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Santa Barbara Skycrane crash

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Santa Barbara Skycrane crash

Old 9th Nov 2007, 02:54
  #21 (permalink)  
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and separation of the servo unit will result in loss of main rotor blade pitch control.
...masterful understatement from the FAA.
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Old 23rd May 2010, 14:54
  #22 (permalink)  
 
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SkyCrane rear flight controls

"the rear seat is seldom, if ever used"
Does anyone have a picture or video of a SkyCrane rear flight controls installed or better yet, actually being used.
Thanks. Mike, fly911.

.
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Old 23rd May 2010, 22:36
  #23 (permalink)  
 
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S64 rear seat

The rear seat is used predominently for precision placement of loads and does a remarkable job (driven by very experienced pilots) considered the cyclic is very early fly by wire, the collective is mechanical
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Old 23rd May 2010, 23:01
  #24 (permalink)  
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Couple of vids for you showing rear seat operation.

Skip forward to 3:45 on this clip.


Skip to 3:54
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Old 23rd May 2010, 23:11
  #25 (permalink)  
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At the risk of it appearing that I know somethihg about Skycranes, which I really do not.... It does appear to me that the photos of the poor machine lying upside down, show a tail rotor with very little damage. It certainly does not apear that it was turning when it hit the ground. Would stopping the main rotor as happened, also stop that tail rotor that quickly? Or could some other failure have caused it's stopping before the rollover was finished? Either way, it happened quickly!
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Old 24th May 2010, 04:34
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Kenny is here with me in Michigan right now----will ask him in the morning....
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Old 24th May 2010, 08:51
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Cool

Couple of a silly questions but when the rear seat is used does the rear seater have full control and are the cyclic controls reversed?
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Old 24th May 2010, 10:55
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The cyclic works in the correct sense - when you move the cyclic towards the front of the helicopter, the helicopter moves forward.
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Old 24th May 2010, 16:10
  #29 (permalink)  
 
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S-64 Rear Seat Controls

Shawn has the control orthogonality correct. As to the question about "full authority": the rear cyclic acts thru the AFCS for pitch, roll and yaw. It has +/- 10 % authority, and that authority is shown on a cross pointer indicator. The 10 % control range can be shifted by utilizing the rear cyclic beeper trim, and the pilot can see where he is on the cross pointer indicator. "Back in the day" they'd make you fly around the pattern backwards from the rear seat before they'd sign you off.

Thanks,
John Dixson
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Old 24th May 2010, 20:06
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another silly question

Glad no one was hurt
Does the rear facing seat have yaw pedals? cant really see in the clip above. if they are there it appears the pilot is sitting over them rather than having them in front
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Old 24th May 2010, 21:28
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Originally Posted by JohnDixson
"Back in the day" they'd make you fly around the pattern backwards from the rear seat before they'd sign you off.
One can just imagine the confusion this must cause to unsuspecting bystanders...

The C150 in the circuit being overtaken by a 64 reversing around the pattern...
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Old 24th May 2010, 22:11
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Rear Seat Directional Control

Tony 1969, as I wrote, the rear cyclic has yaw control integrated. One twists the control and voila-the big ship turns. Before someone raises the obvious: yes, the major challenge is to make clean, single axis inputs.

Thanks,
John Dixson
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Old 24th May 2010, 23:09
  #33 (permalink)  
 
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John,

If I remember correctly the S64E did not have the yaw function on the back seat controls but the S64F did. I remember riding left seat while setting a radio antenna and the back seat pilot had to ask for yaw adjustments from the pilot flying the right seat. I could be remembering it incorrectly or it may have been something operator specific. I would swear there was some differences though between the E and F model cranes in regards to the back seat controls.

Max
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Old 25th May 2010, 02:24
  #34 (permalink)  
 
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Loss of a wonderful cab.
I have always been impressed by the Skycrane since I had the chance to examine one close up when I was a young man.

john
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Old 25th May 2010, 11:45
  #35 (permalink)  
 
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In sideslip does the system correct for the tail rotor yaw stability or is this just something you get used to?

Thanks.
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Old 25th May 2010, 18:43
  #36 (permalink)  
 
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S-64 Rear Seat

Maxtorq,

CH-54A/S-64E had a modified S-61 type AFCS, Rear seat accomplished yaw control thru the twisting of the cyclic, but required manual beeping to extend the pitch/roll axis authority range. CH-54B/S-64F had the RH-53D type AFCS. Yaw control was still done thru twisting the cyclic, but the pitch/roll authority range extension was different. My memory is hazy on this part, but I think the range was extended thru a trim reshift if you either got to some threshold of the existing authority or touched the electronic cyclic stops. Think it was the former. Maybe some old Crane pilot can help here. In any case, yaw was available on both, and thru twisting the cyclic. People will notice that on the newer SA fly-by-wire controls now in flight test, the yaw controls utilize electric pedals, making pure single axis yaw inputs a lot easier.

Thanks,
John Dixson
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Old 25th May 2010, 18:46
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"Tail Rotor Yaw Stability"??

Not sure what you refer to, Graviman. Both models had heading hold in the AFCS.

Thanks,
John Dixson
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Old 25th May 2010, 20:23
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Thanks for the answer John it was in your original post.
I should just learn to read better
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Old 25th May 2010, 20:56
  #39 (permalink)  
 
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Erickson S64 machines do not have the yaw capability on the cyclic. Yaw control is accomplished by communication with the front seat pilot on the pedals.
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Old 25th May 2010, 21:12
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Ah! see I'm not losing my marbles after all lol

Thanks PT6er
Max
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