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Airbus Helicopters offering X3/Racer to US Army

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Airbus Helicopters offering X3/Racer to US Army

Old 24th Feb 2019, 10:03
  #21 (permalink)  
 
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Heli

Sikorsky leaning auto “correct” coupled with far sightedness.
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Old 24th Feb 2019, 12:40
  #22 (permalink)  
 
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Thanks, BH9-had not heard about Australia actually using the 130 transport kit.

I realized that I didnít finish the raised rotor/performance story. The actual UTTAS forward flight spec data point requirement was: At Design Gross Weight and at 4000í/95F, the cruise speed requirement was 145 KTAS. In order to make that point, we did a long list of aerodynamic cleanup on the fuselage, added rotor diameter thru extended main blade tip caps, and utilized the stabilator to optimize fuselage trim attitude ( in fact that was a secondary but significant factor in the decision to add the FBW stabilator ). Note of interest re the stabilator technology: a few years later, I was at Ft Rucker and had a chance to look at a new production AH-64. Walking around their stabilator I noticed a familiar appearance in the stabilator actuator, and got down to look at the part number. it began with 70-xxxx etc-. UH-60 part numbers all start with 70-xxx etc.
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Old 24th Feb 2019, 14:02
  #23 (permalink)  
 
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Originally Posted by JohnDixson
It began with 70-xxxx etc-.
As you know John, the stabilator was my dad's baby. He never forgave the Army for taking the stabilator and putting it on a competitor's helicopter. That aside it is a validation of the whole scheme.
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Old 24th Feb 2019, 17:39
  #24 (permalink)  
 
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Originally Posted by JimEli View Post
Self-deployment is always an option.
Always? Hardly, that depends on what design choices are made. If AAR kit is folded into the design, then yeah, it begins to become part of the art of the possible.
Historical note: Sherman Tank dimensions were influenced by deployability: they had to fit into certain ships to get across the ocean.
I well recall Blackhawks going up to Newberg to get delivered, (but not by C-130, it was C-5 or C-17 ...)
Comment in re v-280 self deployability: that's been included in some of the Bell literature, but that's (so far as I can tell) salesmanship at this point rather than demonstrated capability.
We'll see how the folks at Bell apply their V-22 lessons learned on that.

I'll need to research that RFP you cited to see what I can squeeze out of it. Get back to you in a few days.
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Old 24th Feb 2019, 18:17
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I was told that the Army was given the dimensions of the C-130 cabin and they passed that on to those who chose to compete on the UTTAS competition. What was not passed on was the fact that most of the Air Forces C-130's had been outfitted with the equipment used for extraction of cargo by parachute. That raised the actual floor enough that no UTTAS aircraft would fit.
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Old 24th Feb 2019, 18:42
  #26 (permalink)  
 
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Originally Posted by Lonewolf_50 View Post
Always? Hardly, that depends on what design choices are made. If AAR kit is folded into the design, then yeah, it begins to become part of the art of the possible.
...
Who said anything about AAR?
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Old 24th Feb 2019, 20:17
  #27 (permalink)  
 
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Indeed, IFMU, your dad made the first flight and the initial envelope expansion tests associated with the stabilator. FBW in 1975. That the stabilator programming came together so quickly is a result of his work. Can’t blame him for being upset to see his work transferred to other OEM’s without so much as a thank you. Wasn’t just the stabilator. The CH-54 load stabilization and precision ( remote controlled ) over system designed and flight tested out of his Engr Branch was similarly passed to Boeing and resided in their HLH proposal.
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Old 24th Feb 2019, 23:22
  #28 (permalink)  
 
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Also the blade balancing system.
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Old 25th Feb 2019, 07:08
  #29 (permalink)  
 
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Originally Posted by Al M View Post
Also the blade balancing system.
You mean the large area washers added when doing main rotor balancing with the Chadwick-Helmuth kit? That was always fun. Read the phase angle and IPS on the box, then refer to the chart in the manual to see how many washers to add to which location(s). It worked fine on our 1981 UH-60As. Just make sure you have the cable that connects the accelerometer up top to the test box in the cabin firmly secured, as any slack will sound just like you're taking small-arms hits and may skew the vib readings. Ah, good times!

On the subject of air transportability:

In around 1987, our Germany-based US Army combat aviation unit was instructed to prepare 2 of our Blackhawks for air transportability as part of a training exercise. One was to be loaded on a C-5 and one on the C-141. We actually sent one of our birds over to Rhein-Main or Ramstein (can't remember which) to visit with a C-5 crew and see how well the loading and unloading went. The guys who went along to do the prep work didn't break anything so I guess it went okay. I remember from school that you had to use a hydraulic mule to extend and retract the shock struts to avoid scraping the belly during ramp loading. Thankfully we never actually had to demonstrate it on the C-141. To fit in the 141, the rotor head had to be partially disassembled and lowered. Lots of work, especially putting it all back together with the brass split rings and pressure plate torquing. I was assigned to the crew that got to do all that in the comfort of our own hangar. And the post-mx test flight as well. If you fixed it, you flew with it! Tech inspectors too.

Last edited by westhawk; 25th Feb 2019 at 07:18.
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Old 25th Feb 2019, 16:01
  #30 (permalink)  
 
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Originally Posted by JimEli View Post
Who said anything about AAR?
The US military has to deploy to do most of what it does. That is why I raised that point in response to this thread's OP.
Function.
Given the various responses to my post, to include yours, some of which pointed to "self deployability" as an answer, AAR, like the V-22 has, is a way to get around the problem of "does it fit into air transport to get sent to yet another godforsaken corner of the globe"

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Old 26th Feb 2019, 13:19
  #31 (permalink)  
 
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Westhawk.

No. I am talking about the blade balancing used at the factory on a whirl test stand using (at one time) the Chicago Aerial tracker prior to the blades being installed on an aircraft or delivered as a spare or an overhaul. This balancing includes adjusting the bade pitching moment(push rod load), track, and obtaining the pretrack number so the aircraft rotating push rods can be set to the correct length..

Last edited by Al M; 26th Feb 2019 at 16:54. Reason: add info
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