YS-11 fuel panel

1. | Fuel quantity indicators. Note: There are two F markings in each gauge. The first is for auxiliary wing tank and the other is for the main wing tank.
2. | Fuel Quantity Select switches. These switches select whether the amount of fuel in either the auxiliary tank or in the main tank is displayed.
3. | De-Ice Controls. These control the different anti-ice systems onboard. From left they are Pitot Heat, Prop de-ice (both props), Structural de-ice, No.1 (left) engine de-ice and No.2 (right) engine de-ice. Note: In normal conditions only the Pitot Heat is used. The different de-ice systems use engine bleed air for de-icing thus reducing available engine power, therefore they are only used in conditions where icing is evident.
4. | Fuel Heater Controls. These consist of two switches that control fuel deicing, one for each engine, and a single indicator light below each fuel deicing switch. This light illuminates when the pressure difference in the fuel filters is greater than 3.75 PSI, which suggest a clog in the fuel filters probably caused by an accumulation of ice. Each switch has three positions, which are from the top:
Manual | Fuel heaters are always on.
OFF | Fuel heaters are always off.
Auto | Fuel heaters are turned on automatically when the fuel pressure in the fuel filter differs more than 3.75 PSI. When pressure difference once again drops below 3.75 PSI the heaters are automatically turned off.
Note: Using fuel heaters will reduce the available power by approximately 5% Ys11 operations manual states that: "If the indicated fuel temperature is below 5C or the outside air temperature is below -15C, in case of airplanes not equipped with the fuel temperature indicators, keep the fuel filter deicing switch in "MANUAL"". For approach and landing, the manual recommends keeping the fuel-deicing switch to "MANUAL" for 2 minutes within 5 minutes before landing and then turning off the fuel filter deicing switch. (Fuel-deicing is recommended to be turned off before landing because it limits the available engine power in case of a go-around) However, in 1982 a Reeve Aleutian Airways YS-11A was forced to make emergency landing on to a frozen river under extremely cold weather conditions (-25°C): "The National Transportation Safety Board determines that the probable cause of this accident was the loss of power in the right engine due to the freezing of water in the fuel filter after the fuel heaters were turned off in accordance with the before-landing checklist" Source: NATIONAL TRANSPORTATION SAFETY BOARD, Aircraft Accident Report, Reeve Aleutian Airways Nihon YS-11A, N169RV MNG SALMON, ALASKA FEBRUARY 16,1982 NTSB-AAR-82-14 Important: When the outside temperature drops below -20°C the amount of ice forming increases rapidly, under these conditions it is recommended to keep the fuel deicing switch always on "MANUAL". If the outside temperature is warmer than -20°C the recommendations given in the operations manual are adequate and should be followed.
5. | W/M quantity indicator. Displays the amount of W/M solution available in gallons. Note: The capacity of the W/M tank is about 108 gallons.
6. | W/M Refill Pump switch. Engages the refill pump for the W/M tank. Note: The refill process can only start when the aircraft is stationary on the ground and the high-pressure fuel cock levers for each engine are in either "OFF" or "FEATHER" positions. An indicator light on the right illuminates when W/M refueling is in progress.
7. | Door controls. Use these two switches to open and close passenger and cargo doors. Please note that cargo doors are not available on all models. The main door switch will also automatically deploy the air stairs when available.