CSP–520N–1
MD 520N (500N) ROTORCRAFT FLIGHT MANUAL
R
Revision 2
7–13
FAA Approved
7–8. FUEL SYSTEM – SERVICING
Refueling vehicle should be parked a minimum of 20 feet from helicopter dur(
ing fueling operation.
Before starting fueling operation, always ground fueling nozzle or fuel truck to
GROUND HERE receptacle (Ref. Figure 7−4) or to another bare metal location.
Comply with the following precautions when servicing the fuel system.
Turn off electrical switches and disconnect any external power from
helicopter. Electrically ground helicopter prior to refueling or
defueling. Static discharge spark in presence of fuel vapors can
cause fire or an explosion.
Cold weather fuels:
Grade JP−4 (MIL−DTL−5624), grade JP−5, and grade JP−8 (MIL−
DTL−83133) type fuels contain anti−ice additive which conforms to
MIL−1−27686
(or later). These fuels do not require additional anti−ice addi(
tive.
Cold weather fuel mixtures
To assure consistent starts at temperatures at or below 4
°
C (40
°
F), a
mixture of AVGAS and jet fuels (other than JP−4 or Jet B) may be used.
The alternate avgas−jet fuel mixture is not recommended for warm
weather operation.
Refer to Allison Operation and Maintenance Manual for additional cold
weather fuel mix and blending instructions.
Filling:
The fuel system has two fuel cells that are interconnected for simultaneous
flow and venting.
Refuel the helicopter with the proper fuel as soon after landing as possible
to prevent moisture condensation.
Keep fuel nozzle free of all foreign matter.
Fuel tank servicing is through the cell filler neck on the right side of the
fuselage. The right side fuel cell contains the gravity filler port and cap.
Check filler cap for security after refueling.
WARNING
