(3) Constant Pressure Refueling System (Type III).
(a) The Type I hydrant system can refuel aircraft at rates between 1200 to 6000 GPM using a
hydrant hose truck rather than a hose cart.
(b) The constant pressure is maintained by a series of continuously running pressure pumps.
(c) The system detects a drop in pressure when a hydrant hose truck connects to a hydrant and
brings the pressure up until the rated flow is reached.
(4) Hot Refueling System (Type IV).
(a) This system is used specifically for refueling aircraft with engines running or in a shelter.
(b) The system is similar in all respects to the Type I system except that it uses a pantograph to
connect to the aircraft rather than a hydrant hose truck.
c. Fuel-Servicing Equipment.
(1) R-9 tank truck.
(a) The R-9 is a 5,000-gallon fuel-servicing vehicle used for refueling and defueling aircraft.
(b) The vehicle has two hose reds, two 300-GPM meters and a 600-GPM filter/separator.
(c) The hose reels are both 60 feet long. One hose reel has a 3-inch hose with a single point
refueling nozzle attached. The other hose reel has a 2-inch hose with an overwing nozzle attached.
(d) The centrifugal pump is rated at 600 GPM and is powered by the R-9's engine through the
use of a PTO. The R-9 can refuel from both nozzles simultaneously at 300 GPM or through the 3-inch hose and
both meters at 600-GPM. The R-9 can defuel an aircraft at a rate of 200 GPM.
(e) The R-9 can be bottom loaded to fill the tank. The tank is a single piece of aluminum sheet
with 15 baffles.
(f) The R-9 control panel has three gages to monitor pressures: a pressure differential gage to
monitor the filter/separator; a nozzle pressure gage; and a pump discharge pressure gage.
(2) R-11 tank truck.