Why does the US use Jet A fuel while the rest of the world uses Jet A1 fuel?

Question

I know the freezing points are slightly different, but that doesn't explain the double standard to me... please explain the reasoning behind the variation. Thanks.

Answer 1

Since no one seems to know the answer, I will offer an opinion. The only differences apparently beween Jet A and A-1 appears to be the freezing point, 7 degrees, and the cost to refine.
Since the aircraft fly in -60 temperature range a lot of the time, all fuel systems are now heated. In the event the heating system failed, it wouldn't be that much of a problem to descend a few thousand feet and get in the -40 range so the fuel wouldn't gel. So, in my opinion Economy and not enough temperature spread are the 2 reasons why we still use Jet A.

Answer 2

Jet A is used in the United States while most of the rest of the world uses Jet A-1. The important difference between the two fuels is that Jet A-1 has a lower maximum freezing point than Jet A (Jet A: –40ºC, Jet A-1: –47ºC). The lower freezing point makes Jet A-1 more suitable for long international flights, especially on polar routes during the winter.

However, the lower freezing point comes at a price. Other variables being constant, a refinery can produce a few percent more Jet A than Jet A-1 because the higher freezing point allows the incorporation of more higher boiling components, which in turn, permits the use of a broader distillation cut. The choice of Jet A for use in the United States is driven by concerns about fuel price and availability.
I'm a Texan, and proud of it!

Answer 3

Just to add a few things to colt's great answer.

Like JET A-1, JET A has a fairly high flash point of 38° C, with an autoignition temperature of 410° F (210° C). Jet A can be identified in trucks and storage facilities by the UN number, 1863, Hazardous Material placards. Jet A trucks, storage tanks, and pipes that carry Jet A will be marked with a black sticker with a white "JET A" written over it, next to another black stripe. Jet A will have a clear to straw color if it is clean and free of contamination. Water is denser than Jet A, and will collect on the bottom of a tank. Jet A storage tanks must be sumped on a regular basis to check for water contamination. It is possible for water particles to become suspended in Jet A, which can be found by performing a "Clear and Bright" test. A hazy appearance can indicate water contamination beyond the acceptable limit of 30ppm (parts per million).

I'm a Detroiter and proud of it!

Answer 4

I can find no reason why the US would not follow international convention.
This may be because the US think they are above all others and don't need to follow convention.
They are the the only country in the world that has not gone metric.
Maybe someone out there has the answer.
And I am standing by to cop a lot of flack from US citizens. ;)
FYI - I am Australian and proud of it. :)

An amendment to countries that haven't gone metric:
Liberia
Myanmar
USA
I should have looked first :(