Something not discussed yet (at least in this thread) is how the tankers will be used in warfighting.
I'm not sure of the criteria for this, but is having more medium tankers better during air operations than fewer large tankers? Is ramp space a consideration when busy air operations are ongoing? Is it better to send out more tankers during combat operations to refuel in more diverse locations, than it is for aircraft to wait in line to fill up at fewer but larger tankers? Since these tankers are going to be used for the next 40-50 years, does the procurement of more F-22s and F-35s (stealthy aircraft) change the way strike packages will be put together? My understanding is that fewer aircraft are used in each strike package when stealth aircraft with precision weapons are used. This seems to suggest that during combat air operations with high sortie rates, that more medium tankers (able to deliver fuel in more diverse locations) would be better than fewer large tankers. Granted when used as a transport, a larger tanker can carry more troops or cargo on each sortie, but a tanker is an absolutely vital asset during combat air operations, therefore selection criteria should favor a tanker's contribution to the warfighting effort over its cargo capability. During a build up to a conflict, the tanker (as a transport) is valuable at moving assets into the theater. But during the conflict, the tanker will be used mainly as a tanker. Also, a long range tanker transporting fuel over long ranges, has an adverse affect on sortie rates, but the capability could be useful at other times. Also, operating costs are a consideration for the military just as they are for anyone else when it comes to plane size. It just costs more to send a larger aircraft when a smaller aircraft can get the job done. Conversely, it costs more to send 2 smaller aircraft when a larger one can get the job done. I honestly don't know details for these criteria, but perhaps the USAF needs a mix of both tankers types. I just wonder, since Boeing has decades of experience with these criteria, if they chose the KC767 because they believed it would be the right size for the warfighter. mfaff, this should answer item 2). In regards to item 1), all of the parts have been certified and fly on other aircraft, and Boeing has mixed parts before (first BBJ, 747 SRS, etc), so I don't really see this as a problem. |
Flight Safety
I'm not sure of the criteria for this, but is having more medium tankers better during air operations than fewer large tankers? Defensively, there are arguments for and against - Tankers are considered HVAAs, and you might increase the number you have to 'defend'; against this is the idea thet the loss of one doesn't take the whole capability away. In the late 80s and early 90s, there was alot of talk of small tankers (VC10/Victor) operating relatively close to the red line, supported by large tankers to refuel the small refuellers further behind the line. Unfortunately, from a UK perspective, we are hamstrung not only by the poor serviceability of tanker assets, but also by the number of crews available - from this last point at least, it follows that fewer is better, but that's what happens when the military is run by accountants! STH Edited for 90s/80s muppetry! |
Flight,
I think your view on how the tankers are used is a good one, but is it the one used during selection? Bear in mind that the EADS tanker is configured for centreline boom and drogue and can have (not certain if they are part of the order) drogue pods on each wing, so double tanking (USN/USA helos and allies) could happen, as well as large offload...this double tanking potential is an advantage over the 767 as proposed, making th enumbers arguement more complex. There is a balance to strike (ho ho) between the 'combat' operations side and actually getting the combat capability to the combat area in the most effective and efficient manner as well as the peace time operational tempo. If we were to consider the 'warfighting' aspect as primary then the 767 is still potentially the wrong aircraft, its too big WRT to its off load capability and airfield performance compared to the A310MRTT; admittedly not offered as in EADS's view the larger airframe offered the better compromise. The A310 would offer, for the overall budget greater numbers of airframes and hence number of refueling points airborne, potentially..and an offload capability that pretty much matches the 767 on a one to one basis, whilst being a smaller plane to locate more diversely etc etc. The answer sadly is that in order to replace the 135 there were two board approaches.. a similar sized unit which replaced the 135 on a one for one basis (not in the order..) or a larger unit that doubled up with increased capacity and so the overall number could be reduced. EADS felt that bigger offered the tanking capacity required as well as something more, whereas Boeing stuck to the tanking requirement....and made a clear call not to offer much more. As for the parts mix, yes they are flying in different airframes and Boeing have made hybrids before very successfully, and as with the boom, offered their massive experience as proof the 'could' do it. But the reality as that Boeing offered a great track record and a design, EADS offered a good track record and a design that was already flying. A fine balance indeed. But the political battle is only just beginning and the actual capabilites and needs of the warfighters will be overshadowed by the political needs of those assigning tax payers dollars to them. |
Boeing Bleats
Way back in the Tanker Saga, when the "Mk.2" RFP was issued, didn't the NG/EADS team comment that it was still so skewed towards the 767 (like RFP Mk.1) that it would not be worth their while to enter such a biased "contest"? Apparently the Committee agreed and then allowed NG/EADS to have some input, after which things proceeded as we now know.
Now Boeing complains that the playing field has been tilted ... well yes, but at least it was then pretty well level - and they still reckoned it was bound to go their way ... Granted they could have then proposed a 777 base, but with curent airline demand, when would production slots have been available? The 767 line has only been kept "open" for the KC version, so they stuck with the "Bitza" (bitsa this 'n bitsa that), and perhaps felt that they could then charge the shut-down costs to Uncle Sam ??? (Just a thought). |
Hi, Anyone know where there is a copy of the USAF RFP for the KC-X, the DOD seem to have taken theirs down!
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Red Herring Cargo
There is hardly a greater freighter than the DC-10 or MD-11, yet the USAF does not use their KC-10A fleet for regularly hauling cargo. The missions of cargo and refueling don't normally coincide. The 767 is an oddball for hauling cargo, so what?
According to Wiki, the KC-135 fleet is largely used in theatre, while the KC-10A are used over the pond. The economics of buying a plane to last for 50 years is laughable. Most of the KC-135 fleet have had two engine changes, from J-57 to TF-33 (from retired 707s) to CFM-56. "As of 2006, the KC-135E fleet is flying an annual average of 350 hours per aircraft and the KC-135R fleet is flying an annual average of 710 hours per aircraft. The KC-135 fleet is currently flying double its planned yearly flying hour program to meet airborne refueling requirements, and has resulted in higher than forecasted usage and sustainment costs. The Air Force projects that E and R models have lifetime flying hour limits of 36,000 and 39,000 hours, respectively. According to the Air Force, only a few KC-135s would reach these limits before 2040, but at that time some of the aircraft would be about 80 years old. The Air Force estimates that their current fleet of KC-135s have between 12,000 to 14,000 flying hours on them-only 33 percent of the lifetime flying hour limit. Nevertheless these aircraft are over 40 years old and maintenance costs are increasing, with airframe corrosion being the worst problem." It's better to put 767-200ERs into semi-retirement at a few hundred hours per year, with total cost undoubtedly under $50 Million each, vs. brand new $200 Million whatevers. There may even be used 737s that fit the mission, or a combination of 737s and 767s. In order of utilization, hauling pax on scheduled ops is normally highest, followed by various cargo ops, and aerial refueling is near the bottom. Fedex and UPS, two of the world's most successful airlines, buy new planes only when used ones are not available for the mission. Fedex has even spent $50 Million a copy to create the MD-10, a DC-10 with MD-11 cockpit. The USAF should contract with Fedex and UPS to take their half-life or third-life 767s and MD-11s, and convert them to tankers. The A330 refueler is supposedly scheduled to replace the KC-10A fleet. The A330F empty operating weight is 109 metric tons and takeoff max is 230t. The KC-10A base DC10-30 EOW is 121t and max 260t. That's in the same league, but not quite a direct replacement. The MD-11 empty operating weight is 113t and max takeoff weight is 286t. Now there's a real fuel farm. GB |
Red Herrings
The economics of buying a plane to last for 50 years is laughable. Most of the KC-135 fleet have had two engine changes, from J-57 to TF-33 (from retired 707s) to CFM-56. Nevertheless these aircraft are over 40 years old and maintenance costs are increasing, with airframe corrosion being the worst problem According to Wiki, the KC-135 fleet is largely used in theatre, while the KC-10A are used over the pond There may even be used 737s that fit the mission The USAF should contract with Fedex and UPS to take their half-life or third-life 767s and MD-11s, and convert them to tankers. The A330 refueler is supposedly scheduled to replace the KC-10A fleet The MD-11 |
Just a thought - B claims lower fuel burn, and so does A. Under take-off load, that may be true for the 767, but A states their A330 burns less at common load. Does that mean, when the A330 offloads enough fuel to equal the take-off qty of the 767, the A330 will burn less than the 767? Discuss...
Cheers, y'all |
Originally Posted by Flight Safety
First, the "frankentanker" argument is pure garbage. Doesn't the A330MRTT use the A340 wing?
If A330MRTT was proposed with A350 or A300 parts, then you could call the argument "garbage" - well actually you couldn't. The argument - that planes assembled from bits of other planes are Frankensteins - would be true. You could call Airbus hypocrites though. |
Originally Posted by MDJETFAN
With The Higher Labor Rates In Europe Vs The Usa In Dollar Terms, I'm Curious To Know How Eads Could Match Boeing's Price Especially Since The Kc-43 Is A Bigger Aircraft.
It may be that given their relative market share in the widebody sector at present, Pratt & Whitney were not able to offer their engine for the Boeing at a similar cost to the booming General Electric did for Airbus, but that would be speculative. It could also be that the strike-threatening unions at Boeing have raised costs, even in the weak US exchange rate, to the point where strike-threatening French unions become competitive - if so, that would be quite an achievement. |
GB, your statements regarding the USAF not utilizing the cargo capacity of the KC10 are, I am afraid to say, tosh. The many 'channel' missions around the Pacific are but one set of examples available. :=
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"Most of the KC-135 fleet have had two engine changes, from J-57 to TF-33 (from retired 707s) to CFM-56."
In actual fact most of the KC-135 fleet have only ever had ONE engine change. 157 Air Guard and Reserve aircraft went through the A-to-E conversion in the 80's, where they utilised the TF-33's and larger tailplanes of retired B-707's, and an entirely seperate programme for USAF KC-135A's which saw 400 or so go from J-57 to CFM-56. I'm unaware of any KC-135's that have gone through all three iterations of available engine (possibly a few of the "queers", you know, "insert another letter in front of the C" jobs!). The air guard are still happily toiling away with TF-33 engined E models, and as far as I know there are no plans for them to receive CFM-56's. |
I don't think there are too many KC-135E models flying anymore. I schedule 3-7 AAR sorties every week as part of the OCU here and we use all units - active, guard, & reserve. I haven't seen a KC-135E in well over a year...I'm not about to say they're all gone, as I don't have that bit of info, but I would at least put them on the endangered species list...
IIRC, my contact list for their scheduling, ops, & CP doesn't have a single KC-135E unit listed (but I'm at home w/o my list & make no claims as to its completeness as a comprehensive tanker listing, perhaps only half the country as we're out West - will try to remember to look tomorrow). I do recall having AAR cancelled over a couple of periods last year as a couple of the units were converting from E-model to R-model - these were primarily ANG units. |
Originally Posted by Flight Safety First, the "frankentanker" argument is pure garbage. Doesn't the A330MRTT use the A340 wing? No. It uses the A330/340 wing. There is no A330-specific wing for non-MRTT aircraft. In fact some might say non-MRTT aircraft are underoptimised. |
As I understand it, the A330MRTT has the A330/340 wing with all the necessary plumbing - but has a pod rather than an engine on the outboard pylon.
This helped considerably with development - and meant that they weren't bedevilled by buffet problems caused by the pod pylon as were Boeing. One of the reasons why the Italian aircraft are so late is the delayed development of the essential wing AAR pod system. The A330MRTT has already trailed and wound its hoses; not sure when wet contact trials start, but they won't be long in coming! |
KC-135 Questions
US Herk hypothesized: "I don't think there are too many KC-135E models flying anymore. I schedule 3-7 AAR sorties every week as part of the OCU here and we use all units - active, guard, & reserve. I haven't seen a KC-135E in well over a year...I'm not about to say they're all gone, as I don't have that bit of info, but I would at least put them on the endangered species list..."
------ Aren't the KC-135E models the first to be replaced by the New and Shiny? To all: if you don't like what Wiki says, you are invited to correct it. They do provide references for the doubters and deeper delvers. Re-engining "All KC-135s were originally equipped with Pratt & Whitney J-57 turbojet engines which produced approximately 13,000 pounds of thrust and, in some conditions, utilized water-injection to boost takeoff power output. In the 1980s the first modification program re-engined 157 Air Force Reserve (AFRES) and Air National Guard (ANG) tankers with the Pratt & Whitney TF-33-PW-102 engines from retired 707 airliners. The re-engined tanker, designated the KC-135E, is 14% more fuel efficient than the KC-135A and can offload 20% more fuel. Only the KC-135E aircraft were equipped with thrust-reversers for takeoff aborts and shorter landing rollouts." "The second modification program re-engined more than 410 with new CFM56 engines produced by CFM-International. The re-engined tanker, designated either the KC-135R or KC-135T, can offload 50% more fuel, is 25% more fuel efficient, costs 25% less to operate and is 96% quieter than the KC-135A..." "Upgrading the remaining KC-135E into KC-135R would cost about three billion dollars, about 24 million dollars per aircraft.[4]. According to Air Force data, the KC-135 fleet had a total operation and support cost in fiscal year 2001 of about $2.2 billion. The older E model aircraft averaged total costs of about $4.6 million per aircraft, while the R models averaged about $3.7 million per aircraft. Those costs include personnel, fuel, maintenance, modifications, and spare parts [5]." ---- OK, so each KC-135R did not get a double engine upgrade, but there have been two upgrades. ---- Replacing the KC-135 "As of 2006, the KC-135E fleet is flying an annual average of 350 hours per aircraft and the KC-135R fleet is flying an annual average of 710 hours per aircraft. The KC-135 fleet is currently flying double its planned yearly flying hour program to meet airborne refueling requirements, and has resulted in higher than forecasted usage and sustainment costs.[9]" "The Air Force projects that E and R models have lifetime flying hour limits of 36,000 and 39,000 hours, respectively. According to the Air Force, only a few KC-135s would reach these limits before 2040, but at that time some of the aircraft would be about 80 years old." "The Air Force estimates that their current fleet of KC-135s have between 12,000 to 14,000 flying hours on them-only 33 percent of the lifetime flying hour limit.[10]" "Nevertheless these aircraft are over 40 years old and maintenance costs are increasing, with airframe corrosion being the worst problem." -------- Please describe a typical AAR mission, US Herk, in terms of number of hookups and total fuel transfered. Do you often need the additional tonnage of the KC-10A? GB |
Is it a Military Mission, or just a Flying Club?
Replacing the KC-135 fleet with 15 year old airplanes such as 767s, or A310s at a fraction of the cost of new, and keeping them ten years, makes economic sense. An astute enterprise demands payback within three years, often less.
Planes designed for the military are often worn out or obsolete in several thousand hours. Well built commercial airliners such as the DC-10 are flying over 100,000 hours. The USAF should take advantage of that robustness for a replacement tanker, and buy airframes that have half their usable life and the majority of their cost behind them. Spending $200+ Million for a New and Shiny airplane is folly when used can be had for a quarter of the price. The USAF should be run like a business, not a taxpayer funded flying club. How are the old A310s holding up? GB |
Graybeard
You make an interesting point. However, the great unknown is how many ex-airline 767 / DC-10 / MD-11s are actually available - and the mod state / engine choice / corrosion blah blah - and trying to buy 179 similar aircraft is likely to nothing but increase the price of those second hand jets. So in principle a good idea, but for all the reasons outlined, I think that it is probably a non-starter. S41 |
Originally Posted by Squirrel 41
However, the great unknown is how many ex-airline 767 / DC-10 / MD-11s are actually available
767 = 24 DC10/MD-11 = 11 I suspect that's airworthy/active rather than what may or may not be in deep store/reclamation out in one of the desert boneyards...? |
As of January 2008 the following KC-135 models remained in the inventory
E 114 R 364 T 54 also KC-10A 59 |
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