Discussion:
Aircraft fuel question
Add Reply
Harry Bloomfield Esq
2024-10-17 10:14:40 UTC
Reply
Permalink
When they drain off fuel from the fuel tank, of an aircraft, obviously
that fuel is not put back in the tank - but what is the fuel removed,
then called please, in the world of aircraft?
The Natural Philosopher
2024-10-17 10:25:27 UTC
Reply
Permalink
Post by Harry Bloomfield Esq
When they drain off fuel from the fuel tank, of an aircraft, obviously
that fuel is not put back in the tank - but what is the fuel removed,
then called please, in the world of aircraft?
Why would they drain the fuel?
--
“There are two ways to be fooled. One is to believe what isn’t true; the
other is to refuse to believe what is true.”

—Soren Kierkegaard
Harry Bloomfield Esq
2024-10-17 10:37:32 UTC
Reply
Permalink
Post by The Natural Philosopher
Why would they drain the fuel?
Maintenance perhaps, all I know is that they do, and cannot return the
fuel to the tanks - it has to come fresh, from the bowser..
SteveW
2024-10-17 12:24:17 UTC
Reply
Permalink
Post by The Natural Philosopher
Post by Harry Bloomfield Esq
When they drain off fuel from the fuel tank, of an aircraft, obviously
that fuel is not put back in the tank - but what is the fuel removed,
then called please, in the world of aircraft?
Why would they drain the fuel?
They certainly drain a small quantity of fuel, to ensure that the tank
contains only fuel (and vapour) and condensation has not caused water to
pool at the bottom of the tank and be in danger of being pumped into the
engine(s) in flight.
The Natural Philosopher
2024-10-17 12:43:28 UTC
Reply
Permalink
Post by SteveW
Post by The Natural Philosopher
Post by Harry Bloomfield Esq
When they drain off fuel from the fuel tank, of an aircraft,
obviously that fuel is not put back in the tank - but what is the
fuel removed, then called please, in the world of aircraft?
Why would they drain the fuel?
They certainly drain a small quantity of fuel, to ensure that the tank
contains only fuel (and vapour) and condensation has not caused water to
pool at the bottom of the tank and be in danger of being pumped into the
engine(s) in flight.
Yes I suppose so. Get the water out.
I would expect it to e.g. get reprocessed and sold on as domestic
heating oil.
--
When plunder becomes a way of life for a group of men in a society, over
the course of time they create for themselves a legal system that
authorizes it and a moral code that glorifies it.

Frédéric Bastiat
Harry Bloomfield Esq
2024-10-17 13:12:03 UTC
Reply
Permalink
Yes I suppose so.  Get the water out.
I would expect it to e.g. get reprocessed and sold on as domestic
heating oil.
I only wanted to know, because I was going this morning to a local aero
club, to buy some Jet A1, at 94p per litre. Just a small amount, for my
workshop diesel fuelled heater. Red is unobtainium, despite the law
allowing it, kero 60p perlitre, but only if you buy 500L, otherwise they
want £1.90 or more per litre.

Last week, reading that Jet A1 works, and is near the same as kero, and
others use it successfully, I emailed my local aero club and asked if I
could buy 20L from their bowser. They agreed I could, no problem, just
fill a form in, at the flight desk, pay and collect it.

Then I read something about people getting hold of the waste Jet A1,
even cheaper, and wondered what they might call that waste fuel - hence
my question here.

Whilst at the club, I asked them, and they say what ever they drain,
goes back in the tanks, so 94p per litre it was.

Having now tested it on Jet A1, it was indistinguishable from running on
Tescos white diesel, from the pump, other than the 41.9p per litre saving.
David
2024-10-17 16:09:34 UTC
Reply
Permalink
Post by The Natural Philosopher
Why would they drain the fuel?
I can speak from experience.

The plane I was due to fly on was delayed due to the late arrival of
another flight. The flight crew on the delayed flight were scheduled to
crew my flight.

However, by the time we were able to take off, if the crew had continued
to the ultimate destination, they would have exceeded their hours.

So the airline arranged for the aircraft to land at a intermediate point
where they would do a crew change.

But in order to land at the intermediate point, if they had had their
original load of fuel on board, they would have exceeded their landing
weight.

So they had to offload a certain amount of fuel before we could
take-off. The offloaded fuel was then waste (or more probably went for
recycling)- it could not be used on another flight.
GB
2024-10-17 16:41:07 UTC
Reply
Permalink
So they had to offload a certain amount of fuel before we could take-
off. The offloaded fuel was then waste (or more probably went for
recycling)- it could not be used on another flight.
Are there less mission-critical uses for slightly contaminated fuel? For
example, ground-based electricity generators.
Davey
2024-10-17 16:48:46 UTC
Reply
Permalink
On Thu, 17 Oct 2024 17:41:07 +0100
Post by GB
Post by David
So they had to offload a certain amount of fuel before we could
take- off. The offloaded fuel was then waste (or more probably went
for recycling)- it could not be used on another flight.
Are there less mission-critical uses for slightly contaminated fuel?
For example, ground-based electricity generators.
Maybe that's what my boiler burns!
--
Davey.
Theo
2024-10-17 16:57:24 UTC
Reply
Permalink
Post by GB
So they had to offload a certain amount of fuel before we could take-
off. The offloaded fuel was then waste (or more probably went for
recycling)- it could not be used on another flight.
Are there less mission-critical uses for slightly contaminated fuel? For
example, ground-based electricity generators.
Can you use kerosene in diesel engines? There's various ground tugs,
service trucks, buses etc around the airfield. Although they might not like
fuel additives.

Aircraft have an APU for electricity generation so not sure how much ground
generators you'd need (yes if you're Concorde or a B-52 [*], but not so much
for a 737).

Theo

[*] B-52s can be started with explosives:
https://taskandpurpose.com/tech-tactics/air-force-b-52-cart-start/
The Natural Philosopher
2024-10-17 17:28:37 UTC
Reply
Permalink
Post by Theo
Post by GB
So they had to offload a certain amount of fuel before we could take-
off. The offloaded fuel was then waste (or more probably went for
recycling)- it could not be used on another flight.
Are there less mission-critical uses for slightly contaminated fuel? For
example, ground-based electricity generators.
Can you use kerosene in diesel engines?
It will knock like fuck in a commercial diesel engine.

No compression ignition so it doesn't need anti knock

So depends on what you mean by 'can be used'

There's various ground tugs,
Post by Theo
service trucks, buses etc around the airfield. Although they might not like
fuel additives.
Aircraft have an APU for electricity generation so not sure how much ground
generators you'd need (yes if you're Concorde or a B-52 [*], but not so much
for a 737).
Interesting chart of fuels here.

https://www.nato.int/docu/logi-en/1997/lo-15a.htmo
Post by Theo
https://taskandpurpose.com/tech-tactics/air-force-b-52-cart-start/
--
"When one man dies it's a tragedy. When thousands die it's statistics."

Josef Stalin
jon
2024-10-17 18:17:30 UTC
Reply
Permalink
Post by The Natural Philosopher
Post by Theo
Post by GB
So they had to offload a certain amount of fuel before we could take-
off. The offloaded fuel was then waste (or more probably went for
recycling)- it could not be used on another flight.
Are there less mission-critical uses for slightly contaminated fuel?
For example, ground-based electricity generators.
Can you use kerosene in diesel engines?
It will knock like fuck in a commercial diesel engine.
No compression ignition so it doesn't need anti knock
So depends on what you mean by 'can be used'
There's various ground tugs,
Post by Theo
service trucks, buses etc around the airfield. Although they might not
like fuel additives.
Aircraft have an APU for electricity generation so not sure how much
ground generators you'd need (yes if you're Concorde or a B-52 [*], but
not so much for a 737).
Interesting chart of fuels here.
https://www.nato.int/docu/logi-en/1997/lo-15a.htmo
Post by Theo
https://taskandpurpose.com/tech-tactics/air-force-b-52-cart-start/
My G-wagon had a 3 litre 5 cylinder Mercedes diesel engine with "Indirect
Injection" and it would run on all sorts of fuel, including frying fat.
Jethro_uk
2024-10-17 19:57:03 UTC
Reply
Permalink
Post by jon
Post by The Natural Philosopher
Post by Theo
Post by GB
So they had to offload a certain amount of fuel before we could take-
off. The offloaded fuel was then waste (or more probably went for
recycling)- it could not be used on another flight.
Are there less mission-critical uses for slightly contaminated fuel?
For example, ground-based electricity generators.
Can you use kerosene in diesel engines?
It will knock like fuck in a commercial diesel engine.
No compression ignition so it doesn't need anti knock
So depends on what you mean by 'can be used'
There's various ground tugs,
Post by Theo
service trucks, buses etc around the airfield. Although they might
not like fuel additives.
Aircraft have an APU for electricity generation so not sure how much
ground generators you'd need (yes if you're Concorde or a B-52 [*],
but not so much for a 737).
Interesting chart of fuels here.
https://www.nato.int/docu/logi-en/1997/lo-15a.htmo
Post by Theo
https://taskandpurpose.com/tech-tactics/air-force-b-52-cart-start/
My G-wagon had a 3 litre 5 cylinder Mercedes diesel engine with
"Indirect Injection" and it would run on all sorts of fuel, including
frying fat.
Couldn't a Chieftain Tank run on anything ?
SteveW
2024-10-17 21:53:26 UTC
Reply
Permalink
Post by Jethro_uk
Post by jon
Post by The Natural Philosopher
Post by Theo
Post by GB
So they had to offload a certain amount of fuel before we could take-
off. The offloaded fuel was then waste (or more probably went for
recycling)- it could not be used on another flight.
Are there less mission-critical uses for slightly contaminated fuel?
For example, ground-based electricity generators.
Can you use kerosene in diesel engines?
It will knock like fuck in a commercial diesel engine.
No compression ignition so it doesn't need anti knock
So depends on what you mean by 'can be used'
There's various ground tugs,
Post by Theo
service trucks, buses etc around the airfield. Although they might
not like fuel additives.
Aircraft have an APU for electricity generation so not sure how much
ground generators you'd need (yes if you're Concorde or a B-52 [*],
but not so much for a 737).
Interesting chart of fuels here.
https://www.nato.int/docu/logi-en/1997/lo-15a.htmo
Post by Theo
https://taskandpurpose.com/tech-tactics/air-force-b-52-cart-start/
My G-wagon had a 3 litre 5 cylinder Mercedes diesel engine with
"Indirect Injection" and it would run on all sorts of fuel, including
frying fat.
Couldn't a Chieftain Tank run on anything ?
Pretty well, but IIRC they use lower compression than diesel only
engines and are less efficient.

Tim+
2024-10-17 19:39:53 UTC
Reply
Permalink
Post by Theo
Post by GB
So they had to offload a certain amount of fuel before we could take-
off. The offloaded fuel was then waste (or more probably went for
recycling)- it could not be used on another flight.
Are there less mission-critical uses for slightly contaminated fuel? For
example, ground-based electricity generators.
Can you use kerosene in diesel engines? There's various ground tugs,
service trucks, buses etc around the airfield. Although they might not like
fuel additives.
Aircraft have an APU for electricity generation so not sure how much ground
generators you'd need (yes if you're Concorde or a B-52 [*], but not so much
for a 737).
Theo
https://taskandpurpose.com/tech-tactics/air-force-b-52-cart-start/
As could Field Marshall tractors.


FF to 3:30 if you’re impatient.

Tim
--
Please don't feed the trolls
SteveW
2024-10-17 21:51:48 UTC
Reply
Permalink
Post by GB
So they had to offload a certain amount of fuel before we could take-
off. The offloaded fuel was then waste (or more probably went for
recycling)- it could not be used on another flight.
Are there less mission-critical uses for slightly contaminated fuel? For
example, ground-based electricity generators.
I was involved in testing two gas truebine, 24MW generator sets (for
Shell Gannet in the North Sea). They could run on natural gas from the
well, but for startup (and for our testing) they ran on diesel ... we
burned 1/4 million litres of red diesel during testing - peak rate was
120 litres per minute.
Davey
2024-10-17 16:47:47 UTC
Reply
Permalink
On Thu, 17 Oct 2024 17:09:34 +0100
Post by David
Post by The Natural Philosopher
Why would they drain the fuel?
I can speak from experience.
The plane I was due to fly on was delayed due to the late arrival of
another flight. The flight crew on the delayed flight were scheduled
to crew my flight.
However, by the time we were able to take off, if the crew had
continued to the ultimate destination, they would have exceeded their
hours.
So the airline arranged for the aircraft to land at a intermediate
point where they would do a crew change.
But in order to land at the intermediate point, if they had had their
original load of fuel on board, they would have exceeded their
landing weight.
So they had to offload a certain amount of fuel before we could
take-off. The offloaded fuel was then waste (or more probably went
for recycling)- it could not be used on another flight.
Jeez! When I returned from Cape Town, while Apartheid was still in
force, meaning South African Airways flights had to avoid most of
mainland Africa when flying to Europe, we landed at Windhoek to let all
the soldiers off for the Angolan War. Then we refuelled for the long
flight to London, but after waiting for ages at the start of the
runway, we returned to the terminal, as "the wind had changed in our
favour and we were able to offload unnecessary fuel". That must have
gone to waste, then. To top it off (!), after again sitting at the start
of the runway, we returned again to the terminal to load up with fuel,
"as the winds had again shifted". Somebody must have had a busy credit
card that evening.
After all that, we couldn't get to London, we had to stop at Munich in
order to have enough fuel to get to Heathrow.
The whole flight, from Cape Town to London, took 23 hours, and we
never left the aircraft.
--
Davey.
Andy Burns
2024-10-17 10:48:43 UTC
Reply
Permalink
Post by Harry Bloomfield Esq
When they drain off fuel from the fuel tank, of an aircraft, obviously
that fuel is not put back in the tank - but what is the fuel removed,
then called please, in the world of aircraft?
spent?

<https://benzoil.com.au/services/aviation-fuel-removal/#:~:text=spent>
Tricky Dicky
2024-10-17 12:56:59 UTC
Reply
Permalink
Post by Harry Bloomfield Esq
When they drain off fuel from the fuel tank, of an aircraft, obviously
that fuel is not put back in the tank - but what is the fuel removed,
then called please, in the world of aircraft?
I do not know what aircraft fuel is made of but I always feel it smells
like Keroscene
Theo
2024-10-17 13:17:29 UTC
Reply
Permalink
Post by Tricky Dicky
Post by Harry Bloomfield Esq
When they drain off fuel from the fuel tank, of an aircraft, obviously
that fuel is not put back in the tank - but what is the fuel removed,
then called please, in the world of aircraft?
I do not know what aircraft fuel is made of but I always feel it smells
like Keroscene
Jet-A1 is kerosene, used by jets and turboprops. Avgas is used by piston
engines and is roughly leaded 4* petrol.

Theo
The Natural Philosopher
2024-10-17 13:52:03 UTC
Reply
Permalink
Post by Tricky Dicky
Post by Harry Bloomfield Esq
When they drain off fuel from the fuel tank, of an aircraft, obviously
that fuel is not put back in the tank - but what is the fuel removed,
then called please, in the world of aircraft?
I do not know what aircraft fuel is made of but I always feel it smells
like Keroscene
it is kerosene (sp) + special additives.

NATO specifies that jets and diesels must be able to use it
--
There is nothing a fleet of dispatchable nuclear power plants cannot do
that cannot be done worse and more expensively and with higher carbon
emissions and more adverse environmental impact by adding intermittent
renewable energy.
No mail
2024-10-17 19:47:50 UTC
Reply
Permalink
Post by Harry Bloomfield Esq
When they drain off fuel from the fuel tank, of an aircraft, obviously
that fuel is not put back in the tank - but what is the fuel removed,
then called please, in the world of aircraft?
Fuel is sometimes off-loaded to ensure adequate take-off performance if
conditions have changed and performance is limiting, or to ensure
take-off mass is below maximum if the anticipated payload has changed.
AFAIK the fuel is returned to storage in those cases, but it can also be
mixed with diesel for use in airfield service vehicles. Separately,
small samples are drained before flight to check for contamination by
water, or an incorrect fuel upload (i.e. AVGAS uploaded when it should
be AVTUR, or vice versa) ... these samples are either discarded or
(rarely IME) kept for analysis.
AVTUR is close to paraffin. AVGAS has a few grades but the most common
is "100 octane low lead" (100LL) - but "low" relates to what went before
and the lead content is much higher than 4* MOGAS. I would not use 100LL
in a modern car.
Loading...