Helicopters - Dumping Fuel
Thread Starter
Joined: Jul 2002
Posts: 1,511
Likes: 0
From: East Midlands
Helicopters - Dumping Fuel
1. Can helicopters dump fuel, even small ones?
2. If they can, in what circumstances would they do so?
I did not think that weight reduction was a factor in helicopter operations.
Thanks in advance
2. If they can, in what circumstances would they do so?
I did not think that weight reduction was a factor in helicopter operations.
Thanks in advance
Joined: Sep 2004
Aviation Qualifications: ATPL(H)
Posts: 2,376
Likes: 879
From: Canada
Not many have the capability that I know of but they do exist.
The French Navy Alouette 11's I saw at Frejus Naval base in the Var region of France in 1988 had the capability.
An example for use - if you were searching for survivors and found them before you had burned off much fuel you could dump fuel to allow you to hoist the survivors aboard.
Alouette II
Only other helicopter I ever saw that could dump fuel was a Court helicopters S-61 in Cape Town SA. which had a belly mounted aux tank that could be jettisoned completely.
Example of use - coming off an offshore helideck - lose a stove - one click - you are 1500 lbs + lighter ( I don't remember the combined numbers for weight of tank and fuel) but it was a big tank and you would be in a much better position to fly away VS ditching the beast in the cold South Atlantic.
As I recall they used to use it to do crew changes on ships transiting around the Cape of Good Hope and they were sometimes a long way offshore.
Only two I ever saw but there must be more.
I am sure someone will be along shortly with better information.
You would probably get better results posting this question on the rotorheads thread.
The French Navy Alouette 11's I saw at Frejus Naval base in the Var region of France in 1988 had the capability.
An example for use - if you were searching for survivors and found them before you had burned off much fuel you could dump fuel to allow you to hoist the survivors aboard.
Alouette II
Only other helicopter I ever saw that could dump fuel was a Court helicopters S-61 in Cape Town SA. which had a belly mounted aux tank that could be jettisoned completely.
Example of use - coming off an offshore helideck - lose a stove - one click - you are 1500 lbs + lighter ( I don't remember the combined numbers for weight of tank and fuel) but it was a big tank and you would be in a much better position to fly away VS ditching the beast in the cold South Atlantic.
As I recall they used to use it to do crew changes on ships transiting around the Cape of Good Hope and they were sometimes a long way offshore.
Only two I ever saw but there must be more.
I am sure someone will be along shortly with better information.
You would probably get better results posting this question on the rotorheads thread.
Last edited by albatross; 1st December 2013 at 07:55. Reason: suggestion.
Avoid imitations
Joined: Nov 2000
Aviation Qualifications: ATPL
Posts: 15,110
Likes: 1,083
From: Wandering the FIR and cyberspace often at highly unsociable times
Military helicopters sometimes need to reduce weight. For example, to pick up an under slung load or to carry extra troops who might need moving in a big hurry. Certainly the Puma HC1 had a fuel jettison system. One of the few times I was tasked to use it was over the jungle to deal with a certain illegal crop. It wasn't normally used because the aircraft was short of fuel even with full tanks.
Joined: Aug 1999
Aviation Qualifications: ATP+Mil
Posts: 4,411
Likes: 83
From: Gold Coast, Australia
Very few machines have a fuel jettison capability, and almost all of them are military in origin. I'm discounting the jettisoning of external tanks, more the plumbing to an external pipe.
As SS says the Sea King has a fuel jettison via a pipe above the tailwheel, which in the original HAS1 (ASW) machine was a smallish diameter with a low flow rate. It was, however, about the same diameter as the arrestor hook on the Bucc. Cue a wind up when Bucc driver chum casually asked what the pipe was for when we were mid Atlantic flying non diversion ops from Eagle.
"That's the mount for our hook when non diversion flying in case we have to make a single engine running landing"
It took 4 hours before the unrelated Sea Vixen drivers were asking when we would be fitting our hooks
As SS says the Sea King has a fuel jettison via a pipe above the tailwheel, which in the original HAS1 (ASW) machine was a smallish diameter with a low flow rate. It was, however, about the same diameter as the arrestor hook on the Bucc. Cue a wind up when Bucc driver chum casually asked what the pipe was for when we were mid Atlantic flying non diversion ops from Eagle.
"That's the mount for our hook when non diversion flying in case we have to make a single engine running landing"
It took 4 hours before the unrelated Sea Vixen drivers were asking when we would be fitting our hooks
Guest
Posts: n/a
Merlin + EC725
Military EH101 has fuel dump (but I think it melts some glue or something). I think the French have a Super Puma which dumps an internal aux fuel tank overboard on a button push.
However, just love the comment that weight reduction wasn't a factor in helicopter operations...probably not if you're just flying rubber dog doo from a to b...but for doing anything useful its great....just pray your master dump shuts when you tell it to.
However, just love the comment that weight reduction wasn't a factor in helicopter operations...probably not if you're just flying rubber dog doo from a to b...but for doing anything useful its great....just pray your master dump shuts when you tell it to.
Joined: Jul 2003
Posts: 464
Likes: 2
From: UK
Wessex used to have a fuel dump ability. It was possible to do a running take off at 14000lbs (normal hover Take off limit 13600lbs) so it gave you the ability to reduce weight to make landing safe particularly after losing and engine.
I only ever was on a flight once where we had to dump fuel prior to being re-tasked to lift a heavy under-slung load just after we had refuelled. To give us out of ground effect performance.
I only ever was on a flight once where we had to dump fuel prior to being re-tasked to lift a heavy under-slung load just after we had refuelled. To give us out of ground effect performance.
Joined: Apr 2005
Posts: 347
Likes: 0
From: Dubai
The S61N was operated with a jettison facility on the North Sea for offshore support, I never flew it but I seem to recollect that it was to improve the en-route performance (or at lease operate as a way Group A En-Route would not be limiting). I could be completely out of the park for the reasons, but I suggest posting this on rotor heads may get a broader (and probably more correct) response!
Joined: Oct 2010
Posts: 74
Likes: 0
From: India
In addition to the 'Normal' phase of operations, the fuel dump system would help a great deal to offload in case of OEI conditions for multi engined helicopters/emergencies where lesser all up mass would facilitate safe conditions.
However, I feel that carriage of additional load or troops is part of flight planning and fuel dumping operations as an alternative to poor planning won't be accepted in most cases.
However, I feel that carriage of additional load or troops is part of flight planning and fuel dumping operations as an alternative to poor planning won't be accepted in most cases.
Joined: Jul 2001
Posts: 1,383
Likes: 1
From: ...in view of the 'Southern Cross' ...
Mmmmm ....
As Dagw00d pointed out ... the Bo105 had a dump system that allowed for all the fuel to be dumped from the 'main' tanks which left only what was still in the supply tanks at the time of the dump ... IIRC it dumped at a rate of 50-100kg/min (or something like that??) ....
I believe the same dump kit components 'could' be fitted to the BK117... but I don't think it was ever certified for use on that airframe.
As Dagw00d pointed out ... the Bo105 had a dump system that allowed for all the fuel to be dumped from the 'main' tanks which left only what was still in the supply tanks at the time of the dump ... IIRC it dumped at a rate of 50-100kg/min (or something like that??) ....
I believe the same dump kit components 'could' be fitted to the BK117... but I don't think it was ever certified for use on that airframe.
Joined: Apr 2001
Posts: 20
Likes: 0
From: uk
The S-61N I flew on the North Sea never had a fuel dump facility. However 1 aircraft (G-ATBJ) operated offshore in India from Juhu, was fitted with dumping from the centre tank to allow a reasonable payload to be carried in the high temps experienced there.
For the same reason all the anti-ice equipment was removed, including the heated windscreens, which became a problem in the monsoon when the screens misted up!
For the same reason all the anti-ice equipment was removed, including the heated windscreens, which became a problem in the monsoon when the screens misted up!
Joined: Jul 2001
Posts: 1,084
Likes: 1
From: the cockpit
Australian Black Hawks were fitted with the Sea Hawk dump system permitting 850lbs a minute dump rate or so. Helps with drift downs and OEI situations plus enables weight shedding for operational reasons as mentioned by several above.
It is in the checklist to consider after an OEI event.
It is in the checklist to consider after an OEI event.
Joined: May 2002
Aviation Qualifications: ATP+Mil
Posts: 18,633
Likes: 1,072
From: Downeast
Most Helicopters with Aux Fuel Tanks have that capability....if you leave the Transfer Pump on too long and vent the Aux fuel over the side after topping off the main tanks.