Fuel Jettison- Altitude constraint

[lion-g]

Hi Guys,

A very happy new to all. Just want to know if there's any rule of thumb that you guys use for MAX altitude for fuel dumping.

I understand that there's a Min altitude for fuel jettison, namely 7000agl winter and 4000agl summer and 10000agl if over water.

Any comments?

Cheers

[Spooky 2]

Where did you come up with those numbers. Not disagreeing with you but wondering your source of information.:ok:

[FE Hoppy]

UK CAA document CAP 493 Manual of Air Traffic Services Part 1


12 Fuel Jettisoning

12.1 Pilots of aircraft in flight are permitted to jettison fuel in an emergency. The decision to jettison rests solely with the pilot but he may request guidance from ATC.

12.2 When an aircraft in controlled airspace needs to dump fuel, ATC should co-ordinate with the flight crew:
a) the route to be flown which, if possible, should be clear of cities and towns, preferably over water and away from areas where thunderstorms have been reported or are expected;
b) the level to be used;
c) the estimated duration of the fuel dumping; and
d) the frequency to be monitored whilst the aircraft is dumping fuel.

12.3 Controllers are to recommend to flight crew that jettisoning of fuel should be carried out above 10,000 feet agl. Exceptionally, if fuel dumping at this level, or over water, is operationally impracticable or inconsistent with safety, fuel may be jettisoned above 7000 feet agl in winter and above 4000 feet agl in summer. For fuel to be jettisoned below these levels the situation must be unavoidable.

12.4 A vertical separation of at least 1000 feet between aircraft should be maintained.

12.5 Adjacent ATC units and control sectors should be informed of the fuel dumping taking place, including co-ordination with units providing services outside controlled airspace where the aircraft’s track is near to the boundary of controlled airspace (both laterally and vertically).

As usual the authorities have chosen to hide this information in their official publications available for free from their website. The swine!

As for max altitude, check your AFM limitations section. If nothing is stated then there is no limit.

[anotherthing]

lion g

you are getting slightly mixed up with your figures and when to use them (from an ATC point of view). Check the post above!!

[zlin77]

Used to be 6,000 Ft. minimum and clear of cloud (Static buildup) in my region.

[Spooky 2]

Thanks FE. Most if not all of the Boeing pubs use 4000' with no further conditions stated. Learn something new everyday around here! :ok:

[FE Hoppy]

Spooky,

Be aware that this is valid in the UK. It may be different in your location.

[lion-g]

Thanks for the prompt reply. Yes, I understand that each ATC region have their own altitude constraints and what I have stated might be applicable in UK only. Sorry for creating this misunderstanding.

What I really what to know if you guys have any ceiling where you can start your fuel dumping .... Say you have an engine failure in flight drifting down to FL300 (EO max alt) .... with the blessing of ATC will you start your fuel dumping on your decent..... assuming all other criteria are met.

Or after completion of ECAM action in a holding pattern at FL250, will you guys consider dumping fuel at that altitude?

A point was brought up during our discussion that dumping fuel at high alt, with low OAT might cause the fuel jettison nozzle to freeze up, which I find it highly unlikely.

Any comments ?

Thank you so much for your time.

Cheers

[411A]

Or after completion of ECAM action in a holding pattern at FL250, will you guys consider dumping fuel at that altitude?

Well....I don't have an ECAM (I have something far superior, a professional Flight Engineer:)) however, yes, I have dumped fuel at FL250, out over the Red Sea.
No problems whatsoever.

[formulav]

Of the four times I have dumped, the only restrictions that I am aware of are speed, configuration, HF's off and ask ATC if they have a preffered area. Thats in a Douglas aircraft. Hope that helps.

[Flight Detent]

Well said 411A.....:ok: