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More KC-46A woes....

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More KC-46A woes....

Old 9th Jun 2021, 20:39
  #1121 (permalink)  
 
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Originally Posted by gums View Post
Salute!

I thot the beast already had drogue feeds like the KC-10, besides with a short drogue on the boom it only allows one refueling op at a time.
Gotta check the spec again..... BRB.

Gums sends...
Gums, the USAF requirement was that the KC-46 could refuel 3 aircraft simultaneously - I've not heard anything to the effect that they are not meeting that requirement.
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Old 9th Jun 2021, 21:54
  #1122 (permalink)  
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Gums, the USAF requirement was that the KC-46 could refuel 3 aircraft simultaneously - I've not heard anything to the effect that they are not meeting that requirement.
Three abreast? That would be an achievement with that wingspan. The VC-10 norm was either one centreline or two on the wing hoses.

I believe, theoretically, all three at once was possible but clearance was marginal if a break- away was required.

Best of luck with the trials - I await the videos with anticipation…
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Old 9th Jun 2021, 22:11
  #1123 (permalink)  
 
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Salute!

Agree with TD, and I think we can find a pic of three receivers hooked up at one time.

My basic feeling is the probe is for special ops helos and the Osprey and the F-35 Bees some folks want and/or need.

I will guarantee that in a high intensity scenario you can get more gas passed faster to more planes than you can with the probe. I watched the scenario during LB 2 and was amazed. I also escorted a burning Jolly outta North Vee and he was able to hit the drogue and then limp in to NKP.

I only used the probe twice when flying the A-37B and it depended a lot more on me than the tanker. I liked the receptacle combo more due to getting the best outta me and the boom op. The receptacle also transferred more fuel per minute.

Gums sends..

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Old 10th Jun 2021, 14:46
  #1124 (permalink)  
 
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So with a requirement to refuel 3 ac at once, was the USAF going to rewrite the appropriate safety procedures for ATP56; that would probably take longer than sorting out the KC46.

To be fair at least the KC46 would in theory at least be able to refuel all NATO receivers, big, small and probe.
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Old 10th Jun 2021, 16:15
  #1125 (permalink)  
 
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Salute!

Looks to me, Vasco, that the pods on the wings are for the probe receivers and main boom is the only one for receptacle dudes.

The probe folks like the F-35's and Hornets and some RAF/RN can easily hook up two at a time, way it looks.

Other things bother me, but not the receptacle or probe aspects of the plane. Of course, the stoopid remote TV for the boom op is my biggest gripe.

Gums sends..




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Old 10th Jun 2021, 16:55
  #1126 (permalink)  
 
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Gums

The ac has wing pods, centre line drogue and boom. So in theory you could have say 3 FJs connected at the same time . The problem is that the safety procedures as written don't give the 3 rd receiver anywhere to go if vis contact is lost when astern. Whether the ac systems would allow for such AAR -I have no idea.

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Old 10th Jun 2021, 17:56
  #1127 (permalink)  
 
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Salute!
Good point, Vasco. May have to look up latest guidance.

My recollection was to hit the disconnect button, reduce power, drop low and back off. No movement left or right until altitude separation. The procedure was a bear at night in weather, but somehow thousands of us made it.

The 'nam gaggles usually had four lights close, And maybe another four-ship sitting alongside and high, waiting their turn. About an hour before first bombs dropped. We were talking about two hundred plane raids with maybe 4 or 5 tankers over Laos and another two tankers for the Navy dudes out over the S. China Sea.

The receptacle drill was usually like clockwork and my flight topped off in about 7 or 8 minutes, max.

Without the need for the boom, I feel the RN Bees have it made and can refuel two at a time on the '46".

Gums sends...





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Old 10th Jun 2021, 18:39
  #1128 (permalink)  
 
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Hi Gums

The issue is with 3 rx on hoses at once. RH guy goes down 1000 if still lost contact the one on the left goes 500, so where does the one in the middle go? The ATP says 500 down which is occupied, hence the need for a rethink. Admittedly not a likely scenario combination but one that would need legislating for.
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Old 10th Jun 2021, 21:24
  #1129 (permalink)  
 
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Vasco ,A-A Tacan offset with height/range..?
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Old 10th Jun 2021, 22:19
  #1130 (permalink)  
 
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Salute!

I only had to do the four ship weather break out, so we went left/right/down and lead kept going st a head, slight descent.

I would not award a major contract to the users if they did not have their sierra together. Good grief.

I ask all of you how many times you hooked up at night during a rain storm, not a thunderstorm ith lightning and such.

You design and train for the weakest link, but define that condition and pilot capability., Right?

I like the receptacle refueling ( heh heh it's easier!), but I unnerstan the probe requirement for some of the planes due to mission and other requirements.

Gums sends...
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Old 11th Jun 2021, 05:52
  #1131 (permalink)  
 
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Gums and Sycamore

At the risk of repeating the point, the specific (admittedly very rare) event that I am alluding to is that of the rxs losing visual on disconnection (either on breakaway or routine) and all 3 now astern (not on the wing) and unable to see the tanker or each other. Any offset etc is after the initial action which requires immediate sanctuary heights. The bottom line is that the guy in the middle has nowhere to go. It is obviously considered an issue because there is a specific procedure in ATP 56 (or whatever it is called these days). It is that rare point that currently precludes having 3 rx in contact .
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Old 11th Jun 2021, 13:09
  #1132 (permalink)  
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Controlling the simultaneous safe movement of 3 receivers onto the hoses, making contact, refuelling, disconnecting and moving to echelon would be fraught with risk. 2 receivers can take immediate action if one threatens the other with inappropriate manoeuvring, but 3? Recipe for disaster. Also the air refuelling operator would have to monitor position, hose state, offload rate and fuel transferred - far too easy to make the wrong call to the wrong receiver.

2 receivers are fine, although I did once have to disabuse a clever bugger test pilot who thought that there was nothing wrong with clearing 2 receivers to make contact simultaneously.

AAR procedures have been developed to a consistent safe standard over the years. Reinventing the wheel is unnecessary!

That said, the US Navy did once refuel 4 x F9F Cougars simultaneously from a Convair R3Y Tradewind.



The Cougar had a wingspan only 6" shorter than an F-35B and although the Tradewind had a wingspan 10' shorter than the KC-46A, the outboard pods are about the same distance out from the aircraft centrelin. The event looks to have been rather....sporty.
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Old 17th Jun 2021, 07:45
  #1133 (permalink)  
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Yet more woes................
During a June 16 hearing, multiple members of the House Armed Services Committee said the Air Force should consider re-competing the KC-46 program because of extensive delays and performance issues with the Boeing aircraft.

Rep. Rob Wittman (R-Va.) accused the Air Force of paying $226 million for a “lemon.” He said “it is time that something changes.”

Acting Air Force Secretary John P. Roth defended the program and said re-competing the tanker program makes no “economic or business sense.” The best way forward, he said, is to work within current contracts to improve the aircraft to make it “hopefully ready” by 2023 or 2024.
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Old 17th Jun 2021, 12:04
  #1134 (permalink)  
 
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"hopefully".................. oh dear......................
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Old 17th Jun 2021, 12:07
  #1135 (permalink)  
 
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Old Chinese proverb. 'It is better to travel hopefully than to arrive'.
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Old 17th Jun 2021, 15:50
  #1136 (permalink)  
 
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Originally Posted by ancientaviator62 View Post
Old Chinese proverb. 'It is better to travel hopefully than to arrive'.
I suppose the OEM buys into that proverb. The USAF should stipulate that they get only paid for arriving not hoping.
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Old 18th Jun 2021, 07:31
  #1137 (permalink)  
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Stability issues?……

https://www.defensenews.com/air/2021...-deficiencies/

More cost overruns are coming for Boeing as the KC-46 program logs another two technical deficiencies

WASHINGTON — Boeing will have to pay to fix two new technical problems afflicting the KC-46 refueling tanker, which the U.S. Air Force has designated as “category 1” deficiencies that rank among the program’s most critical issues.

The Air Force has discovered that drain tubes in the KC-46′s air refueling receptacle — which are used to remove water from the aircraft — can become cracked when the tanker operates in cold temperatures, the service stated in response to questions from Defense News. According to the service, this issue has occurred approximately three times, when water in the tubes froze and expanded, forming cracks.

The second problem involves a software bug in the KC-46′s Flight Management System, which has triggered “navigation anomalies,” according to Boeing.

The Air Force said this issue has been limited to “isolated incidents,” most recently during a March 3 flight over the Pacific Ocean. Then, the crew “deferred to other navigation methods and did not declare an in-flight emergency” before landing safely in Honolulu, the service said.

Boeing added that the problem did not make the aircraft less safe and that each KC-46 has since been cleared for flight.…..

As a short term strategy for dealing with the cracked aerial refueling receptacle tube issue, Boeing has issued inspection guidance to the Air Force to mitigate known risk factors. To permanently fix the problem, however, it will have to redesign the drain line tubes and retrofit existing KC-46s with the modification, the service said.

General Electric — Boeing’s subcontractor for the Flight Management System — is already testing a software fix aimed at resolving stability problems.

To mitigate current risks, Boeing has issued guidance to help KC-46 crews to reset the system if a problem is experienced during flight. It has also delivered updated pre-flight procedures aimed at decreasing the likelihood of a software anomaly, the Air Force said.

The Air Force classified the two new problems as “category 1” deficiencies in May 2021.

Four other CAT-1 problems remain on the books: two issues with the Remote Vision System —the camera and sensor suite that provides imagery of the receiver aircraft to boom operators during a refueling — which requires Boeing to redesign the system; a problem with the stiffness of the boom that prevents some aircraft from being able to receive fuel; and an issue with fuel leaks.……

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Old 14th Jul 2021, 08:32
  #1138 (permalink)  
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Use of centreline Drogue finally approved….

https://www.18af.amc.af.mil/News/Art...rst-kc-46a-in/

AMC approves operational use of the Centerline Drogue System as first KC-46A Interim Capability Release milestone
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Old 14th Jul 2021, 10:20
  #1139 (permalink)  
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Those photos show the F-18 sitting too low on the hose, which should have a slight bend to avoid stress on the probe tip.

Last edited by BEagle; 10th Aug 2021 at 19:36.
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Old 14th Jul 2021, 12:19
  #1140 (permalink)  
 
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Originally Posted by ORAC View Post
Use of centreline Drogue finally approved….

https://www.18af.amc.af.mil/News/Art...rst-kc-46a-in/

AMC approves operational use of the Centerline Drogue System as first KC-46A Interim Capability Release milestone
While I understand the boom will require MUCH more work with the vision system, why did the centerline drogue take so long? Sorry if I missed that. Are there problems with the the wing pods?
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