monitor, either self-inducing or
together with separate fixed foam proportioner, and fixed foam concentrate tank, mounted on
a common frame.
2.8 Obstacle free sector is the take-off and approach sector which
totally encompasses the safe landing area and extends over a sector of at least 210º,
within which only specified obstacles are permitted.
2.9 Limited obstacle sector is a 150º sector outside the take-off and
approach sector that extends outward from a helideck where objects of limited height are
permitted.