FSTA-When?
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The E3 does have a probe for AAR from RAF tankers but... It is not allowed to use the probe to refuel from other coalition tankers. For example, it uses only the boom behind USAF tankers. Does that mean that RAF and NATO E-3s retain the probe ONLY to maintain compatibility with the RAF's centre-line hoses and, if so, at what cost? The USAF E-3s don't have a probe of course.
IMHO the best compromise on the tanker is a recepticle for rcvr AAR, a boom and 2 wing pods. And if you have money to spare - add a centreline hose for redundancy (and legacy heavy rcvrs).
The absolute worst case scenario for a tanker platform would be wing pods only, no rcvr capability and leasing it through a PFI with a non-negotiable contract covering 27 years. I'd rather hang AAR pods under the bellies of our fast jets and let them buddy refuel each other.
IMHO the best compromise on the tanker is a recepticle for rcvr AAR, a boom and 2 wing pods. And if you have money to spare - add a centreline hose for redundancy (and legacy heavy rcvrs).
The absolute worst case scenario for a tanker platform would be wing pods only, no rcvr capability and leasing it through a PFI with a non-negotiable contract covering 27 years. I'd rather hang AAR pods under the bellies of our fast jets and let them buddy refuel each other.
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D-IFF. The buddy-buddy idea which was great as a safety idea for the navy is of little use in a deployment and is very wasteful in a tactical situation. I assume, if a decision is ever made, that some of the FSTA aircraft will still be fitted with centreline hoses since there will be probe fitted multi-engine aircraft, including the A400m, on the inventory for many years to come.
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Art, I understand that the party line is indeed that "some of the FSTA aircraft will still be fitted with centreline hoses" but cannot find anywhere how many "some" is.
Buddy refuelling was the next most ridiculous solution I could think of, after the PFI. I can't think of a more ridiculous solution.
If Paddy hasn't bought them all there are still some DC-10-30s available, at around $4.5million each (http://www.aviatorsale.com/Large_Transport_Jet/). anyone want in?
Buddy refuelling was the next most ridiculous solution I could think of, after the PFI. I can't think of a more ridiculous solution.
If Paddy hasn't bought them all there are still some DC-10-30s available, at around $4.5million each (http://www.aviatorsale.com/Large_Transport_Jet/). anyone want in?
Arters, very sage comment! As one would only expect from one of your years and experience in the AAR game.
One thing which might be considered, perhaps, is a podded centreline hose? We're seeing up to 1250 kg/min from the 907 pod, so rather than the more massive centreline hoses of the past, such as the Mk17 HDU, perhaps a pod mounted slightly off-centre (to avoid the need for additional Vmu testing etc) might suffice for the UK requirement.
Incidentally, many years ago we did suggest to the (retired) BJP that a boom would be a good idea - if only to guarantee a 3rd flight deck occupant! Because, at the time, the RAF was looking at only having 2 pilots to fly the 'Future Tanker'....
If the FSTA ever becomes reality, some form of centreline hose on 'a number' of aircraft is clearly essential. But TriStar experience would indicate that the ability to operate in the receiver role is not essential.
One thing which might be considered, perhaps, is a podded centreline hose? We're seeing up to 1250 kg/min from the 907 pod, so rather than the more massive centreline hoses of the past, such as the Mk17 HDU, perhaps a pod mounted slightly off-centre (to avoid the need for additional Vmu testing etc) might suffice for the UK requirement.
Incidentally, many years ago we did suggest to the (retired) BJP that a boom would be a good idea - if only to guarantee a 3rd flight deck occupant! Because, at the time, the RAF was looking at only having 2 pilots to fly the 'Future Tanker'....
If the FSTA ever becomes reality, some form of centreline hose on 'a number' of aircraft is clearly essential. But TriStar experience would indicate that the ability to operate in the receiver role is not essential.
I understand that the party line is indeed that "some of the FSTA aircraft will still be fitted with centreline hoses" but cannot find anywhere how many "some" is.
Isn't it the nine 'core' aircraft?
Isn't it the nine 'core' aircraft?
I don't think that all 9 core ac will be 3-point.
General McNab, the AMC 4-star, has stated that KC-X is the number one procurement prority in the USAF (JSF was number 3). Furthermore, his list of KC-X "must have" features listed an air-refuelling capability as the 3rd most important attribute. He expanded by stating that they have operated a fleet of 60 tankers that are capable of refuelling alongside a fleet of around 600 that can't - and they are not going to make that mistake again.
It is quite depressing to see how low-spec the FSTA solution is alongside everyone else's new tankers. However, when considered in the context of the (lack-of) funding that the goverment is prepared to allocate to the military, the FSTA really is the best that can be hoped for. Boom, UAARSI or even an entire fleet of 3-pointers is a pipe-dream (geddit!).
Incidentally, the USN have found that buddy-equipped Hornets are useful hose-multipliers when operated with big-wing tankers - which once again proves the old adage of "hoses in the sky".
General McNab, the AMC 4-star, has stated that KC-X is the number one procurement prority in the USAF (JSF was number 3). Furthermore, his list of KC-X "must have" features listed an air-refuelling capability as the 3rd most important attribute. He expanded by stating that they have operated a fleet of 60 tankers that are capable of refuelling alongside a fleet of around 600 that can't - and they are not going to make that mistake again.
It is quite depressing to see how low-spec the FSTA solution is alongside everyone else's new tankers. However, when considered in the context of the (lack-of) funding that the goverment is prepared to allocate to the military, the FSTA really is the best that can be hoped for. Boom, UAARSI or even an entire fleet of 3-pointers is a pipe-dream (geddit!).
Incidentally, the USN have found that buddy-equipped Hornets are useful hose-multipliers when operated with big-wing tankers - which once again proves the old adage of "hoses in the sky".
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Brain, not just Gen McNabb - I heard Gen Mosley make the same statement at a different conference. I Googled "Number one priority for the RAF" but failed to find anything comprehensive. Perhaps it would help if we even knew where our priorities lie?
Art - I stand corrected - doing nothing is the absolute worst case scenario and it appears to be just what is occurring.
Art - I stand corrected - doing nothing is the absolute worst case scenario and it appears to be just what is occurring.
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One thing which might be considered, perhaps, is a podded centreline hose? We're seeing up to 1250 kg/min from the 907 pod, so rather than the more massive centreline hoses of the past, such as the Mk17 HDU, perhaps a pod mounted slightly off-centre (to avoid the need for additional Vmu testing etc) might suffice for the UK requirement.
a la the Indian Il-78 MKI? And I believe the noisy old Tumansky's are being replaced by quieter less thursty jobs?
Yes, that's the sort of thing I was thinking of.
It could also be a potential future upgrade option for the A310MRTT to allow the Luftwaffe to refuel their A400Ms?
I shall be interested to learn how easy it is to prod with an Airbus FBW aircraft - although station keeping of an A330 behind a C-135FR has, I understand, been achieved without any difficulty.
It could also be a potential future upgrade option for the A310MRTT to allow the Luftwaffe to refuel their A400Ms?
I shall be interested to learn how easy it is to prod with an Airbus FBW aircraft - although station keeping of an A330 behind a C-135FR has, I understand, been achieved without any difficulty.
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Beags - you and me both mate! Also, I think it was Brain who pointed-out the question of monitoring a student ('following-through') during rcvr AAR.
I've found little to no info on the development of rcvr capabilitiy so far and, although the current test pilot does have experience of AAR, I'm not sure he is fully up to speed on current techniques, if he is on procedures.
I'm sure the development will be complete before delivery....
On the other hand - it won't matter to the RAF - they'll just need to know how to wind the hoses in and out!
I've found little to no info on the development of rcvr capabilitiy so far and, although the current test pilot does have experience of AAR, I'm not sure he is fully up to speed on current techniques, if he is on procedures.
I'm sure the development will be complete before delivery....
On the other hand - it won't matter to the RAF - they'll just need to know how to wind the hoses in and out!
Quote BEagle: "I shall be interested to learn how easy it is to prod with an Airbus FBW aircraft".
With about 2000 hrs on Airbus FBW types, quite easy I expect. The sidestick works differently to a conventional yolk in that side to side movement selects a bank angle and fore and aft movement selcect a g loading (for those who don't know how it works) but it is still very precise. And the software can be modified to change the handling as required. For example, my company has recently had the flare mode changed in it's A320 aircraft to prevent the aircraft landing long on autolands, and the A319 is now available in a steep approach variety where a button is pressed and glideslopes up to 7 degrees can be flown. There are quite a few flight control software changes involved in that modification. And if that doesn't work, the aircraft could be selected to 'Direct Law' where the stick moves the control surfaces proportionally - as in a conventional aircraft.
With about 2000 hrs on Airbus FBW types, quite easy I expect. The sidestick works differently to a conventional yolk in that side to side movement selects a bank angle and fore and aft movement selcect a g loading (for those who don't know how it works) but it is still very precise. And the software can be modified to change the handling as required. For example, my company has recently had the flare mode changed in it's A320 aircraft to prevent the aircraft landing long on autolands, and the A319 is now available in a steep approach variety where a button is pressed and glideslopes up to 7 degrees can be flown. There are quite a few flight control software changes involved in that modification. And if that doesn't work, the aircraft could be selected to 'Direct Law' where the stick moves the control surfaces proportionally - as in a conventional aircraft.
Hi Dan,
I expect you're correct. However, using the sidestick in the pitch sense to select a g loading rather than a specific pitch attitude might take a bit of learning when following the tanker references (of course you never just chase the basket.....ooh no, deary me no!!) during an approach to contact?
I understand that FCS software modifications in the 'receiver' role are under consideration for the KC-30; however, I don't know whether any decision has been made to incorporate them yet. Perhaps a mode closer to 'Alternate' rather than 'Normal' law?
In the 'tanker' role, a non-linear heading mode can be used to allow gentle entry into turns, then a gentle capture of the 25 deg bank angle, followed by a similar roll-out. Basically this emulates the way we taught people to turn the VC10 using 'MAN' turn mode - so, no doubt to the horror of some, it will be entirely possible to use a HDG/TRK selection when in AAR TKR FLT mode....
Nice jet - as a certain PPRuNer will soon find out
I expect you're correct. However, using the sidestick in the pitch sense to select a g loading rather than a specific pitch attitude might take a bit of learning when following the tanker references (of course you never just chase the basket.....ooh no, deary me no!!) during an approach to contact?
I understand that FCS software modifications in the 'receiver' role are under consideration for the KC-30; however, I don't know whether any decision has been made to incorporate them yet. Perhaps a mode closer to 'Alternate' rather than 'Normal' law?
In the 'tanker' role, a non-linear heading mode can be used to allow gentle entry into turns, then a gentle capture of the 25 deg bank angle, followed by a similar roll-out. Basically this emulates the way we taught people to turn the VC10 using 'MAN' turn mode - so, no doubt to the horror of some, it will be entirely possible to use a HDG/TRK selection when in AAR TKR FLT mode....
Nice jet - as a certain PPRuNer will soon find out
Although the FBW busses have a different control philosophy, one thing that people who have flown them agree on is that the don't feel much different to conventional aircraft. In fact, they have a couple of advantages. First, they are very stable. Second, they don't require trimming. And there is a popular misconception that the side stick takes a bit of getting used to. About 15 minutes seems to be enough - usually!
There is of course the snag there is no connection between the sticks. But that is the case in any phase of flight -just as much in the landing as an approach to a basket. It hasn't caused many problems so far!
A nice jet to fly - as the PPRuNer will discover.
There is of course the snag there is no connection between the sticks. But that is the case in any phase of flight -just as much in the landing as an approach to a basket. It hasn't caused many problems so far!
A nice jet to fly - as the PPRuNer will discover.
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Dan, I have 2 questions about how the FBW systems approximate techniques used in legacy systems. First, does the FADEC have the ability to 'turn itself back on'? i.e. is there a speed, relevant to Vs or GStall when the FADEC might engage itself, even if the a/c is in the direct/basic/normal law? i.e. can you fly at 1.2g stall or 1.15Vs perhaps, for low speed AAR? Second, I'm guessing that, like the C-17 and the F-16, there are simple enough software changes that can be made for an 'AAR mode' for the controls when receiving, but, again in relation to the thrust levers, how easy would it be to make an approach from pre-contact at 1 foot per second, and is there any chance that the FADEC could enter the TOGA range while accelerating?
Just out of idle curiosity of course....
Just out of idle curiosity of course....
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If FSTA will have a centreline hose to allow large aircraft to refuel, will there be enough clearance from the engines, airframe turbulence?
The 767 and A330 will have much larger engines than current RAF platforms, the VC-10 seems ideally configured (not implying it should stay!) and AFAIK the Tristar has to reduce power to avoid issues. Also if they have a higher Max weight will this could create much more turbulence for the receiver? As our other large aircraft are a bit slower, will FSTA have to increase it's AOA? Does anyone use tankers with a similar configuration to FSTA to refuel large aircraft using probe and drogue? The US are the only Force I can think of who routinely refuel large aircraft, I'm guessing the flying boom reduces any power/turbulence issues, I have seen photos of US aircraft hanging a basket off the boom when required, wouldn't this allow much more flexiblity? Will the current FSTA configuration provide the safest and easiest method of refuelling large aircraft, or have we just asked for something like we already use?
I'm sure someone will say of course the companies have done all the calculations, however we have seen the odd howler get through in the past.
The 767 and A330 will have much larger engines than current RAF platforms, the VC-10 seems ideally configured (not implying it should stay!) and AFAIK the Tristar has to reduce power to avoid issues. Also if they have a higher Max weight will this could create much more turbulence for the receiver? As our other large aircraft are a bit slower, will FSTA have to increase it's AOA? Does anyone use tankers with a similar configuration to FSTA to refuel large aircraft using probe and drogue? The US are the only Force I can think of who routinely refuel large aircraft, I'm guessing the flying boom reduces any power/turbulence issues, I have seen photos of US aircraft hanging a basket off the boom when required, wouldn't this allow much more flexiblity? Will the current FSTA configuration provide the safest and easiest method of refuelling large aircraft, or have we just asked for something like we already use?
I'm sure someone will say of course the companies have done all the calculations, however we have seen the odd howler get through in the past.
Ecce Homo! Loquitur...
I have seen photos of US aircraft hanging a basket off the boom when required, wouldn't this allow much more flexiblity?
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I have seen photos of US aircraft hanging a basket off the boom when required, wouldn't this allow much more flexiblity?
So in regards to flexibility, i don't think so. When fitted it can only refuel one type of option, the probe. It has to be removed to use the boom for the recepticle option.
When flying to support a coalition of aircraft using both types of refuelling options then the KC-135 can only be flexible if they use the boom and hose units on the wings... and not the type discussed above.
Last edited by Razor61; 9th Jan 2008 at 15:29.
DIFF idfent.
FADEC is the computer which controls the engines. Thrust manaement is controlled by the Flight Management Guidance Computer (FMGC). The slow speed protection in Normal Law is the Alpha Prot speed (a function of IAS, loading and Alpha). If you get to this point, Alpha Floor kicks in, TOGA thrust is applied (and can't be deselected without turning off the autothrust which will have automatically switched on) and the aircraft will climb like a fart in a bath assuming the autpilot is in. But this happens at a very slow speed - a speed at which a conventional aircraft will be close to stalling - and a speed at which I have never had to fly a tanker. Even refuelling Alberts!
But if it's a problem, I guess it could be changed. It is software and sortware can be re-written.
How easy would it be able to make a slow approach to the basket. Very, I would say. The Airbus thrust levers work like any other if the AT is not engaged. There is a misconception (probably because they don't move by themselves like Boeings) that there is no manual thust control. Of course there is. If you click off the AT or move the TLs out of the detents, manual thrust is what you have. And if the engine response isn't adequate, refer to my previous comment regarding software.
FADEC is the computer which controls the engines. Thrust manaement is controlled by the Flight Management Guidance Computer (FMGC). The slow speed protection in Normal Law is the Alpha Prot speed (a function of IAS, loading and Alpha). If you get to this point, Alpha Floor kicks in, TOGA thrust is applied (and can't be deselected without turning off the autothrust which will have automatically switched on) and the aircraft will climb like a fart in a bath assuming the autpilot is in. But this happens at a very slow speed - a speed at which a conventional aircraft will be close to stalling - and a speed at which I have never had to fly a tanker. Even refuelling Alberts!
But if it's a problem, I guess it could be changed. It is software and sortware can be re-written.
How easy would it be able to make a slow approach to the basket. Very, I would say. The Airbus thrust levers work like any other if the AT is not engaged. There is a misconception (probably because they don't move by themselves like Boeings) that there is no manual thust control. Of course there is. If you click off the AT or move the TLs out of the detents, manual thrust is what you have. And if the engine response isn't adequate, refer to my previous comment regarding software.