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Choppers Rescue Line Pendulum

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Old 10th Jul 2009, 16:31
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Choppers Rescue Line Pendulum

I'm not a pilot, but do work in, (SAR), technical concepts, . .
I'd like to know if a technology has been introduced to stabilize the,
"pendulum effect" occurence that leaves the rescue line swinging out of control ?
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Old 10th Jul 2009, 20:17
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Dont know of SAR Heli's - but if a Chinook (C/D model) had a load resonance issue then it used to be recommended that the driver/jockey was to let go of the cyclic controls and let the Auto Stabs take over.
That eliminated human influences (trembles?) getting into the flt control system and was supposed to settle the resonance within 1.5 to two 30-to-45-degree swings.
That was for the three load hooks mounted in the Centreline of the beast directly influencing attitude(s) somewhat. Don't know if this would work on an external Rescue Hoist.
I remember seeing a Chinook Load Test film of such an event but can't remember if it was a Boeing or a UK JATE film.

Rigga
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Old 10th Jul 2009, 22:05
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I'd like to know if a technology has been introduced to stabilize the,
"pendulum effect" occurence that leaves the rescue line swinging out of control ?
I have been winched into a dozen or so Sea Kings (and one Wessex??? it was many years ago!!) and watched dozens more from the wheel of a lifeboat sometimes stationary and sometimes doing up to 30 knots and have never witnessed a 'pendulum effect' on an empty or loaded rescue line - maybe just lucky!
More probably I just saw well trained SAR crews at work.
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Old 12th Jul 2009, 16:26
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Line Control

Rigga,
I will need to, define, glean, sift, information, as I am pretty much,
"rough conception and modify & Innovation", type developer, but
appreciate
your input.Thank you.

draughtsman99
There are several examples of this occurrence, and one of these has
been documented, and is in the possession of, KVBC TV3, Las Vegas,
Nevada. I believe there are at least two other different recordings,
(different TV stations),
I would like to get my hands on anyone of them,
I intend on submitting a proposal for R&D.Really want one,
but can not afford.Not to worry, I'll get one.
The. "Pendulum Effect" in my view is quite hazardous, and seems to
occur from, "indirect retrieval", water movement, wind, etc.
The thing is in close quarters, cliffs, overhangs, electric power
lines, buildings, etc. there for certain can be problems.
Indirect Retrieval

Pendulum-1
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Old 14th Jul 2009, 14:19
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Pendulum

I think I have a way to solve this pendulum, . . and want to find an engineer who is interested in evaluating a technical concept, for the reason of creating a proposal for R&D.

I am tapped out ! so this would be the only alternative,that I can see.

The thing is to find a way into this category of technical procurement.

If you are an engineer and have experience in developing technology and procuring R&D support, I would like to talk turkey.

The development of equipment to produce compensation and to stabilize this effect, can be the subject of the development of a equipment and instrumentation.

I foresee this as a manual and pilot assist instrument control technology.
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Old 16th Aug 2009, 11:26
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Rescue Line "Pendulum" Effect

I have touched down with the;
United States Special Operations Command
and have sent query regarding the, "Pendulum", Effect.

Also have feelers out in the directory of the, U.S. Army,
PROGRAM EXECUTIVE OFFICE FOR ROTARY WING
and will direct query there.

A Communication From a Chopper Pilot on the subject;

REPLY;

Whenever a helicopter pilot has an external load that starts to swing
(Human or non-human cargo), he will begin to slowly turn and the swinging will cease.

Initiating a shallow turn will remedy the pendulum effect by decreasing
the ability for the load to swing by using centrifigul force. Even at a
slow forward speed with a shallow turn to one direction, it will create a
G Force on the weight, increasing the relative weight on the end of the rope and diminishing the swing.

Simple problem, simple fix.

Glenn
***************************************
REPLY;
Thanks Glenn,

If you say so, however it looked pretty hectic in the flash flood
conditions in the scenario viewed in the Nevada incident I watched on TV some time ago. I'm not sure that pilots always have the time and room, for example, cliffs,bridges, high tension wires, etc.
I will make a note of G forces technique for further technical reference.

***********************************
REPLY

There are exceptions to everything. At a hover, in a confined space, you
do not have many options. That is just the way of things. Sometimes, no
matter what you try to do, it is just not your day.

Glenn

********************************
The thing is the space and time that a pilot has to make a correction to stabilize the swing situation, as stated above with real danger lurking in close quarters there will be times that the margin will be slim.

Giving a pilot all the technical applications to solve his problem may take years of development, but the mile is accomplished by taking the first step.

When seeing this on the documentary videos via the TV, I can see that this a solution is necessary to provide a more precise control in the situation.


If and when I find a slot for an R&D Proposal submission,
I will be looking to acquire some partnership key assets, for participation.
Please let me know if you are interested, I'll keep your contact information on hand as I organize this.

Last edited by Jove; 16th Aug 2009 at 11:29. Reason: Sentence word structure
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