Go Back  PPRuNe Forums > Aircrew Forums > Military Aviation
Reload this Page >

More KC-46A woes....

Military Aviation A forum for the professionals who fly military hardware. Also for the backroom boys and girls who support the flying and maintain the equipment, and without whom nothing would ever leave the ground. All armies, navies and air forces of the world equally welcome here.

More KC-46A woes....

Old 31st Jan 2019, 17:11
  #821 (permalink)  
 
Join Date: Aug 2014
Location: New Braunfels, TX
Age: 65
Posts: 1,954
Originally Posted by Just This Once... View Post
KenV, you need to stop digging. Nobody 'stretched' the A330 to produce the A330-300 as it was that shape at launch. From memory the MTOW at launch was 210 tonnes and increased to 212 tonnes during the first production run, with one engine variant with a lowly 184 tonnes MTOW. The MTOW continued to grow and these days is 242 tonnes on the -300 and -200, with the latest versions at 251 tonnes. The fuel capacity differs by customer and market, with the MRTT variant making use of all the tank options. The lowest fuel capacity is on the A330-300 'Regional' jet and the highest capacities are available on both the -300, -200 and the most recent variants.

As an aside, it is pretty rare for MTOW of a design not to increase during service and development. I've no idea why you throw information around on a topic that you have little practical knowledge of.

If anyone feels the need to correct my memory of the weight history please do so as my grey matter is always strained.

Tank fits and volumes:


Dueling spec sheets! The spec sheet below shows that A330-300 is longer by about 5 meters relative to -200. It also shows that -200 and -300 have identical fuel capacities. And yes, you are correct, -300 is not a stretch of -200. Airbus went the other way. -200 is a shrink of -300. Mea culpa. But the bottom line is that -300 is longer by about 5 meters than -200. And MRTT is based on -200 and has same fuel capacity as -200, which matches the fuel capacity of the "3-Tank Aeroplane" above, which has a "centre tank." So clearly the inclusion or deletion of the center wing tank is not a distinguishing feature of either the -300 or -200.
KenV is offline  
Old 31st Jan 2019, 17:48
  #822 (permalink)  
 
Join Date: Apr 2005
Location: UK
Posts: 1,860
So now you are repeating what I wrote back at me? You do realise that means you are battling against yourself, again?

Originally Posted by KenV View Post
... made the claim that the Max Take Off Weight (MTOW) of the A330 has "steadily gone up" over the years .... There's not a single source that supports that claim...

Another nice feature is having a tanker that has sufficient fuel capacity to be filled with fuel to its max take off gross weight. In other words, when the mission is just passing or even just moving gas by air, can you fully fill the airplane with just gas? The KC-46 can. According to this guy, the A330MRTT cannot.

And for the record, USAF tankers have the capability to be filled with fuel to their Max Take Off Gross Weight (MTOGW). It's a standard feature on USAF tankers, even the KC-10 which has a significantly higher MTOGW than A330.

A340, which shares the same wing with A330, has a centerwing tank while no A330 has one.
You really struggle with facts; I get that. You don't like source material; I get that too. You like to challenge people by asserting something you have no idea about; I also get that.

But why do it in public?

I don't get that.
Just This Once... is offline  
Old 1st Feb 2019, 00:40
  #823 (permalink)  
 
Join Date: Aug 2014
Location: New Braunfels, TX
Age: 65
Posts: 1,954
Originally Posted by Just This Once... View Post
So now you are repeating what I wrote back at me? You do realise that means you are battling against yourself, again?
You really struggle with facts; I get that. You don't like source material; I get that too. You like to challenge people by asserting something you have no idea about; I also get that.
But why do it in public?
I don't get that.
Wow. Some of you not only take this stuff seriously, but really quite personally. Very well. A few comments:
1. Struggle with facts? Don't like source material? I have no idea if the data you presented was "source material" but as soon as you presented it I a) acknowldeged it, and b) accepted it at face value. I don't understand how that constitutes a "struggle" or "not liking it." Maybe this is a Brit thing, and I'm not a Brit so just "don't get it."

2. Challenge people? Sorry, no. I did challenge the oft repeated implications that:
a) the final USAF tanker RFP was the same as the first
b) the final RFP was for an off the shelf tanker with little or no development
c) the offerors/manufacturers had the power to tell USAF that their stated requirements "weren't needed"
d) that the US taxpayers are burdened with an over budget tanker program
e) that Boeing in some unexplained fashion "stole" the tanker program from Airbus
f) that either tanker is "superior" to the other. In fact they are quite different and satisfy a different set of requirements that the customer must decide best suits their needs. USAF's needs just happen to be better served by KC-46.
g) KC-46 is not any more survivable in hostile airspace than any other airliner based tanker, including the legacy tankers

If challenging these oft repeated false notions is "challenging people", then guilty as charged. But in America we view that quite differently.

3. Concerning this statement of mine which you bolded and therefore presume you have a problem with:
can you fully fill the airplane [A330MRTT] with just gas? The KC-46 can. According to this guy, the A330MRTT cannot.
Your "source material" does not answer this question. So, is Beagle right and the MRTT will reach its MTOW with full fuel and no cargo, or is Just This Once right and the MRTT with full fuel can still accept 10t of cargo? I personally believe it's the latter and said so right in this thread years ago. What say your "source material?"

4. "Why do it in public?" First off I don't "Do it in public" And secondly, I post here mostly for its entertainment value. I do take people's postings seriously, but I don't take them personally. That would ruin the point of it all.
KenV is offline  
Old 1st Feb 2019, 00:59
  #824 (permalink)  
 
Join Date: Aug 2014
Location: New Braunfels, TX
Age: 65
Posts: 1,954
Originally Posted by BEagle View Post
Rather a vague and incomplete requirement - does the platform have to fly 1500nm, offload 50K and then fly 1500nm back? Over what period of time does the platform need to be on station?

1500nm at 500KTAS is 3 hr. Say the burn rate is 5.4 T / hr and alternate requirements are a further hour's burn to tanks dry, then the tanker would need 37.8 T plus whatever time on task was required. With an offload of 50K (22.7 T), that means a tanker on station for an hour would need to have a capacity of around 66 T. Using legacy ex-airline airframes might be a possibility, but the difficult bit would be fitting the boom and associated operator's station.
Since Lockheed and Airbus are proposing to offer A330MRTT to meet this requirement, presumably an A330 sized airframe or larger meets this requirement. The Omegas of this world can offer a converted used A330, probably A340 (which are very cheap cause no one really wants them anymore, and have greater fuel capacity and MTOW than A330) used 777, or used 747. Maybe US Aerospace (the company that offered new Antonov tankers to compete against Boeing and Airbus for KC-X) would also pursue this. It's potentially a pretty big field that Airbus would have to compete against. And have to compete strictly on price.

And FYI, someone claimed that a one hour late proposal arrival was "not material in this case. [KC-X}" In fact US Aerospace's proposal for the KC-X arrived 5 [u]minutes late because the courier delivering it got held up at the entry gate to Wright Pat. Their proposal was rejected and not considered. So yeah, actually quite material.

Last edited by KenV; 1st Feb 2019 at 01:10.
KenV is offline  
Old 1st Feb 2019, 01:25
  #825 (permalink)  
 
Join Date: Aug 2014
Location: New Braunfels, TX
Age: 65
Posts: 1,954
Originally Posted by LowObservable View Post
Stonecipher admits that the MDC-led team's near tail-less aircraft design and complex engine installations were a calculated gamble. The concept included a lift-plus-lift/cruise STOVL configuration. As designed, a forward gas-turbine engine, mounted behind the cockpit, offers vertical lift, while the main power plant provides rear lift and conventional forward thrust. He feels MDC lost because the propulsion concept was considered "higher risk".

He was more or less right, although the source selection authority was probably wrong about LPLC and there were other undesirable aspects to the MDC proposal. But that doesn't mean that there was a requirement that JSF be single-engine. "Words have meanings", as someone said a few posts ago, and in the context of acquisition, a "requirement" has a specific meaning.
Interesting. So you're saying that Stonecipher was "probably right" and "incompetent." And FWIW, JSF was an outgrowth of SSF, CALF, MRF, and finally JAST/ASTOVL. CALF, MRF, and JAST were all for single-seat/single engine "low-cost/lightweight fighter" aircraft in the F-16 class. JSF inherited that requirement. And yes, it was a requirement. Stonecipher's "high risk" assessment was correct in that MDC took a huge risk in proposing an LPLC configuration under the assumption that the reviewers would not view the pure lift engine as a true second engine. Their projections showed it would be lighter and probably cheaper than both a gas coupled and shaft coupled lift fan, thus meeting the "low cost / lightweight fighter" goal.. He assumed they would view it the same as they viewed an augmented gas coupled lift fan which was MDC's original configuration. He was dead wrong.

Last edited by KenV; 1st Feb 2019 at 01:50.
KenV is offline  
Old 1st Feb 2019, 06:24
  #826 (permalink)  
Ecce Homo! Loquitur...
 
Join Date: Jul 2000
Location: Peripatetic
Posts: 9,999
https://www.janes.com/article/86037/...-boom-redesign

The US Air Force (USAF) will redesign the problematic boom on the Boeing KC-46A Pegasus aerial refuelling tanker to better accommodate lighter aircraft such as the Fairchild-Republic A-10 Thunderbolt II.

USAF Secretary Heather Wilson said on 24 January that the boom does not disconnect as well from lighter aircraft as it does with heavier aircraft. The service has identified an actuator fix that will make the boom a little more sensitive, and she believes it is likely that the A-10 is the only aircraft affected by this issue.

The A-10 is a lighter aircraft compared with some of the USAF's other aircraft such as transports, bombers, and even other tactical combat aircraft. The Lockheed Martin C-130H Hercules weighs 34,686 kg empty and the A-10 weighs 9,183 kg empty, while the Lockheed Martin F-35A Lightning II Joint Strike Fighter (JSF) weighs 13,290 kg empty.

At Boeing's KC-46A first delivery ceremony, Wilson said that the USAF is paying for the boom redesign as it meets the international standard that the service gave to Boeing. In the deal reached in mid-January over the first delivery, the USAF agreed to pay for the boom fix while Boeing would pay for upgrading the remote vision system (RVS). Boeing is planning both hardware and software fixes to the RVS to allow it to automatically adjust and operate effectively in both the sun's glare and in shadow.

Wilson also said that this boom redesign will be the first programme change in the history of the KC-46A.

ORAC is offline  
Old 1st Feb 2019, 10:30
  #827 (permalink)  
 
Join Date: Oct 2018
Location: Ferrara
Posts: 956
"his boom redesign will be the first programme change in the history of the KC-46A"

is that true?
Asturias56 is offline  
Old 1st Feb 2019, 11:26
  #828 (permalink)  
 
Join Date: Nov 2018
Location: Trumpville, on the edge
Posts: 21
At Boeing's KC-46A first delivery ceremony, Wilson said that the USAF is paying for the boom redesign as it meets the international standard that the service gave to Boeing.
So what standard are the current in-service booms on KC135/KC10 designed to? Presumably they don’t have a problem refueling A10 aircraft?
Trumpet trousers is offline  
Old 1st Feb 2019, 12:50
  #829 (permalink)  
 
Join Date: Aug 2014
Location: New Braunfels, TX
Age: 65
Posts: 1,954
Originally Posted by Trumpet trousers View Post
So what standard are the current in-service booms on KC135/KC10 designed to? Presumably they don’t have a problem refueling A10 aircraft?
The boom is designed to the spec in the contract. Sadly that spec was good for every plane except the A-10. USAF screwed up and provided the wrong spec for A-10. That's why this is the "first program change" on the program. Boeing paid for all the previous screw ups and delays. USAF pays for this one.


KenV is offline  
Old 1st Feb 2019, 13:03
  #830 (permalink)  
 
Join Date: Oct 2018
Location: Ferrara
Posts: 956
Thanks Ken - that makes sense now

presumably the USAF lawyers insist that any previous "changes" are in fact a legal duty of Mr B due due to non performance of the original contract

In this case it was the USAF who screwed up so they had to ask for the "change"
Asturias56 is offline  
Old 1st Feb 2019, 13:07
  #831 (permalink)  
 
Join Date: Aug 2014
Location: New Braunfels, TX
Age: 65
Posts: 1,954
Someone asked "When is Boeing going to deliver a tanker that is compliant and that USAF is happy with?" Boeing just delivered two more KC-46, for a total of four. Several more are already built and awaiting government approval to be delivered. USAF can't accept them as fast as Boeing is able to deliver them. As for "compliant" and "happy", yes the delivered aircraft have "deficiencies" but they are compliant. There is a significant difference. The operators/maintainers of the KC-46 are ecstatic. The generals who lead them are very happy. The USAF procurement officials who signed the DD250 and accepted the aircraft are also very happy. So in answer to "when?" It's already happened.
KenV is offline  
Old 1st Feb 2019, 13:19
  #832 (permalink)  
Thread Starter
 
Join Date: May 1999
Location: Quite near 'An aerodrome somewhere in England'
Posts: 25,431
The Omegas of this world can offer a converted used A330, probably A340 (which are very cheap cause no one really wants them anymore, and have greater fuel capacity and MTOW than A330) used 777, or used 747.
There are 2 blindingly obvious reasons why the A340 wouldn't be of much use as a tanker for several aircraft operated by the US.....

Incidentally, only the later stretched -500 and -600 variants have greater fuel capacities than the A340-200/300.

I note that the Luftwaffe is to replace its pair of A340-300 with 3 x A350XWB. Perhaps thought should be given to doing an in-house EFW A310MRTT-style AAR conversion to 2 of them, given that the Luftwaffe has ruled out the F-35 as a Tornado replacement and is considering the Typhoon and/or F/A-18E/F. No boom therefore needed for Luftwaffe requirements.
BEagle is offline  
Old 1st Feb 2019, 13:37
  #833 (permalink)  
 
Join Date: Nov 2018
Location: Trumpville, on the edge
Posts: 21
The boom is designed to the spec in the contract. Sadly that spec was good for every plane except the A-10. USAF screwed up and provided the wrong spec for A-10. That's why this is the "first program change" on the program. Boeing paid for all the previous screw ups and delays. USAF pays for this one.
Are you a politician? Completely worthless response as it did not answer my question!
Trumpet trousers is offline  
Old 1st Feb 2019, 13:48
  #834 (permalink)  
 
Join Date: Jul 2006
Location: The back of beyond
Posts: 1,610
I note that the Luftwaffe is to replace its pair of A340-300 with 3 x A350XWB. Perhaps thought should be given to doing an in-house EFW A310MRTT-style AAR conversion to 2 of them, given that the Luftwaffe has ruled out the F-35 as a Tornado replacement and is considering the Typhoon and/or F/A-18E/F. No boom therefore needed for Luftwaffe requirements.
Wouldn't have really been an issue as Germany has joined the European/NATO multinational MMF programme, using boom-equipped A330 MRTTs.

From Jane's:

Germany, Norway sign for five NATO-owned MRTT tanker-transports

Date Posted: 26-Sep-2017

Author: Gareth Jennings

Publication: Jane's Defence Weekly

Germany and Norway have placed a firm order for five Airbus Defense and Space (DS) A330 Multi Role Tanker Transport (MRTT) aircraft to be fielded under the auspices of the European/NATO Multinational Multi Role Tanker Transport Fleet (MMF).

The announcement by Airbus DS on 25 September came some three months after the two nations formally joined the MMF programme, alongside members Luxembourg and the Netherlands, which had already signed up for two aircraft to be handed over between 2020 and 2022. In addition to the seven MRTTs now contracted, there are options for a further four aircraft should other nations join the programme.

As noted by Airbus DS, the four nations now funding the MMF programme will have the exclusive to operate these NATO-owned aircraft in a pooling arrangement. The aircraft will be configured for in-flight refuelling, the transport of passengers and cargo, and medical evacuation flights.

The Organisation for Joint Armament Co-operation (OCCAR) is managing the acquisition phase of MMF on behalf of the NATO Support and Procurement Agency (NSPA), which will then be responsible for the complete life-cycle management of the fleet.Comment
As previously noted by director of OCCAR, Arturo Alfonso-Meiriño, there is the option for additional countries to join the programme beyond the four that have already signed up. While not named in the announcement, Belgium and Poland have previously declared their interest in a pooled tanker capability.
melmothtw is offline  
Old 1st Feb 2019, 15:30
  #835 (permalink)  
 
Join Date: Aug 2014
Location: New Braunfels, TX
Age: 65
Posts: 1,954
Originally Posted by Trumpet trousers View Post
Are you a politician? Completely worthless response as it did not answer my question!
Oh my. I specifically said the boom is designed to the contract spec. Do you really expect me to post all the minutia of the contract spec? But, in a nutshell, the contract spec references the international axial loading limits for aerial refueling. A-10 is a US-only aircraft and for whatever reason does not appear there. And it has a much lower axial loading capability than the other aircraft. The boom is designed to sense the axial loading and if a parameter is exceeded, do an auto disconnect. USAF screwed up and did not specify this lower axial loading limit for A-10 in the KC-46 contract. Right now, A-10 can indeed be refueled by KC-46 (it's done so numerous times) but without axial loading auto disconnect protection. Boeing will provide a remedy, but at USAF expense.

As for the "KC135/KC10" booms, they are very different in design and operation, including their various protection systems and consequently have different specs. KC-46 uses the KC-10 boom with a modernized version of its axial load limit protection system. The parameters for the KC-46 boom axial load protection system were defined by the contract, which as noted above, inadvertently did not include the lower A-10 load limit. Happy now?
KenV is offline  
Old 1st Feb 2019, 15:50
  #836 (permalink)  
 
Join Date: Aug 2014
Location: New Braunfels, TX
Age: 65
Posts: 1,954
Originally Posted by BEagle View Post
There are 2 blindingly obvious reasons why the A340 wouldn't be of much use as a tanker for several aircraft operated by the US.....
I must be blind because I don't see what those reasons are. Care to elucidate?

I note that the Luftwaffe is to replace its pair of A340-300 with 3 x A350XWB. Perhaps thought should be given to doing an in-house EFW A310MRTT-style AAR conversion to 2 of them, given that the Luftwaffe has ruled out the F-35 as a Tornado replacement and is considering the Typhoon and/or F/A-18E/F. No boom therefore needed for Luftwaffe requirements.
That'll be a hefty effort. A350 like 787 is a near all composite airplane. There is near zero industry experience in doing significant structural mods on in-service composite aircraft. And there are zero used A350s on the market so the economies of converting an old airframe will not be available. Secondly, the idea of a non boom equipped tanker sounded like a no brainer to the RAF at the time Voyager was specified. I suspect that they're regretting that decision now. Further, if the Luftwaffe tankers want to be fully interoperable with NATO tankers and NATO partner aircraft, a boom would seem to be a requirement.
KenV is offline  
Old 1st Feb 2019, 18:31
  #837 (permalink)  
 
Join Date: Nov 2018
Location: Trumpville, on the edge
Posts: 21
KC-46 uses the KC-10 boom with a modernized version of its axial load limit protection system.
For all the superfluous guff that you posted, this 1 quote almost answers the question... “oh my” indeed...
So is it that difficult to align the performance of the KC46 boom with that of the KC10? Or is that beyond logical thinking and expectations?
What time code do you put on your Boeing timesheet for posting on here btw??
Trumpet trousers is offline  
Old 1st Feb 2019, 18:39
  #838 (permalink)  
Thread Starter
 
Join Date: May 1999
Location: Quite near 'An aerodrome somewhere in England'
Posts: 25,431
You still don't see it, Ken V? Think USN / USMC requirements....

And do stop your patronising "Oh My" and "mmmm..." nonsense - it's so utterly puerile.
BEagle is offline  
Old 1st Feb 2019, 18:59
  #839 (permalink)  
 
Join Date: Sep 2003
Location: UK
Posts: 277
Originally Posted by KenV View Post
Someone asked "When is Boeing going to deliver a tanker that is compliant and that USAF is happy with?" Boeing just delivered two more KC-46, for a total of four. Several more are already built and awaiting government approval to be delivered. USAF can't accept them as fast as Boeing is able to deliver them. As for "compliant" and "happy", yes the delivered aircraft have "deficiencies" but they are compliant. There is a significant difference. The operators/maintainers of the KC-46 are ecstatic. The generals who lead them are very happy. The USAF procurement officials who signed the DD250 and accepted the aircraft are also very happy. So in answer to "when?" It's already happened.
If someone delivered me something that expensive, that late, I think happy would be overstating my position. Relieved maybe.
Bing is offline  
Old 1st Feb 2019, 19:38
  #840 (permalink)  
 
Join Date: Jan 2004
Location: Far West Wessex
Posts: 2,515
So you're saying that Stonecipher was "probably right" and "incompetent."

Nope. I'm saying that while the JSF requirement was written around a single main engine (lift/cruise in the STOVL version) it was to the best of my knowledge agnostic as to how STOVL was to be incorporated - other than requiring that it had to be demonstrated on test rigs and in the air within the schedule, which limited the field somewhat. While it was known that some people on the customer side were strongly opposed to LPLC, there wasn't a requirement that eliminated it. Indeed, the MDC team selected LPLC under a government-funded concept definition and design research contract awarded in Dec 1994, so to argue that the customer specifically ruled out such a solution seems strange.

Last edited by LowObservable; 1st Feb 2019 at 20:01.
LowObservable is offline  

Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

Copyright © 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.