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Very cold fuel A320F

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Very cold fuel A320F

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Old 14th Feb 2018, 06:45
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Very cold fuel A320F

The procedure for dealing with very cold fuel in the A320F is either to increase mach, descend or a combination of both. I was wondering how long it takes to get the fluid to warm up after completing these actions, and how much of an altitude change would be required. Temperature over Labrador -Greenland last night was -68c and the aircraft had been fuelled with Jet A at a very cold US airport.
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Old 14th Feb 2018, 06:55
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4,000’ lower alt will increase the TAT by 7 degrees, and an increase of 0.01 Mach will increase TAT by 0.7 degrees.

I don’t know how long the tanks would take to warm up by this amount though.

I have only once had the -47 degree indication, over Greenland, where the SAT was -72 What temp did your fuel get down to?
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Old 14th Feb 2018, 07:03
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-68 outside air temperature might be lower than the aircraft environmental limit anyway. Check the limitations chapter.
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Old 14th Feb 2018, 07:12
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The aircraft is certified to -70c. The fuel got to -30c. Jet A has an FCOM limit of -36c. We were cruising at FL340
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Old 14th Feb 2018, 07:25
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Sometimes at high latitudes it could be beneficial to climb as warmer air may potentially be above you
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Old 14th Feb 2018, 12:38
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Canít speak for the northern parts but in the winter in the 70s southern latitudes you might need to get below FL300 to get the warmer air as the tropopause is so low.
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Old 14th Feb 2018, 15:31
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Turn on wing deice, worked for the dc10 over russia
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Old 14th Feb 2018, 18:54
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Tried -2000 ft and +0.4 M, as well -4000 ft and +0.2M.

I'd take the second option straight next time. The change was noticeable and quick, let's say 10 minutes.

-2000 AND +0.2 was good enough to stabilize the temperature, without discernable improvement. Doing only one of them was not convincing.

-64 SAT and -41 OUTR TK on A1 grade. Inners -37 and that was the root of it.

Another nasty was the low tropopause with -64 well below the original FL, we got limited by environmental envelope during descent!
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Old 15th Feb 2018, 21:37
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You could turn on all the galley ovens.
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Old 16th Feb 2018, 08:53
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The aircraft is certified to -70c. The fuel got to -30c. Jet A has an FCOM limit of -36c. We were cruising at FL340
Depends on the type and the altitude. It isnít always but a steady -70 Limit.

A 319s limit is -70 from about 32,000ft up.

A 320s limit gets colder with altitude. So at 34,000ft the 320 CEO lowest temp is about -67 depending on how you read the graph. It is only -70 from around 38,000ft.

Last edited by EcamSurprise; 16th Feb 2018 at 09:34.
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Old 16th Feb 2018, 16:37
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One thing you can guarantee with Airbus is that no two are the same and reference to the Fcom limits for that airframe is the only sensible option
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Old 16th Feb 2018, 18:15
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Turn on wing deice, worked for the dc10 over russia
You need to be careful using wing anti-ice above it's certified altitude, unless the airframer has previously approved it. Wing anti-ice takes quite a bit of bleed air, and on some installations using that much addition bleed at cruise altitudes can cause problems with engine operability (e.g. it won't accel) and/or cabin pressurization (not enough bleed air to maintain cabin altitude).
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