Van's Aircraft RV 12iS, Дополнение к руководству по летной подготовке

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Revision: 4 Date:
09/08/20
RV-12iS Flight Training Supplement 3-2
Water remaining in the system in cold conditions may freeze in the fuel system lines and cause a blockage. A partially
blocked fuel line should be noted by a corresponding drop in the fuel flow rate (fuel flow rate only available on Rotax 912
iS engines).
HOT WEATHER OPERATION
Satisfactory engine cooling and cooling of critical electrical components such as the 912ULS voltage regulator has been
demonstrated for this aircraft at an outside air temperature of 100
O
F (38
O
F). This is not to be considered an operating
limitation. Extra caution should be used when operating near or above this demonstrated temperature. Beyond the
normal reductions in aircraft performance there are three main areas of focus when operating at elevated temperatures,
coolant temperature while operating at low rpm on the ground, oil temperature during climb and elevated temperatures
in the engine compartment beneath the cowling after shutdown.
Operating on the ground at idle rpm, little air is passed through the radiator and oil cooler. When temperatures are
elevated a minimum 2000 rpm should be used instead of idle (which on the Rotax 912 iS may be as low as 1440 rpm).
If the coolant temperature begins to rise engine rpm should be increased to 3500 rpm and above. This will push air from
the propeller through the radiator and return the coolant temperature to a stable value within the operating limitations of
the engine. Coolant temperature will rise more quickly with the wind coming from behind the aircraft or directly from the
right side.
During climb oil temperature will begin to rise. The oil cooler has been designed for optimal flow and heat dissipation for
the aircraft in a V
Y
climb. When climbing at airspeeds below V
Y
oil temps may reach elevated levels. If this happens
lower the nose and choose a higher climb airspeed that will stabilize the oil temperature within operational limits.
There is a possibility of developing vapor lock when aircraft are parked in hot weather conditions. A Rotax 912ULS
aircraft will be more susceptible to vapor lock than a Rotax 912iS equipped aircraft. This condition is worsened after
shutdown resulting in heat building up in the cowling compartment from the hot engine and oil tank. Under these
conditions elevated temperatures may turn fuel into vapor. For this reason, when operating in hot weather conditions
leave the oil door open after shutdown as a means of letting the heat escape. Also, leaving the canopy closed will
elevate temperatures inside the cockpit on a hot day. If possible the canopy should be latched in the mid open position
using the Support Plate Canopy Latch. If it is not possible to leave the aircraft in this condition, extra care should be
taken to open the cockpit, ventilate the cabin, cool objects that may have been in direct sunlight and run the fuel
pump(s) to purge the fuel system of vapor (for more information see the POH Section 4, Normal Procedures).
AIRCRAFT FUELING
See also POH Section 8.3 - FUEL
The fuel tank is designed to be sufficiently vented to allow fueling at fairly rapid rates. Some hoses may be able to
deliver fuel at a high enough rate that the baffling inside the tank in combination with the vent size is insufficient. Use
caution when using high rate of delivery hoses to avoid
“burping” fuel out of the tank and possibly onto the person filling
the tank. As the tank is filled use the mechanical gauge on top of the tank to stay aware of when the tank is nearly full.
Even when the mechanical gauge shows full (due to tank geometry) the tank can still hold more fuel. Slow the fueling
rate and while looking down the filler neck at the fuel level, slowly fill the tank into the base of the filler neck even with
the seal between the tank and the filer neck to achieve the full 20.2 US gallon capacity.
After fueling the aircraft it is important (as instructed in the POH) to remove water and containments from the fuel
system. Water in the fuel may cause engine failure, poor performance, may freeze in the fuel lines as noted above in
cold weather operations etc.
•
For Rotax 912 iS powered aircraft, turning on the boost pump will emulsify the water into the fuel making it
impossible to remove at a gascolator.. Wait until the water and contaminants have settled to the bottom of the
drain line coming from the bottom of the fuel tank then drain them from the fuel system via the sump valve
fitting.
•
For Rotax 912ULS powered aircraft, the fuel pump is located between the tank and the gascolator. First run the
fuel pump for 2 mins, then drain the gascolator to remove contaminants and water. Note the water may be
mixed with the fuel (as shown in the pre-flight section below).