Fuel jettisoning
Thread Starter
Joined: Feb 2006
Posts: 107
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From: UK
Fuel jettisoning
If the decision to dumb fuel is made are there any restrictions to jettisoning in cruise if permission is obtained? Like over the sea on the way to an alternate airport so as not to waste time in holding. The type is a B744 where Up to 45 min may be needed to reduce to max landing weight.
Thanks in advance for your thoughts.
Thanks in advance for your thoughts.
Joined: Jun 2002
Posts: 336
Likes: 15
From: Dubai
Some places have specific locations. Over the sea is preferable, generally above 5000' is a requirement. Avoid jettisoning whilst descending in the hold and near thunderstorms. I don't see a problem with jettisoning in the cruise and would be the sensible option as most diversions that require jettisoning would be time critical.
Joined: Dec 2003
Posts: 2,349
Likes: 845
From: Tring, UK
Having done it a few times, yes, cruise is likely best. You’re also going to be going much faster (TAS) than low level or holding, so the fuel will be better dispersed as it comes out at the same rate.
Joined: Jun 2001
Posts: 4,835
Likes: 85
From: Boldly going where no split infinitive has gone before..
It takes some common sense planning. The goal is to LAND at or near MLW, NOT achieve MLW at some remote location then transit to the runway. Given that the difference between MZFW and MLW can be not that much, poor planning can leave you in a low fuel state.
I did hear a lot of folk-lore about jettison in the sim- thing like "Don't descend in a hold while dumping- you'll catch up with the fuel and set it on fire", and "Don't dump if there are CBs around- a lightning strike will blow you up".
Sounded like BS and certainly wasn't backed up by any litterature, but i actually got tp train a KC 135 pilot, and they obvioulsy know a thing or two about fuel. He confirmed no such concerns were valid.
I did hear a lot of folk-lore about jettison in the sim- thing like "Don't descend in a hold while dumping- you'll catch up with the fuel and set it on fire", and "Don't dump if there are CBs around- a lightning strike will blow you up".
Sounded like BS and certainly wasn't backed up by any litterature, but i actually got tp train a KC 135 pilot, and they obvioulsy know a thing or two about fuel. He confirmed no such concerns were valid.
Joined: Aug 2015
Posts: 265
Likes: 164
From: Sunnydale
Yet items like that (dump and descend and dump near CB) have made it in to my company’s OMA. If it’s BS where has it come from. I don’t know enough to be able to say to my employer “your OMA is wrong”.
