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More KC-46A woes....

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More KC-46A woes....

Old 4th Jun 2016, 09:25
  #461 (permalink)  
 
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I've not seen or heard any evidence of any of the modules of the A330 MRTT MPS being certified for use, but it does appear to enhance SA very well.

The aircraft as a whole though, has achieved around 20,000 boom contacts and offloaded over 100M Lbs of fuel amongst its many operators.

I did hear that Airbus could start rolling A330 MRTTs off the production line after about 2 months of an order, ensuring they could "deliver the tanker well ahead of Boeing". Hard to say what 'Nonconforming' means without any output specifications being written for any specific orders or interim solution.
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Old 6th Jun 2016, 10:16
  #462 (permalink)  
 
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ORAC, beware the danger of posting articles that are years out of date, unless of course you mention the date. I read your link and then discovered it was written in 2013. Not sure now what the situation is with the Dreamliner.
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Old 6th Jun 2016, 10:37
  #463 (permalink)  
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Sharpend, it was posted, in light of early posts, to show a view concerning the change of Boeing management after the merger - not to comment specifically on the Dreamliner.
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Old 6th Jun 2016, 13:48
  #464 (permalink)  
 
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I did hear that Airbus could start rolling A330 MRTTs off the production line after about 2 months of an order, ensuring they could "deliver the tanker well ahead of Boeing". Hard to say what 'Nonconforming' means without any output specifications being written for any specific orders or interim solution.
At the risk of repeating myself - again - the A330 MRTT does not even come close to meeting the USAF requirements as outlined in the RFP. Neither did the KC767, hence the need for a multi-year multi-billion dollar development program.
The idea that Airbus could begin delivering USAF compliant tankers 2 months after an order is laughable.
Now, if you want to question if the USAF really needs all that extra stuff - that's a very good (and very different) question. As I noted earlier, questioning some of the less-sensical USAF requirements was met with a "What part of mandatory don't you understand" response.
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Old 9th Jun 2016, 17:58
  #465 (permalink)  
 
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Boeing has developed a software fix, but don't like the robustness of the solution. They now have a hardware solution similar to the KC-10's load relief system and will be testing it shortly.

LINK
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Old 9th Jun 2016, 18:14
  #466 (permalink)  
 
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Begs the question, if a similar load-relief system is used on KC-10, then why not KC-46 already? Leaving it all to electrons?
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Old 9th Jun 2016, 20:45
  #467 (permalink)  
 
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Should have bought Airbus.... No don't it will be covered up.
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Old 10th Jun 2016, 14:41
  #468 (permalink)  
 
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Begs the question, if a similar load-relief system is used on KC-10, then why not KC-46 already? Leaving it all to electrons?
Yes, that was basically the idea: the new fly-by-wire system that replaced the analog/mechanical flight control system was supposed to provide all the load relief/protection that the dedicated and separate hydraulic load relief system provided. The FBW system worked, but was not "robust enough" (whatever that means) to ultimately satisfy the Boeing engineers, so a dedicated and separate hydraulic load relief system was put back in. It's no big deal technically, but when all the margin in the schedule has been used up it becomes a huge deal politically and contractually.
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Old 10th Jun 2016, 15:41
  #469 (permalink)  
 
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So Boeing thought that a possibly cheaper software solution would work, increasing shareholders returns, sadly the software solution was ever so slightly oversold. End result redesign the area around the boom to accommodate the hydraulic system, lots more work for the production planners etc.

Was the software solution by itself ever tried on the KC-10, as either a proposed improvement to the design or as a test for the KC-46A, as a risk mitigation trial? I think that we know the answer.

Who signed off the design for the boom with just the fly by wire software, was it Boeing or the USAF?
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Old 10th Jun 2016, 16:32
  #470 (permalink)  
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To be fair to ol' Bubba Boeing, if the software geeks told him that their FBW system would be smarter, lighter and simpler than a dedicated hydraulic system, fair enough to go with their design.

Just a pity that they were wrong.

Mind you, I hope that the test programme is a bit smarter than one of the A330 test points. It seems that they wanted to test the emergency boom retraction system, which started as intended. But they forgot to disable the normal boom hydraulics at the time, so the boom reacted to the upward motion of the boom as it normally would, by applying a downward force to keep it where the operator intended. The struggle continued until eventually the retraction cable gave up and went twang. This caused the boom to slam down, break off and disappear into the landscape below....
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Old 10th Jun 2016, 18:47
  #471 (permalink)  
 
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So Boeing thought that a possibly cheaper software solution would work, increasing shareholders returns, sadly the software solution was ever so slightly oversold. End result redesign the area around the boom to accommodate the hydraulic system, lots more work for the production planners etc.
Actually, very little redesign was needed. The boom envelope essentially did not change when the KC-10 boom became the KC-46 boom. The empty space where the old load relief device was located was filled with an updated load relief device and only minimal changes were required to the hydraulic tubing to accommodate the device.

And no, the KC-10 never had a digital FBW system.

Who signed off the design for the boom with just the fly by wire software, was it Boeing or the USAF?
Both. But that's exactly why there's a flight test program, to catch things like this before full production. This is fairly typical. But the change adds to the flight test and certification schedule, and with no margin in that schedule, it causes a slip. USAF will negotiate with Boeing to determine the impact of that slip and the financial penalties, if any.
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Old 11th Jun 2016, 11:34
  #472 (permalink)  
 
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Beags - I don't think it was an emergency retraction system, pretty sure it was an optional backup hoist system. Nothing to do with nozzle/receptacle contact or load alleviation (relief).

Interesting that a small redesign on the KC-46 load relief device has resulted in a 7 month delay.
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Old 11th Jun 2016, 12:22
  #473 (permalink)  
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Apologies for my terminological inexactitude - it was the back up system used to raise the boom assembly flush with the tanker fuselage which was being tested without the primary system having been disabled. Which led to the tug o' war and loss of the boom.
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Old 14th Jul 2016, 09:51
  #474 (permalink)  
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Sources: Reworked KC-46 Boom Refuels F-16, C-17

"FARNBOROUGH, England — The KC-46A Pegasus tanker has successfully refueled an F-16 and C-17, an important step as Boeing attempts to fix an issue with the refueling boom that earlier this year caused a major program delay. Two sources with knowledge of the situation tell Defense News that the reworked boom was able to refuel both aircraft. The US Air Force is expected to announce the news Wednesday afternoon.

It is especially notable that the C-17 was able to be refueled, as the issue with the boom was first discovered when the tanker went to fill the heavier planes in the Air Force fleet. The reworked boom design features a bypass, roughly the size of a paperback book, which helps control the fuel flow while refueling heavier aircraft. Boeing began flying the new boom design at the start of July. One source said the boom should be tested on the A-10 Warthog “soon,” which would represent the final receiving aircraft that needs to be tested to collect enough data for the service to begin a Milestone C decision review."..........
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Old 14th Jul 2016, 15:07
  #475 (permalink)  
 
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If the C-17 gave fits to the first KC-46 Boom, wouldn't it be worse with the C-5? Haven't heard that refueling the C-5 has been tested.
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Old 14th Jul 2016, 15:14
  #476 (permalink)  
 
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KC-46 Successfully Refuels C-17
FARNBOROUGH—A KC-46 equipped with a reworked boom has successfully refueled a C-17 heavy cargo aircraft, a sign that Boeing’s tanker troubles may finally be coming to an end.

“While it took some time, this week’s results confirm my confidence the Boeing team will get this figured out. It’s reassuring to see the program take this important step toward the production decision in August,” U.S. Air Force Chief Gen. Dave Goldfein said in an email statement. The successful C-17 test took place July 12, a few days after the KC-46 with the fixed boom refueled an F-16 on July 8. Boeing’s tanker will attempt to transfer fuel to an A-10 later this month, the final flight test required before a Milestone C decision to formally approve production.

This most recent flight test shows Boeing has fixed the boom instability problem seen during refueling of large aircraft that has plagued the next-generation tanker program for months. “I’m encouraged by these results. The KC-46 program continues to move forward, making important progress that will get this vital capability into the hands of the warfighter,” U.S. Air Force Secretary Deborah James said.
The problem came down to excess pressure on the boom telescope control loop, which controls the extension and retraction of the boom during refueling. The control loop must maintain enough contact pressure to keep the refueling nozzle connected, but not so much pressure as to place excessive force on either the tanker or the receiver aircraft, U.S. Air Force spokesman Daryl Meyer told Aviation Week. The problem was discovered during recent flight tests with the C-17 heavy cargo aircraft.

Boeing’s hardware solution to the problem involves using a hydraulic relief valve on the KC-46 to ensure it will properly alleviate axial loads in flight, Meyer said. The program’s schedule has not changed beyond what Boeing discussed in late May, officials say. Boeing will begin delivering ready-to-go tankers in August 2017 and the last of 18 required aircraft in January 2018—a five-month slip. To accelerate the flight-test program, Boeing recently added a fifth engineering and manufacturing development aircraft to the fleet, Meyer told Aviation Week. Once the hardware fix is verified, a KC-46 with the updated boom will complete regression testing on the F-16, followed by aerial refueling demonstrations with the C-17 and A-10.

The Pentagon is in the process of determining whether Boeing will incur any penalty for the most recent schedule delay.
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Old 14th Jul 2016, 18:03
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Off Topic but ..
Originally Posted by KenV View Post
U.S. Air Force Chief Gen. Dave Goldfein
... holy smokes, it's a small world.
7. June 1995 - May 1996, special assistant to the Commander, Allied Air Forces Southern Europe and 16th Air Force, Naples, Italy
I ran into him, and remember working with him on some NATO stuff. AFSOUTH and IFOR mostly ... 20 years ago. (And in deep memory, I think we recalled being at the same Boy Scout Camp 20+ years before that ...)
I guess he did a whole lot better than I did!
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Old 14th Jul 2016, 20:28
  #478 (permalink)  
 
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I guess he did a whole lot better than I did!
Really? After all, he had to settle for the Air Force!

CG
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Old 14th Jul 2016, 22:16
  #479 (permalink)  
 
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Interesting that after wasting months trying to fix it with software, it turned out to be a (relatively) quick and easy hardware fix. Being all to familiar with the SOP of trying to fix hardware problems with fancy software, this surprises me not at all

Lonewolf, I used to work with a certain young lady when she hired into my group ~30 years ago as a fresh out of college engineer. Today, although not so young any more, she's a Boeing VP and heads up an entire Boeing facility. Recently I was discussing this individual with a female coworker who also worked closely with her back then. When I made a comment along line of how much better this individual had done that we had, my coworker responded that it all depends on what you want - and neither one of us had wanted to deal with the hassle and stress of management. So we all got what we wanted - it just that the individual in question wanted something different.
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Old 15th Jul 2016, 01:11
  #480 (permalink)  
 
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Originally Posted by tdracer View Post
Lonewolf, I used to work with a certain young lady when she hired into my group ~30 years ago as a fresh out of college engineer. Today, although not so young any more, she's a Boeing VP and heads up an entire Boeing facility. Recently I was discussing this individual with a female coworker who also worked closely with her back then. When I made a comment along line of how much better this individual had done that we had, my coworker responded that it all depends on what you want - and neither one of us had wanted to deal with the hassle and stress of management. So we all got what we wanted - it just that the individual in question wanted something different.
td, very kind of you, but there's a difference between choices we make and being chosen from a lot of talent in the pack.

I was not chosen ... I'd say for good enough reasons ... for the flag rank track. He done good at the chosen profession. (As have many others who also didn't get stars ...)

Back on topic, it is nice to see that the occasional hardware fix is still acceptable. There's not always "an app for that!"
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