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Positive aircraft control vs. stabilized or stable flight

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Positive aircraft control vs. stabilized or stable flight

Old 24th Apr 2020, 13:57
  #1 (permalink)  
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Join Date: Mar 2006
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Positive aircraft control vs. stabilized or stable flight

Hi!

I am searching for a term that would describe the ability or inability to maintain flight parameters such as airspeed, direction, altitude, attitude and so on.
When searching "positive aircraft control" most of articles are about always having hands on controls and "stabilized flight" gives approach related articles and "stable flight" goes into stability. In short, I'm not having any success in my searches.

I'm looking for a term to elegantly describe the abort conditions to an approach to OGE hover for winching or abort an approach to an off-airfield landing.
If the community would be so kind to provide me with a correct term or at least point me in a direction to continue my search, I would be forever grateful.

And then I'm going to translate the sh*t out of that term into my native language.

Thank you!
blazkowic is offline  
Old 24th Apr 2020, 14:39
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How about 'sloppy stick?

The Sikorsky S55 and the Westland Whirlwind version did not have any feel or opposition built into cyclic stick. There was a variable friction that one could try but it was unreliable and had a tendency to jam.

That then entailed keeping one's hand on the cyclic continuously. Let it go and the stick fell over and the aircraft followed it. Progressing onto later helicopters with artificial feel and trim requirements took some getting used to.
Fareastdriver is offline  
Old 24th Apr 2020, 14:53
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Possibly adapt something along the lines of satisfactory vs. unsatisfactory performance as defied in the FAA helicopter ATP PTS.
JimEli is offline  
Old 24th Apr 2020, 18:54
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Stable Vs unstable approach with a description of parameters (within X of briefed speed, max ROD, pitch attitude etc.)

LZ
Hot_LZ is offline  
Old 25th Apr 2020, 14:23
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Effective flight parameters control, maybe?

By the way, what's your native language?
Jimmy. is offline  
Old 26th Apr 2020, 10:32
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Controlled Flight would seem one option.

Inability to maintain desired flight parameters could be the condition for the abort.

Inadequate power or references available for the OGE hover.

Undemanded deviation from desired flightpath.

crab@SAAvn.co.uk is offline  
Old 26th Apr 2020, 20:52
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You f**ked it up.
Fareastdriver is offline  
Old 27th Apr 2020, 08:56
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Originally Posted by Fareastdriver View Post
You f**ked it up.
In CFS speak please FED - Bloggs, I took control because you f**ked it up, the reason you f**ked it up is that you are a f**king muppet, next time fly it properly and don't f**k it up again
crab@SAAvn.co.uk is offline  
Old 27th Apr 2020, 09:18
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Thank you all for your responses.

I think I'll stay away from "terminology" and go with something along:"when pilot flying is unable to maintain the desired approach path, he should not slowdown or descend further" and follow up with an explanation what deviating from the desired approach path means .

And for Jimmy. : "Ko leteči pilot ne mora vzdrževati željenega profila prileta naj preneha z upočasnjevanjem in spuščanjem." That is slovenian language for you.

p.s. I'm still trying to get to the bottom of "positive aircraft control" because in my opinion that should stand for when pilot does something the aircraft does it. Or for helicopters: when helicopter does something the pilot is able to stop it. Whereas negative aircraft control would be where pilot is unable to stop the helicopter from doing its own thing...
blazkowic is offline  
Old 27th Apr 2020, 10:24
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Originally Posted by blazkowic View Post
Thank you all for your responses.

I think I'll stay away from "terminology" and go with something along:"when pilot flying is unable to maintain the desired approach path, he should not slowdown or descend further" and follow up with an explanation what deviating from the desired approach path means .

And for Jimmy. : "Ko leteči pilot ne mora vzdrževati željenega profila prileta naj preneha z upočasnjevanjem in spuščanjem." That is slovenian language for you.

p.s. I'm still trying to get to the bottom of "positive aircraft control" because in my opinion that should stand for when pilot does something the aircraft does it. Or for helicopters: when helicopter does something the pilot is able to stop it. Whereas negative aircraft control would be where pilot is unable to stop the helicopter from doing its own thing...
But if the pilot can't stop the helicopter doing its own thing that would be 'loss of control'.

Perhaps positive control is the result of a control or AP input whereas negative control would be an external influence (wind, downdraught etc)
crab@SAAvn.co.uk is offline  
Old 27th Apr 2020, 11:41
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cpt
 
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Hello Blazkowic,

"positive aircraft control" rings me a bell about a system that was installed on S76s when equipped with the phase2 and3 autopilots. It was called the Pitch Bias Actuator (PBA) and it was designed to: "improve the longitudinal stability of the helicopter and give the cyclic a positive control position gradient in pitch"
In short, when you were accelerating, it was supposed to increase the need of forward motion with the cyclic, and also to compensate the natural tendancy of the rotor to tilt fore and back with the variations of power (collective pitch)
In case of system malfunction we could deactivate this system by pulling its circuit breaker.
Personally, I've never noticed much difference with or without this system operating.
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Old 27th Apr 2020, 11:57
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"Positive aircraft control" = the pilot is flying the aircraft

"Negative aircraft control" = the pilot is a passenger and the aircraft is doing something else.
Ascend Charlie is offline  
Old 27th Apr 2020, 12:03
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I like to think of this in terms of a stabilised approach as described in Annex 1 to Commission Regulation (EU) No 965/2012 (the Operations Regulation):

stabilised approach (SAp)’ means an approach that is flown in a controlled and appropriate manner in terms of configuration, energy and control of the flight path from a pre-determined point or altitude/height down to a point 50 ft above the threshold or the point where the flare manoeuvre is initiated if higher;
Mustapha Cuppa is offline  
Old 27th Apr 2020, 14:41
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Originally Posted by cpt View Post
Hello Blazkowic,

"positive aircraft control" rings me a bell about a system that was installed on S76s when equipped with the phase2 and3 autopilots. It was called the Pitch Bias Actuator (PBA) and it was designed to: "improve the longitudinal stability of the helicopter and give the cyclic a positive control position gradient in pitch"
In short, when you were accelerating, it was supposed to increase the need of forward motion with the cyclic, and also to compensate the natural tendancy of the rotor to tilt fore and back with the variations of power (collective pitch)
In case of system malfunction we could deactivate this system by pulling its circuit breaker.
Personally, I've never noticed much difference with or without this system operating.
A PBA was installed on the A model UH-60 also. Strangely, it was conspicuously required to be deactivated and removed from the aircraft during the period the helicopter was grounded for pitch-over accidents. Oddly, the stabilator which was conclusively determined NOT to cause any of the pitch-over accidents, received all the attention and took the blame.

Sorry for the hijack.

Last edited by JimEli; 27th Apr 2020 at 14:54.
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