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D. FUEL FREEZING LIMITATIONS

D1 INTRODUCTION

On some particular routes, fuel freezing limitations may be a concern. When very low temperatures are expected, the dispatch or flight plan may be affected, and have economical implications. Some routes may not be flown under severe temperature conditions with any fuel type. Similarly, when very low temperatures are encountered in flight, specific crew procedures may be necessary.
This chapter reviews various aspects associated with fuel freezing limitations.

D2 DIFFERENT TYPES OF FUEL

For commercial fuel requirements, (excluding North America, Russia and China), it is primarily the petroleum companies who dictate turbine fuel specifications, due to the variations in national specifications. The Aviation Fuel Quality Requirements for Jointly Operated Systems is a petroleum industry standard which embodies the most stringent requirements of the UK DEF STAN 91/92 and USA ASTM D1655 fuel specifications to produce a kerosene fuel designated JET A1. It is known as the Joint Fuelling System Checklist (JFSCL) and is used by eleven major aviation fuel suppliers for virtually all civil aviation fuel supplies outside of North America, Russia and China.
All civil jet fuels in USA are manufactured to specifications defined by the American Society for Testing and Materials (ASTM). These civil fuels are designated by ASTM as D1655 JET A and JET A1, high and low freeze point kerosene type fuels, and D1655 JET B, wide cut low flash point type fuel. JET A is the principle fuel available in the USA. Jet fuels for use by the U.S. military services are controlled by an U.S. government specification and are given the prefix .JP..
International Air Transport Association (IATA) issued a .guideline jet fuel specification., the main purpose of which is to make specification comparison of jet fuels produced in various countries. The IATA Guidance Material presently defines suitable characteristics for four grades of aviation turbine fuels: JET A, JET A1, TS-1 (kerosene-type fuels) and JETB (wide-cut fuel). These fuels meet the requirements of the following specifications:
. JET A  ASTM D1655-98b (JETA) 
. JET A1  JFSCL (JET A1) 
. TS-1  GOST 10227-86 (TS-1) 
. JET B  CAN/CGSB-3.22.97 (Wide cut type) 

The following fuel types are approved for use on Airbus Industrie aircraft. Some of them are approved for certain models only (refer to FCOM and AFM limitations).
● Kerosene:
This is an aviation turbine fuel type obtained from direct distillation.
Generally, the term .kerosene. is employed to describe a wide range of petroleum,
defined only by a minimum flash point of 38°C and an end point of no more than 300°C.

.
Flash point is the fuel temperature at which sufficient vapor forms at the surface of the liquid for the vapor to ignite in air when the flame is applied.