Flight Safety: Is there any possible way the fuel could been Russian TS-1, which has a freeze point of -57C, min low flash point of 28C, and has properties and test methods similar to Jet A-1?
Russian fuel grades
GOST Standard 10227-86 lists four grades of fuel, TS-1, T-1, T-2 and RT. Each has a category of quality with TS-1 having both a higher and first category, of which only the first category appears to be in use. An update of Table 1 of this specification, listing TS-1, RT and two Military fuels, T-8V and T-6, requires an antioxidant and a lubricity improver in RT, T-8V and T-6. Another amendment noted is a change in the Crystallization Point (similar to our freezing point) in TS-1 and RT to -50 °C with -60 °C and -55 °C respectively being produced by user demand.