Fuel Temperature

kiteland · 发表于 2011-4-20 20:21:14

Fuel Temperature

Limitations: Max fuel temp +49ºC, Min fuel temp -45ºC or freezing point +3ºC, whichever is higher. Typical freezing point of Jet A1 is -47ºC. If the fuel temp is approaching the lower limits you could descend into warmer air or accelerate to increase the kinetic heating. Fuel temp is taken from main tank 1 because this will be the coldest as it has less heating from the smaller hydraulic system A.

A fuel sampling and testing kit is kept on the flight deck of all aircraft to test for water.

The NG series are prone to "Upper Wing Surface Non-environmental Icing" or "Cold Soaked Fuel Frost" CSFF. This is due to cold soaked fuel causing frost to form on the wings during the turnarounds - even in warm conditions! From July 2004 NGs have been delivered with markings on the upper surface of the wings where this frost is allowable for despatch under the following conditions:

Takeoff with CSFF on the upper wing surfaces is permissible, provided the following are met:

the frost on the upper surface is less than 1/16 inch (1.5 mm) thick
the extent of the frost is similar on both wings
the frost is on or between the black lines defining the permissible CSFF area
the outside air temperature is above freezing(0 C, 32 F)
there is no precipitation or visible moisture at the wing surface (rain, drizzle, snow, fog)