UK MOD in a muddle over F-35C

spazsinbad wrote:'buddy refuelling' has always meant that the tanker can give away as much fuel as it can spare. A-4s were the first to buddy refuel. There are several old Naval Aviation News amongst other sources about this development in the mid-1950s. The easiest to access online would be Wikipedia or Skyhawk Association so here is one example: [to be clear 'the same type' also means other drogue/probe aircraft].

http://en.wikipedia.org/wiki/Douglas_A-4_Skyhawk

"...The A-4 pioneered the concept of "buddy" air-to-air refueling. This allows the aircraft to supply others of the same type, eliminating the need of dedicated tanker aircraft—a particular advantage for small air arms or when operating in remote locations. This allows for greatly improved operational flexibility and reassurance against the loss or malfunction of tanker aircraft, though this procedure reduces the effective combat force on board the carrier. A designated supply A-4 would mount a center-mounted "buddy store", a large external fuel tank with a hose reel in the aft section and an extensible drogue refueling bucket. This aircraft was fueled up without armament and launched first. Attack aircraft would be armed to the maximum and given as much fuel as was allowable by maximum takeoff weight limits, far less than a full tank. Once airborne, they would then proceed to top off their fuel tanks from the tanker using the A-4's fixed refueling probe on the starboard side of the aircraft nose. They could then sortie with both full armament and fuel loads. While rarely used in U.S. service since the KA-3 Skywarrior tanker became available, the F/A-18E/F Super Hornet includes this capability...."
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Depending on internal fuel that could be transferred (say 3,000lbs of 5,200lbs) an A-4 with three external 2,000lb drop tanks (one being the centreline buddy store) could give away 8-9,000 lbs depending on requirements/conditions.

There are many photo examples of A-4s 'buddy refuelling' much larger aircraft such as this one: http://en.wikipedia.org/wiki/File:A4_RF8A_1960.jpeg
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More A-4 Buddy Store info here: http://a4skyhawk.org/2c/a4parts/html/buddy-store.htm

Almost anything can be set up for buddy store refueling, with a self contained store. A-7s for example were used repeatedly in this role because they were so miserly with their internal fuel, they could hang around with the buddy store for a long time. The KA-3 actually carried an internal fuel tank for "giveaway", but interestingly enough could not use this fuel itself. This caused some awkward situations where a KA-3 would have to declare a low fuel emergency even though it had tons of fuel aboard. There is even a case where a F-8, I believe, about to flame out was plugged into a KA-3 about to flame out when the duo managed to reach a KC-135 which refueled the KA-3 that was refueling the F-8! The later KA-6D could give away its internal fuel and tap its externals, but I'm not sure whether an unmodified A-4 could give away its own internal fuel or tap any of its external tanks for giveaway besides the buddy store itself. As I understand it, its buddy store contained 300 gallons of giveaway fuel, and could transfer at up to 180 gallons /min. This is also the same info given in your skyhawk.org reference, they refer only to the 300 gallons (1908-2040 lbs depending whether you're talking JP 4 or 5) in the buddy store itself. I know someone who absolutely would know and I can contact him if necessary.

In any case, much has been made (by SH proponents) of how the Super Bug has the "added" capability of serving as a tanker. I hope this means it can transfer amongst external tanks and also give away some of its internal fuel. Otherwise it's like any other buddy refueler.

I suspect that since the plumbing and bidirectional pumping equipment isn't there, an F-35 would be just like any other regular aircraft carrying a buddy store, possibly the Cobham 31-301.

'aam' said: "...but I'm not sure whether an unmodified A-4 could give away its own internal fuel or tap any of its external tanks for giveaway besides the buddy store itself. As I understand it, its buddy store contained 300 gallons of giveaway fuel, and could transfer at up to 180 gallons /min. This is also the same info given in your skyhawk.org reference, they refer only to the 300 gallons (1908-2040 lbs depending whether you're talking JP 4 or 5) in the buddy store itself. I know someone who absolutely would know and I can contact him if necessary...."

There is a 4.4GB PDF available that has not only most of the 'how to deck land' info but also a bunch of stuff about Skyhawks, particularly the A4G (RAN FAA version). That PDF has a lot of information about aerial/buddy refuelling with excerpts from an A-4E/F/G NATOPS. As a now very old former A4G pilot (early 1970s) am I expert enough to assure you that the A-4 could transfer internal fuel from wing tanks but not from the fuselage tank which held something like 1,500lbs and a lesser amount in the trainer version. I don't know why that is an issue for you but you have mentioned it. What I have indicated earlier is correct. You can download a free A-4E/F/G NATOPS if you don't want to check my PDFs mentioned. This free NATOPS is my own version scanned by me here:

http://www.gamefront.com/files/user/SpazSinbad
specifically:
http://www.gamefront.com/files/11615952 ... kyhawk_pdf (63Mb)
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04 March 2012 a new version of the 4.4GB PDF about the A4G and RAN FAA aircraft was uploaded to SkyDrive (sadly the file size limit of 100Mb means there are 46 parts):

Folder name is: '__04mar12 A4G FAA 4.4GB Scrapbook PDF'

Copy / Paste the long complete URL below - thanks:

https://skydrive.live.com/?cid=cbcd63d6 ... L0I/TQDzM7 MkWvmGlpc=1&jsref=1&id=CBCD63D6340707E6%21174
OR
SHORT URL: http://alturl.com/z5apg
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There is a free Super Hornet NATOPS available for download, I'm not sure at moment if there is much about air refuelling/buddy stores in that PDF. I'll go and check it later tonight. Meanwhile here is a text snippet from the A-4 NATOPS.
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Here is an interesting (to me) early refuelling pic from those mid 1950s (AFAIK).

http://collections.naval.aviation.museu ... n=16002423

F/A-18-E/F NATOPS may be downloaded here (as well as F/A-18A/B/C/D version:

http://publicintelligence.net/u-s-navy- ... t-manuals/

aaam wrote:

stobiewan wrote:

aaam wrote:

maus92 wrote:Change to F-35B fueled by cost considerations over converting to CATOBAR:

"The UK may have to scrap plans to purchase the carrier variant of the F-35 Joint Strike Fighter and instead revert to ordering the Short Take-Off and Vertical Landing (STOVL) variant due to a lack of funds to redesign the decks of Britain's aircraft carriers, it has been reported."

"While the F-35C airframes are likely to be cheaper and more effective than the F-35B, the estimated £1bn cost of converting the flight deck of the carriers and purchasing EMALS equipment could be too expensive for the Ministry of Defence to afford, according to a report in The Guardian.

Although it has a greater range and the ability to carry a heavier payload, the F-35C design is also said to have suffered from some potentially significant design flaws early in its testing programme, which may push up costs. Late last year a Pentagon report cited concerns at the positioning of the F-35C's arrestor hook and its ability to withstand buffeting, amongst other problems, as a "concern".

Switching away from cat and trap system would also damage Britain's ability to interoperate from French aircraft carriers, as set out in a UK/France defence cooperation treaty and later agreed by the French President and UK Prime Minister David Cameron."

http://www.defencemanagement.com/news_s ... p?id=19037

Some thoughts on the above:

First, I believe that until USMC was directed to buy some F-35Cs instead of some of the Bs it wanted, the C was more expensive than the B.

The range difference s isn't as big as you'd think, because a CTOL has to carry a much larger fuel reserve in shipboard operations than a STOVL a/c. The CTOLs also wear out faster. The B and C have the same avionics, but the C can carry, ~3,000 lbs. more weapons for a max loadout. OTOH, the B has a better thrust/weight ratio.

I don't see how going to the F-35B would prevent the British from operating from French carriers, but it sure would prevent the French from operating from British ones.

AS far as the costs of converting, they were known at the time of the SDSR, but part of the objective of that exercise was to have an excuse to push the carriers out into the future (and maybe get rid of RN fixed wing altogether). After all, it was known that the UK ships would have no organic tanker capability, a must-have for full deep water operations with CTOLs.

The article is junk - the reference to damaging the ability of the UK to operate from French carriers is a nonsense in that the B model would in fact be far easier to operate off the CdG than F35C, which would almost certainly be unable to operate from the French carrier at anything like a combat weight due to the shorter deck, and the shorter, less powerful cats.

Range difference on the C for the UK is, in RAF hands, considerable - and it's important to recognise that the F35 will end up being a significant chunk of the UK's strike capability - both from land and sea.

From the carriers, yes, we need to sort out something for tanker support - Cobb do something that works, and the F35 has two wet hard points easily capable of taking their kit so it's just a case of clearing the kit for use on F35, not inventing anything new.

The C unquestionably has a substantially greater range when operating from land, but it narrows considerably when operating from sea, which is what the discussion is addressing--unless you're of the RAF camp that would be happiest if Britain builds the world's largest helicopter carriers.

Regarding the tankers and the F-35, yes you could set up a a buddy refueling operation, the development of which the UK would have to fund and for which the USN would definitely be grateful. To set it up as on the SH where the a/c itself can draw from this fuel or give part of its own fuel away would add even more R&D costs for a semi-unique version of the -35C. You got the bucks (pounds, euros, whatever)?

Tanker wise, the F35C has two external hardpoints capable of carrying the existing Cobb buddy/buddy systems used by the F18, the hard points are wet.

That leaves the question as to if the UAI system can define fuel flow on the F35, and allow it to both flow from and into tanks, or if the existing management systems already does that.


If it didn't and the tanker had to troll around with only the fuel in the stores, that'd give them about 6,000 lbs to give away.

In other words, the stores exist, F35 can technically carry them - that leaves the task of clearing them for flight and testing them.

Written Answers to Questions Tuesday 10 January 2012 Defence

http://www.publications.parliament.uk/p ... 0w0001.htm

Aircraft Carriers
Angus Robertson: To ask the Secretary of State for Defence what assessment he has made of the current catapult and trap design for the Queen Elizabeth class aircraft carriers and the compatibility of the F-35C aircraft with its main 7.1 foot landing gear to arrestor hook distance. [87594]

Peter Luff: Our investigations into the conversion of the operational Queen Elizabeth class aircraft carrier are still ongoing, but it remains our intent that the catapult and arrestor gear equipment to be installed will be fully compatible with the more capable F-35C strike fighters.

Angus Robertson: To ask the Secretary of State for Defence what comparison he has made of the size of the traps planned for the (a) Queen Elizabeth class and (b) Gerald Ford class aircraft carriers. [87595]

Peter Luff: Our investigations into the conversion of the operational Queen Elizabeth class aircraft carrier are still ongoing, but at this stage, the arrangement and size of the arrestor gear system is the same as that used in the Gerald R. Ford aircraft carrier. However, the exact arrangement of components and sub-systems will differ due to the differences in ship size and compartment layout.

10 Jan 2012 : Column 7W
Alison Seabeck: To ask the Secretary of State for Defence whether he has received an interim report on the carrier variant conversion investigation; and if not, when he expects to receive such a report. [88562]

Peter Luff: Investigations into the conversion of the Queen Elizabeth Class Aircraft Carrier to operate the Carrier Variant of the Joint Strike Fighter are due to conclude in December 2012. The project team is continuing to mature and develop information, in conjunction with UK industry, which will be used to inform decisions on the final conversion solution. Ministers are routinely updated on the progress of this investigation.

As part of the Ministry of Defence approvals process, Ministers will be presented with the Department's full findings to allow them to consider the conversion options and take final decisions."

aaam wrote:I suspect that since the plumbing and bidirectional pumping equipment isn't there, an F-35 would be just like any other regular aircraft carrying a buddy store, possibly the Cobham 31-301.

The one that always perplexed me about the f-35 is why nobody thought to fit the centerline and bay pylons for fuel piping. With only two wet pylons, it severely limits the F-35's usefulness for buddy tanking.

The centerline capability is too small due to the opening bay doors. The outer wing pylon are also limited to 2500 lbs (too small for a 450 gal tank) .

I have no idea about how the F-35 might be able to transfer fuel for buddy fuelling (how much internal fuel could be transferred for example) but anyway here is an idea for the F-16 which may have an application for F-35?

Extra fuel on weapon stations By Arie Egozi on August 8, 2011

http://www.flightglobal.com/blogs/ariel ... tions.html

"An Israeli company has developed a concept that it claims will allow fighter aircraft to carry additional fuel tanks on their weapon stations.

The FAR Technologies concept is based on utilizing military aircraft weapon stations (on the F-16: stations 3 and 7), and adapting them to carry fuel tanks.

Through this the aircraft's mission envelope is extended, and its operational capabilities expanded...."

MORE at the JUMP!

Interesting factoid (a not so good version of Windows?):

Sargent Fletcher ART/S Pod – F-16 VISTA

http://airrefuelingarchive.wordpress.co ... -16-vista/

"...The program was also notable for the development of Direct Voice Input and the “Virtual HUD”, which were both eventually to be incorporated into the cockpit design for the F-35 Lightning II. The STOVL F-35 variants also incorporate MATV [Multi-Axis Thrust-Vectoring (MATV)] while hovering to provide attitude control."

spazsinbad wrote:I have no idea about how the F-35 might be able to transfer fuel for buddy fuelling (how much internal fuel could be transferred for example) but anyway here is an idea for the F-16 which may have an application for F-35?

Extra fuel on weapon stations By Arie Egozi on August 8, 2011

http://www.flightglobal.com/blogs/ariel ... tions.html

"An Israeli company has developed a concept that it claims will allow fighter aircraft to carry additional fuel tanks on their weapon stations.

The FAR Technologies concept is based on utilizing military aircraft weapon stations (on the F-16: stations 3 and 7), and adapting them to carry fuel tanks.

Through this the aircraft's mission envelope is extended, and its operational capabilities expanded...."

MORE at the JUMP!

Well, clean, an F35 is carrying more fuel than an F16 with two external drop tanks. That's 18,000 lbs of fuel - and remember, most of what the UK wants will be a quick hit to provide an aircraft time to go around, wait for the decks to clear, and the very occasional divert if the decks are totally fouled.

I think the 31-301 store carries 1,136 litres of fuel, so that's what, 4000 lbs of fuel in total plus the internal 18,000 on tap? You need a chunk of it for flying the tanker and landing it again but the total fuel is more than the EF/18 which is currently doing the job on USN carriers right now.

I think what is not clear is the question whether some of the F-35C internal fuel is available for transfer to another aircraft. Perhaps it is and that will be good.

Possibly an X-47B will have tanker capability by the time the CVF/F-35C combo requires them.

U.K. Reviewing Lockheed’s F-35B Model, U.S. Official Says

By Tony Capaccio and Gopal Ratnam - Mar 9, 2012 | Bloomberg

"The U.K. is reconsidering its 2010 decision not to buy Lockheed (LMT) Martin Corp.’s F-35B jet, said U.S. Navy Vice Admiral David Venlet, program manager for the Joint Strike Fighter.

Asked in an interview if the U.K. is again interested in the F-35’s short-takeoff and vertical landing model, Venlet replied: “That is under consideration.”"

"The U.K.’s reconsideration of the F-35B model is a “relatively new development” driven by “national U.K. financial constraints and what it costs” to modify its two future Queen Elizabeth-class aircraft carriers so they could carry the U.S. Navy’s F-35C, Venlet said after a presentation to a Credit Suisse conference on defense programs yesterday in Arlington, Virginia."

"Those modifications to the carriers may include adding catapults, arresting gear and other equipment needed to operate the F-35C, he said. “There is a cost” to making those changes “and I think they are re-analyzing” if they should buy the short-takeoff model instead, Venlet said.

“I have told them at various levels of the government, we are with you whatever you need,” Venlet said."

http://www.bloomberg.com/news/2012-03-0 ... ys-1-.html

"...a cost..." -- yeah like ~$3B US not including life cycle O&S etc.

I'm still keeping my fingers crossed that the U.K. will go back to F-35B S.T.O.V.L. on the first (helicopter) carrier completed. But trying to switch from S.T.O.V.L. to catapults back to S.T.O.V.L. again seems foolhardy to me at this point. And no ones taking into account that the catapult carrier can launch E-2D Hawkeyes easily. The E-2's have been launched off of ski-jumps but I'm not sure how well that well work over the long term on a STOVL carrier.

SpudmanWP wrote:The centerline capability is too small due to the opening bay doors. The outer wing pylon are also limited to 2500 lbs (too small for a 450 gal tank) .

Too small for a large fuel tank, but not for a buddy hose dispenser.