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-   -   lets have a sit down, shall we?? (https://www.pprune.org/rotorheads/543165-lets-have-sit-down-shall-we.html)

Fun Police 8th Jul 2014 01:14

lets have a sit down, shall we??
 
so recently, i observed a collegue sitting on top of the rotorhead of an AS350. i thought that it was an odd, even an uncomfortable spot to sit...
personal opinions aside; from an engineering point of view, would this be harmful to the mast bearing/rotor system? i might be just a pilot but i thought that the design was meant more to suspend weight rather than support (extra) weight.
any thoughts? i'd like to know as eventually i will have to fly that aircraft.
TIA
fp

Falcon Al 8th Jul 2014 07:06

If you consider the existing weight of the mast and blades on the lower components then I dont think there is an issue.
How much load/shock would there be in a bouncy landing?

unstable load 8th Jul 2014 07:31

Aside from the risk of falling off and denting the bodywork on the way down, I'd say there's no problem with it. If you consider the loads the mast and transmission absorb in a turn or flare then the weight of a guy sat on the head becomes low.
I'd be worried if he was sitting on the blades outboard of the spindles.

Fun Police 8th Jul 2014 10:59

thanks guys,
i am sure the designers accounted for the weight of the rotor system pressing down statically (and even low negative G's) but to have that extra weight up there...?
also, in a turn or flare wouldn't the loads increase in the direction of the blades rather than the skids?
and yes, damage to the cowls etc had occurred to me as did falling off, but in those cases the individual would likely have to fess up if either damage occurred or he hurt himself.
fp

IFMU 8th Jul 2014 11:58

I don't know how you could make a shaft and head so strong as to be able to pull G in one direction yet be damaged by somebody sitting in it putting some additional weight in the other direction. The bearings won't care. Sure the shaft is loaded in compression rather than tension but how do those loads compare to the shaft under bending when cyclic is applied? They are minuscule. There are better things to worry about.
Bryan

Devil 49 8th Jul 2014 12:21

Sit on the head itself? No problem.
 
Sitting on the assembly covering the head, centering springs and dampening weight itself, is another question. Unless all the weight is born by the lifting eye...

John R81 8th Jul 2014 12:44

why, oh why, did you not press "Crank"???

Vertical Freedom 8th Jul 2014 13:36

Fun police????? More like 'worry about nothin police' :{ or 'nonsense police' or 'boredem police' :ooh: maybe you just need to get out more & enjoy life :*

311kph 8th Jul 2014 14:47

If it looks cool, why not!?!:ok:
But only if it looks cool!:=

heli1 8th Jul 2014 15:19

Of course when they bring in new rules governing the limits on size for offshore passengers to fit through a window, atop the rotorhead might be the only option for some

Thracian 8th Jul 2014 15:58


Of course when they bring in new rules governing the limits on size for offshore passengers to fit through a window, atop the rotorhead might be the only option for some
But then, as my kung fu master says: Stay centered...:E

Sitting on a rotorhead is a very lonesome place to be.
No room for small talk with other pilots (sitting on other rotorheads of other machines dozens of meters away).
No room for the lunch box.

But still: Great views from there...

at least until John R81 lights the fire:E

John R81 8th Jul 2014 17:39

"Come on baby, light my fire...."

[Add your own music - work with me! Work with me! ] :}:}:}

Actually, "Crank" will spool the motor but not provide fuel so it won't light. Three things will happen:

1. The motor will spool a little and sound like a start;
2. The rotors will move a little, giving Chappie a fright; and
3. A small amount of poo will escape the confines of Chappie's internals

[The fourth thing will be major damage to the blades and to Chappie as he falls off, but difficult to see the humour in that part so I ignored it]

Matari 9th Jul 2014 00:22

What's the big deal?

http://www.aviastar.org/foto/hiller_x-2-235.jpg

47guy's 9th Jul 2014 01:06

Come on!

How do you think we change blow turbine engine in the wild when no crane A frame or chainblock to roof are disponible...

very easy on a 206

Think about it!

Guy

Fun Police 9th Jul 2014 02:30

i will have to think about it as i don't know what a blow turbine is and i consider myself fortunate to not have to know anything about the 206.

fp

47guy's 9th Jul 2014 04:22

1)Simply put a short sling around one of the blade!
(aprox 2.5ft from the blade bolt)
2)hook a chainbock to the sling (small 1/2t is more than anough)
3)hook the chainside hook to the eyeloop bolt of the engine
4)run the chainblock until maximum up
5)then have someone pull gently the other blade down (SEESAW)this will lift the engine out of frame mount
6)turn the rotor to clear the engine compartement
7)run down the chainblock until the engine can reach the work stand

this description is highly simplistic!

So do not worries about weight (the 206 head+blade weight almost 350lb)

Simply think that all mecanical gizmo upthere can sustand the weight of the machine+++add the G' so you are talking probably about TOn's of traction on the head!

I have a photo some were if i ca find it i will paste it hire!

Guy
Sorry english is not my first language!

p.s.
the 206 is one of safest flying machine in the world i do not understand why you seem to be worried about it!(((i consider myself fortunate to not have to know anything about the 206.)))
Surely not the best confortable but it is the CHEVY of the helicopter!

Fun Police 9th Jul 2014 10:55

thanks 47guy, for the explanation, however the original question related to an AS350 which i think we can all agree is a different animal.

fp

311kph 9th Jul 2014 11:49


Surely not the best confortable but it is the CHEVY of the helicopter!
Or as they say in Europe, it is the CITROEN 2CV of the helicopters! :D

Self loading bear 9th Jul 2014 20:10

Firestarter
 
John R81,

Add your own music:

Prodigy Firestarter


When you consider this thread drift, then see this as a small counter balance to the current content of the thread "It's time to show your age, Rotorheads" ;)

SLB

John R81 9th Jul 2014 21:01

:D:D:D:D

I love a bit of thread drift in the evenings

krypton_john 9th Jul 2014 22:24

... prefer the smell of Jet A1 in the morning though...

An_engineer 10th Jul 2014 00:06

Fun Police,

Ever watched engineers putting the blades on a 350? Imagine the loading through the rotor head after the first blade is installed. No problems at all.

If your question is regarding the load through the blade itself, then watch the distance they droop when ground handling across bumpy ground compared to the distance when a carefully placed bum is only a few inches from the mast.

Most aircraft will handle it just fine. Not much to worry about unless someone falls off.

Fun Police 10th Jul 2014 00:19

thank you for a reasonable response to an honest question (not that there were not others... but some... :}).

fp

lelebebbel 10th Jul 2014 07:18


1)Simply put a short sling around one of the blade!
(aprox 2.5ft from the blade bolt)
2)hook a chainbock to the sling (small 1/2t is more than anough)
3)hook the chainside hook to the eyeloop bolt of the engine
4)run the chainblock until maximum up
5)then have someone pull gently the other blade down (SEESAW)this will lift the engine out of frame mount
6)turn the rotor to clear the engine compartement
7)run down the chainblock until the engine can reach the work stand

this description is highly simplistic!

Here is a video of this procedure (timelapse)



Go to 5:30 for the engine lift

311kph 10th Jul 2014 10:19

damn!!! timelaps trough seasons... they started in late summer, and finished in early spring...
great work nonetheless

Guilders 10th Jul 2014 14:11

Fun police, all joking aside, your are probably well advised to never, ever fly that machine.....the integrity of the rotor head has been compromised and will no doubt eventually fly off the helicopter! The phenomena is referred to as LEIRSO* and is a pretty well known cause of failures in some helicopter types; particularly the Eurocopter A Star models!




:ok:
*Lazy Engineer Induced Rotor System Overloading

vfr440 10th Jul 2014 14:50

206 engine removal
 
Sorry, don't think you've got that right, at least as far as the 206 is concerned. I totally agree with 47guys & lelebebbebel; if you are in the bush then you have to use calculated SAFE (including OHS) methods to get the duff donk out, and the new donk in. The strap/chainblock system which is located close to the root of the blade and actually bears upon the reinforced (doublers) is the only way to achieve that result. The naked engine weighs in at around 100+lbs. Allowing for 2 of us experienced LAE's you would probably get a hernia trying to lift at a lever arm of a couple of feet, and if/when you dropped it what collateral damage to the engine and the airframe would be sustained, in all probability rendering any further flight thoroughly unsafe?


Sorry, think you have got that ALL WRONG - VFR


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