Traditionally, the Royal Air Force has used the probe and drogue in-flight refuelling system, contrasting with the US Air Force which uses a flying boom system.
For smaller fast jet aircraft the choice of system makes little difference as under wing pods are easily fitted to most tanker aircraft.
However, for larger aircraft that require higher rates of fuel transfer the choice of system can be a major operational issue. In the past when the United Kingdom has procured large aircraft from the USA such as the E3 Sentry it has converted its aircraft to use the probe and drogue system.
Fitting new fuel systems to aircraft that were not designed to take them can be expensive and time-consuming. With ever decreasing budgets and numbers of aircraft the RAF is increasingly opting to have no in-flight refuelling capability for its large aircraft.
Currently, the RAF operates C17 and RC135 Rivet Joint and Voyager Tankers of which have an in-flight refuelling receiver using only the flying boom system.
In-flight refuelling for large RAF aircraft such as the C130, A400M and E3 Sentry is provided by a high-capacity centre line hose fitted to 7 of the RAF’s Voyager Tankers. Two other Voyagers are fitted for but not with the centre line refuelling point.
The RAF’s Voyager Tanker aircraft is capable of operating with its own flying boom system known as the (ARBS).
Currently, the RAF relies on USAF tankers to re-fuel the RC 135 Rivet Joint and has an MOU with the Air Tanker consortium allowing this. However, if we are ever required to conduct a sovereign operation without American support we may find it difficult to conduct operations.
If, as looks increasingly likely the UK decides to purchase the P8 Poseidon for maritime patrol operations the situation is likely to get even worse. The P8 is relatively short legged compared to the Nimrod and it is highly likely to require in-flight refuelling to be operationally effective, especially in the South Atlantic.
We could take the step to fit the ARBS system to two Voyager aircraft currently fitted for but not with the centre line refuelling system. As far as I can tell, it should not be too difficult to do this even on a finished aircraft. Two tankers would be far from ideal but should allow enough sovereign capability to support our P8’s and Rivet Joints if we are ever required to conduct a sovereign operation.
It would also allow us to better provide support to the USAF.
Given that the A400M can actually carry a high capacity centre line refuelling system with almost no modifications to the aircraft it may make even more sense to convert all 9 Voyagers to use the ARBS system.
In the longer term it is probably far cheaper and easier to convert our tankers over to the ARBS system rather than trying to fit hose and drogue refuelling systems to small fleets of specialist aircraft.
Mark, how is it… what was that you typed? “Assysemetically?” If the unit was installed in the centerline, and a single one at that, how is it asymmetrical? Not to mention if Martin is right, that has been going on for decades, which means that you are bringing up an argument that has been solved for years.
“So there is little reason that our A400M and E3′s could not use the wing mounted pod.”
Well actually there is you get problem from wake shed from the tail of the tanker assysemetrically effecting the receiving aircraft. Not to mention the wing of the larger aircraft getting close to the tail.
Upgrade path is perhaps somthing to consider. Its likely over its life there will be the option of improved engines for P8 at some point giving better fuel eficiency and therefore range.
I can’t imagine the likes of RR and P&W are not constantly working commercially on engine upgrades for the 737 family.
P3 not likely to get that sort of perfromance uplift ever again.
Martin, as a local ex-MPA guy I read every AMSA press release daily, studied the maps and consumed a lot of related news. I saw the P3 and P8 both operating at extreme range (scary extreme) and functionally identical with tasking. That is, when the P3 went and did only 1 hr on task, so did the P8. I wouldn’t have called it for either, but if anything, the P8 will improve at range due to higher transit speeds (/Nav hat off). Don’t be so sure of your opinion.
In terms of P3 and P8 Range I think the hunt for MH370 demonstrated some major issues with the aircraft only getting 2 hours on station.
I doubt we would ever use AAR for such a civilian role but we sure as hell would for a military one. If we are only getting a small fleet of around 5 then we need every force multiplier we can get.
In terms of the KC3 tanker its worth noting that the fuel transfer rate is only 50% higher from the centre line 805 E FRU vs the wing mounted 905 E pods. So there is little reason that our A400M and E3’s could not use the wing mounted pod. Indeed I think this is what they have been doing from our VC10’s for the past couple of decades.
The 805 E FRU is also the same unit that can be installed inside the A400M cargo bay.
I am guessing that the 6 month conversion figure offered by Airtanker is for the KC2 version of voyager that does not already have centre line fuel access and not the KC3 version that does. Either way it can be beyond the means of the MOD to fit two booms on to two tankers already designed to accept them and even just having 2 aircraft equipped like this would give us a major capability boost.
@ Op 3
I think Thompson Holidays is a great use for the spare Voyagers. If we lend the spare capacity to other NATO members then they will not procure additional tankers.
When the s**t hits the fan and we recall all our aircraft for our own use they will have none. It makes a mockery of the concept of having spare aircraft because at the exact time we will need them so will our NATO allies. In effect it means the UK is subsidising other NATO members for AAR.
If in the same situation we have to recall the planes from Thompson then passengers can be easily rooted onto other flights or other civilian aircraft can be chartered. Also given the increased leg room on Voayager vs a Thompson aircraft I doubt there will be any complaints from guests.
@ Thomson
Its worth noting that the F35A actually comes with a probe refuelling variant already as selected by Canada CF35. In terms of a strike Typhoon I think the Tranche 3B aircraft is already the strike aircraft you describe. Typhoon is about as stealthy as a none LO aircraft is ever going to get. Its RCS is rumoured to be around 1 m2 compared to the T50 /PAK-FA that is supposedly 5th generation with an RCS of 0.5m 2
@Observer
I have heard this case about efficiency before.
I understand what you say but in crude terms this is not an exercise I’m proposing spending the money on. In times of need all of the armed forces are prepared to do whatever it takes to be operationally successful; to win.
Not having the right capabilities can often be corrected quickly. Black Buck raid refueling being an example, but we can’t generate all capabilities from thin air. Russia is clearly a menace, it is largely down to Putin, but the State controls the press and the way he manipulates opinion is not healthy.
Protecting our waters, and having the flexibility to deploy and utilise all of our assets effectively is important. For this reason working-time-directive style efficiency speak doesn’t enter my calculations. If I was MoS for defence, I’d need to know my policies cover the eventualities ‘outside natural disaster’. The ‘insurance policy’ needs to avoid Saga by name Saga by nature. Having a sensible requirements specification for our tanker fleet is a good place to start!
@Observer
The best use of tanking an MPA would really be to allow a more aggressive flight profile if needed. You would do something like tank it 2 hours out on its way to station while not expecting it to do much additional time. That would allow for either additional time or if you were doing tricky work you to operate the thing down lower (to stay below radar horizons for example).
Its useful but likely not critical.
Op3, the time limit isn’t only set by the equipment but by the people doing the work as well. Going to the location, staying on station and coming back would be about 8 hours +/-, basically one work shift. You can do more, but efficiency declines the longer you stay out and it affects people badly over the long term if you do it too often. People who get overworked tend to have shorter attention spans, miss things more often and suffer from personality changes, usually for the worse.
Sure, it is useful if you can refuel in mid air for those rare occasions where you’re forced to keep going as there is no one else around and something critically bad may happen, but as a day to day thing, it is best not to overdo it.
There is surely a better market for probe tanker usage than Thomson’s holidays.
The PFI contract is inordinately expensive. I know it is a service but the very notion that the service needs of the Armed Forces can be predicted is ridiculous. Personally I believe we should have a Sovereign capability to deploy all of our armed forces without relying on the goodwill of others. The C17, Airseeker and Voyager fleets all cannot be refueled by our current assets. The P8 is likely to be added to that list.
I’m not saying a probe is a must buy, but I do believe the P8’s need to be able to fly for longer periods than five hours on station. What do we expect our AWACS to do?
@JeremyMH
KC-10 is out of service in next few years, but these additional drogues will be replaced by KC-46 when they come into service.
@All
Fitting booms to some or all of the Voyager fleet would be good but this doesn’t come without cost. Its not just the cost of fitting the booms, but also a significant cost for training boom operators which will add quite a lot to in-service support costs.
Airtanker would love to fit booms, but where is the commercial attraction to do this? They already have massive excess capacity from the Voyager fleet as it is given the large reduction in RAF platforms. They’re trying to get in with the EDA which has a chronic need for more tanker-transports, but this has yet to come off.
@Mark
There is hardly a shortage of drogue equipped tankers in NATO.
The US alone has the following.
59 KC-10’s, all with at least one drogue, 20 with 3.
Around 20 KC-135’s with 2 drogues.
All KC-46’s (170ish) will have one drogue and I think around 40 sets of wing kits are being bought.
Something like 80 KC-130’s.
50 or so MC-130’s (most of these handle air refueling of helicopters but a probe is a probe in the end)
I do agree with you that making the case for a boom based on allied use is kind of silly. The fact is the UK should want the boom for its C-17’s and other such large units it might purchase in the future as well as having the flexibility to purchase things like the P-8 or F-35A without having to make modifications if the government decides it would like to do so. I don’t think its a critical thing for the UK to have but acting as if it wouldn’t be useful is kind of silly. Having a boom in no way precludes you from having 3 drogue refueling points on large tankers. Acting as if a boom in any way limits flexibility is just silly at this point.
It just seems like reasonable flexibility to have given some of the purchases the UK has made and might elect to make in the future. And it really doesn’t cost all that much.
So, just to turn the discussion around, which allies would we potentially be cutting off by not going with boom and socket?
France, Germany, Italy, Sweden and Norway all operate probe and drogue aircraft.
The European boom and socket operators (Belgium, Netherlands, Poland (did they buy ant F-16?), Greece (F-16) and Turkey (F-16) don’t usually conduct out of area ops.
And then there’s the USAF, who are unlikely to deploy *anywhere* without KC-135’s as part of their ORBAT. For a start, they wouldn’t want their major attack elements (B-52, B-1, B-2, F-117(?)) to be “location compromised” by having a foreign AAR requirement somewhere in the chain (even a foreign power with a “special” relationship).
So, in reality we’ll be supporting European / NATO allies that operate the same AAR type as we currently do – and changing to boom and socket would actually be *more* limiting IMHO.
And then there’s the fact that European heavy aircraft manufacturers install probe and drogue AAR by default (Airbus Military, BAE), so moving to boom and socket would effectively tie us into a U.S. procurement choice in the future?
Mark, their boom equipped tankers usually also come with drogues on the MPRS system.
If you want to limit yourself, go ahead. Frankly, my opinion on that is that it ruins your flexibility. A boom can be converted to a drogue and hose. A drogue and hose can’t be converted to a boom. Though the adaptor is rumoured to be very nasty and unforgiving.
Baby got back.
Monkey
Could be wrong but I’ve never heard of aar being operational on p3. Not saying it’s not useful just we prob don’t need it.
Yes I know is an AEW not the MPA but the photo has Vulcan in it ☺
But the MPA MR2 could AAR
Good proposals @martin
Also I really think the RAF should NOT be operating from the Queen Elizabeth-class, leaving it to the Fleet Air Arm to fly their F-35Bs replacing the Harriers whilst the RAF fly F-35As replacing the Tornados (the least compromised variant) and refuel using the BOOM.
But what I’d really love would be if instead of replacing the Tornados with F-35 but with a further developed Typhoon, not how it is now with a secondary strike role but like how the F-15 Eagle became the F-15 Strike Eagle whilst still retaining its air-to-air capability. So it doesn’t lose out in the stealth, avionics, radar and electronic warfare area that all should be further updated like how the F-15 Silent Eagle and EA-18G Growler has been (remember that research the Swiss found about the Typhoon’s EW etc?). The next upgrade is a little bit too far fetched but possible, you tell me, THRUST VECTORING. Eurojet wants to do it and have made a prototype, just needs the funding. The EJ200 is now out of this world as the EJ2x0 Stage 2 with 30% more power than the EJ200 in our RAF’s Typhoons. This further developed Typhoon would be joining the club that can run circles around the F-35 yet strike like the F-35 with the Rafale and Su-35.
Observer
You tell me, about 300 US boom equipped tankers. Yet the Uk is regularly tasked to support US navy and marine corp aircraft because they are all prob refuelled. Holland, Denmark, Norway Belgium about 150 f16s between them and prob no more than 40 deplorable between them. France, Germany, Italy, spain North of 500 aircraft prob equipped and less than 50 tanker aircraft were would you suppose the need might be in a coalition?
@Mark
To have the option to refuel is always use full , that’s why P3 can , P8 can even Nimrod could.
http://www.avrovulcan.org.uk/tankers/571_nimrod.jpg
Mark, that is a strawman argument. If the MPA have been doing their job fine all these years without AAR, then obviously AAR isn’t relevant to them doing their job. You argue that without AAR, MPA can’t do their job, but what has changed? Nothing. Your initial premise *MPAs need AAR to do their job* is itself already wrong.
they regularly stick p3 up to Lossiemouth/kinloss that mustn’t count then. Nor that in the day every NATO nation under the sun stuck mpas in Iceland or the Azores. If p8 can’t do the task without the need for aar then we shouldn’t be buying it.
No Mark – that’s not what I said.
The North Atlantic is a big place and NATO naturally shares out the AO based on geography.
The UK requirement will be defined by the geographic relationship between the UK’s bases and the UK Area of Operations.
The US requirement is defined by a different geographical realtionship becuase their bases and AO are different from ours.
Peter
So an mpa (p3) which has been the mainstay of conducting asw operations in the North Atlantic for the past 50 years is irrelevant to the primary UK requirement to purchase a fixed wing mpa for operations in the North Atlantic?
Mark, think the US counts as a rather big ally to you? And the US may have their own, or maybe not, but without commonality, they’ll simply ask you to go fly a kite as you can’t do a thing for their aircraft. Using a flexible system at least lets them go “Oh, the Brits have a tanker there already, let’s just use that instead of going through the hassle of moving one of our own there.” And there are also the Australians, think you guys are still on good terms with them? Turkey? The Netherlands? Norway? Denmark? Those are all F-16 users in Europe.
Loch, that is true, the MoD writes the requirements. And Airtanker met the minimum required and not a cent more.
If you want to operate with other countries, can’t just look at what you have. You look at what the others have.
Peter E is right, you have to look at what is your ConOps. Most of it unfortunately stems from the simple “go in as a multi-nation coalition”, which means that you must be able to service that “multi-nation coalition” in all its’ variety.
The Voyager PFI has been an expensive disaster, but Airbus, in the latter part of this decade, will start producing a neo enhanced version. Gives us a chance to junk Voyager early (& hang everyone connected with it), then buy a shiny new fleet of A330 neo MRTT, with next generation eco RR engines (14% less fuel?), a combi cabin, freight door, a next generation boom & wing pods.
@Monkey.
If only TD had a like button for comments! :-D
@Observer
“Which is pretty sad because they got you over a barrel like that.”
Is that a barrel of JP-8 ?
Yes it is sad what we signed upto , heho its only till 2035 so plenty of time to think of other options like owning our own f***ing aircraft and using them for our own purposes not flying tourists to Mexico or wherever , like PFI who thought private enterprise would somehow provide a ‘cheap’ alternative to direct funding ? Just an accountants fudge to get round budgetry constraints without having to declare it on this years books but putting a millstone around the taxpayers necks for the next 25 to 50 years .Oh yes the ever so wise Gordon Brown , we have sooo much to thank him for.
(Half need the ability to merge comments for two or more related articles!)
Range of the P-8A isn’t abysmal. Listed publicly as 1,200nmi but can remain on station for fours at this distance. Total 10.5 hours endurance.
Visually, you can expect to be able to remain on station anywhere in this radius for 4 or more hours:
http://www.freemaptools.com/radius-around-point.htm?clat=57.72157899999999&clng=-3.280324999999948&r=2222.50406484889&lc=FFFFFF&lw=1&fc=00FF00&fs=true
“Airtanker chose not to install that particular feature to cut costs, which is a case of the priorities of a for profit company contrasting with the priorities of the military.”
The MoD define the requirement, which is then provided by AirTanker? MoD didn’t ask for a boom.
No observer I’m not. Our c130 are prob refueling as is our a400m and our e3d
Air tanker deliver the requirement defended by the mod. No NATO allies use f15 other than Americans and f16 is used in handfuls out side of Turkey. There’s more prob equipped allies in NATO by a significant margin than boom in Europe.
Mark
Whether we need AAR for P8 does not depend on whether P3 ever needed AAR. It depends on the UK Concept of Ops. Last time is was written this resulted in a requirement for the humungous range of MRA4. But that may have simply been a historical carry over from the range of MR1/2. If we are still working on the same basis then then AAR may indeed turn out to be a requirment to help P8 meet that Concept of Ops.
Alternatively the UK Concept may have been changed to focus more narrowly on the EEZ and the approaches to the Clyde, rather than the wider North and South Atlantic, in which case AAR may not be required.
In either case the past history of the P3 is not really relevant in determing the future UK Requirement.
It wasn’t (purely) to cut costs.
The Centreline 805E unit on the KC3’s has a higher throughput (additional 50%) than the wing mounted 905E pods. Used for refuelling larger aircraft.
You can argue for savings with regards to the KC2, though I think if the wing pods are being used, the centreline fuselage unit doesn’t have the space to refuel a third aircraft.
TOC, I know but still missed in the original blog post and a fairly fundamental bit of info for this particular suggestion. Winking smiley right back atcha.
Mark, you are looking at it too narrowly. Boom AAR is not only for MPA, it is for other aircraft as well. You use C-130s and C-5s do you not?
Apparently the link I supplied above isn’t working, but it showed a list of fairly significant aircraft that can only boom refuel, like the F-15 and F-16, which some of your NATO allies use in fairly significant numbers. Not to mention C-5 and C-130.
A-330 MRTTs can come from the factory with the boom built in, like they did for Australia. Airtanker chose not to install that particular feature to cut costs, which is a case of the priorities of a for profit company contrasting with the priorities of the military. The RAF might want to operate in cooperation with the air force of other countries, but Airtanker only wants to play with the RAF, though I suspect there may be some clauses in their contract for refueling allies in times of need. I do know the reverse is true, if the RAF does not use up a set amount of fuel yet pumps from allied tankers, they are liable for penalties. Which is pretty sad because they got you over a barrel like that.
It wasn’t missed, discussed in the Open Thread at the beginning of the month ;)
General feeling was it was a good opportunity, may also see the introduction of booms, uncertainty whether we’d be clogging up airspace where there are boom equipped tankers already flying a pattern.
All of you have missed the recent news that would, to my mind, provide the only justification in terms of cost/benefit analysis for fitting a boom refuelling system:
http://www.flightglobal.com/news/articles/airtanker-pitches-voyager-for-nato-refuelling-shortfall-402487/
Greater overall contribution to NATO is a valid consideration; but it’s not as if we get a financial reward, just another incremental increase in our overall standing. Which, after all, is what military effect is all about these days – actual fighting power is a second order consideration.
Refuelling helicopters is a non point as I don’t believe the maximum speed for a helo and the minimum stall speed for the Voyager overlap at all. You’d need a C130 or A400 as well as a reason to do it. Besides, long range helo ops are of questionable value given vulnerability and the punishment on the airframe – unless you look at the US Joint Personnel Recovery (CSAR) and deep-strike special ops capability for which you then have a valid model. Since we a) don’t have a CSAR/JPR capability anyway and b) would use CH47 with extended range tanks for that anyway, it remains a moot point.
Martin
The p3 didn’t do aar so does it matter if p8 doesn’t? We seem to be saying change our awac, Astor capability and change or increase our aar training and equipment to get a p8 in the inventory.
Airtanker have stated it would take 6 months to convert one of there aircraft to have a boom at an additional cost.
The standard A330 MRTT as supplied to Australia and Saudi Arabia has a centre line boom and a drogue pod mounted on each wing. The A330 wing is common with the A340 so the pods pick up on the wing structure the would support engines 1 an 4 on an A340.
It should be no particular problem retrofitting RAF aircraft with a boom, unless the centre line hose reel has required major structural rework. Just pay the contractor more.
In any likely conflict tankers tend to become a multi customer asset so the RAF may have put a boulder in its own pack by requiring a RAF specific version of the A330.
@ Mark – I would not disagree that we are happy with our drogue system for tanking fast jets aircraft. Indeed I would go as far to say its the superior system for smaller aircraft. But the issue is using it for larger aircraft.
Right now we can get by but if we by the P8 we need to seriously look at the requirement.
Its worth noting that as far as I am aware there is nothing to stop aircraft like the A400M using the wing pylon mounted drogues on the A330. The fuel rate is slower so it will take longer but I dont think there is a show stopper in it happening.
Martin,
I believe our A330 Voyagers currently do not have UARRSI. This is despite this being a standard feature on the Airbus MRTT. We had ours removed.
Essentially our Voyagers lack two fundamental capabilities
1. Being able to be refuelled in flight
2. Being able to refuel our large aircraft such as the C17, Airseeker and potentially the P8. I might add that the E3 replacement can easily be envisaged being the next plane added to the list.
I’d love to know how long it would take to rectify the above issues in a hurry.
Remember, the probe and drogue system is the only one which works with helicopters.
Most of the time.
https://www.youtube.com/watch?v=X-9MRjeafcU
Peter first off I would ask how many maritime mission extend beyond 10hrs in duration. Then if the p3 has avoided using aar for its entire life so how much is that really a negative. Perhaps best left to allied boom tankers would be my view.
Aircraft with probs include gripen typhoon f35b,c rafale, super hornet, c130, a400m, our awac cn295 not to mention significant mirage varients. Not saying booms are bad we and significant portions of our allies don’t use them. The US has lots of boom refuellers so perhaps we add a niche. Not using a boom does mean no single point of failure on the tanker aircraft for tactical jets.
Mark, that is probably true in the past, but the current trend is sort of leaning towards multi-national cooperative ventures, so interoperatability took a huge jump in importance. Not to say drogues are wrong, they work well, just that situations change and plans change too. With everyone cutting their military, anything of importance that needs to be done now looks to a need for cooperative effort by different countries, which means interoperatability becomes more important.
http://www.japcc.org/aboutjapcc/cis/aarmatrix/Workspacelibrary/AAR_MATRIX/National_SRDs/National_SRD-Singapore.pdf
If you looked at the end, there is a list of aircraft types that are sorted between boom and drogue refueling. (Part 4-1 and 4-2). There are some fairly significant ones that are only boom dependent, like the F-15/16/22/(35?), C-130 etc.
Mark
Do you envisage ‘No UK Requirement’ for booms continuing indefinitely?
In the event that we did procure P8 as an MPA would you prefer us to:
(a) pay to put probes on them
(b) pay to put booms on our tankers
(c) rely on Third Party tanking / do without
Just interested to know your preference.
Peter
Were quite happy with drogue fueling so is the us navy and all our major European allies. US navy uses our tankers a lot.
No uk requirement for booms therefore no booms on the tankers.
I have always found it amusing that this debate is often presented as if the USAF is the only major user of boom refueling.
Just of the model that the UK uses for air refueling 3 of the 4 users use a boom. Among NATO nations I think you see booms on almost as many nations as you don’t at this point given the proliferation of the F-16 and likely proliferation of the F-35A. In the Pacific most major western aligned nations use boom refueling. A lot of nations won’t bother having refueling capability at all I suppose but I never saw the benefit of not having the booms put on considering the UK had aircraft in inventory that could make use of them and it would add flexibility going forward.
But that is a ship that has sailed. You aren’t putting booms on civilian owned aircraft.
[You realize, of course, that if you convert to the ARBS, all your aerial refueling specialists will gain the nickname “Clancy?”]
This one went over my head, sorry.
As for the refueling systems, they are not mutually exclusive, so it is possible to actually have a flying boom in the fuselage and 2 drogue systems on the wings. This would allow all aircraft to use the tanker. The A330 that we are getting from you guys are dual system aircraft made that way by Airbus so it doesn’t seem to be that difficult. The Australians use a dual system too I think. That would give the most flexibility in Coalition tasking as well as future proofing any new aircraft buy since there is no longer a need to convert foreign bought aircraft to a specific system they may not have been designed for.
I’m presuming that maintaining 805E’s on the centreline for some aircraft is desirable for the larger probe refuelling aircraft?
Cobham MRTT Refuelling systems
You realize, of course, that if you convert to the ARBS, all your aerial refueling specialists will gain the nickname “Clancy?”