Pulling the clutch CB on the R44 during preflight ...

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Md500fan
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Pulling the clutch CB on the R44 during preflight ...

Postby Md500fan » Sat Sep 26 2015, 01:04

I was curious as to how all the R44 pilots/owners check the landing light while doing a preflight . My schools current procedure is to pull the clutch circuit breaker and then engage the clutch and then turn on the landing lights to check their operation. Lately I have noticed several clutch engagement issues on startup due to faulty circuit breakers. Of all the Robinson literature I have read I am yet to find a specific procedure. My thoughts have always been that it's bad to continually cycle circuit breakers. Our our aircraft would be flown 5 or 6 times a day so all this adds up. I'm curious as to people's thoughts on weather engaging the clutch is better than pulling the circuit breaker?......
null
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Re: Pulling the clutch CB on the R44 during preflight ...

Postby null » Sat Sep 26 2015, 11:11

Can you not just keep an eye on the ammeter, turn Landing Light on, ammeter drops;Landing light works. No drop, no light.
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Re: Pulling the clutch CB on the R44 during preflight ...

Postby danster313 » Sat Sep 26 2015, 18:09

Hi MD500fan,
im a 44 Driver myself and personally don't worry about checking the landing light, if you need it and turn it on and its not working then fix it, otherwise just take for granted that its working, barely use it anyway. Pulling circuit breakers doesn't really do any damage, I usually have a pull a few here and there to help the starter motor get enough juice, I've been doing it or ages and had no issue.
8)
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Re: Pulling the clutch CB on the R44 during preflight ...

Postby Heli Bloke » Sat Sep 26 2015, 22:25

@md500fan

There are many reasons why you would want a serviceable landing light in the aircraft you fly. For example, CASA recommend use of the landing light whenever you're in the vicinity of a non-controlled aerodrome. May I suggest leave the CB in, engage clutch and turn the light on. Reverse procedure after visually checking light.
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Re: Pulling the clutch CB on the R44 during preflight ...

Postby Pinnacle » Sun Sep 27 2015, 02:36

You check the tension of clutch in a pre flight right?.. Why not just flick the lights on at the same time takes one second.
A pre flight should start inside the machine then working around... lights, radios, headsets, MR, license, insurance etc all are needed for any operation and often overlooked

And to not confirm lights are working I feel that's just dumb. it's all about being seen light yourself up like a Christmas tree, bad weather, smoke, haze, snow the list goes on
They are there for a reason use them
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Re: Pulling the clutch CB on the R44 during preflight ...

Postby Turning base » Sun Sep 27 2015, 10:19

Pinnacle,
Please indicate where in the manual it states that you should engage the clutch during a daily inspection?

Tb
Md500fan
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Re: Pulling the clutch CB on the R44 during preflight ...

Postby Md500fan » Sun Sep 27 2015, 15:58

I have looked on line and over the rotorcraft flight manual extensively and can't find any literature that says the clutch needs to be engaged during preflight. I find the Robinson POH pretty vague at the best of times....
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Re: Pulling the clutch CB on the R44 during preflight ...

Postby Pinnacle » Sun Sep 27 2015, 19:45

Nowhere.

Personal preference, cold mornings I used to engage the clutch to stretch the belts as engine would strain trying to turn over while belts were cold and tight.

Then I had two incidents with clutch not engaging due to a lost electrical contact on the worm drive.. With pax on so not the best look when you need to swap helicopters.

So due to these little lessons I turn it on during my pre flight
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Re: Pulling the clutch CB on the R44 during preflight ...

Postby CYHeli » Sun Sep 27 2015, 23:00

I also teach what was referred to in the original post. The wear and tear on a CB is the least of your problems. The same issue comes up when testing the fuel pumps in a jetty. There are lots of discussions in crew rooms about that one too.
Pulling the CBs allows you to check the landing lights without flattening the battery, which can lead to excessive wear on a starter motor, ring gear, etc which are much bigger issues.

The other point made is about cold mornings. The problem with cold mornings is often related to a cold engine as much as tight belts. I was taught by a number of engineers to let the engine idle for about 30 secs on a cold morning, ALT engaged and once the engine has stabilised (listen for the rpm to stop 'hunting') and then engage the clutch. There is a small risk of the belts rubbing on the lower sheave whilst the engine is warming, but again a cheaper fix than replacing a burnt out starter motor, etc.

The POH is very clear about new belts and leaving the clutch engaged when shutting down, disengage the clutch before the next start.

As has been pointed out, always refer to the manual. The other techniques we all use have been learnt over time and often relate to the cheapest risk.
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Re: Pulling the clutch CB on the R44 during preflight ...

Postby Md500fan » Mon Sep 28 2015, 19:56

So i have spoken to the maintenance department and also spoken directly to Robinson Helicopter. "Your maintenance department is correct: Checking the landing lights using the installed Battery, Clutch, & Landing Light switches (a circuit breaker is not a switch) is the preferred method."
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Re: Pulling the clutch CB on the R44 during preflight ...

Postby Blade Puppeteer » Tue Sep 29 2015, 10:34

I always considered it a good idea to check the Clutch CB during your pre flight.

If the clutch light stays on for more then 10 seconds you are meant to pull the CB

Section 3
Emergency Procedures
Note

Clutch light may come on momentarily during run-up or during flight to retention belts as they warm-up and stretch slightly. This is normal. If, however, the light flickers or comes on in flight and does not go out within 10 seconds, pull CLUTCH circuit breaker and land as soon as practical. Reduce power and land immediately if there are other indication of drive system failure (be prepared to enter autorotation) Inspect drive system for possible malfunction.

So in the cold/hot morning. Engage the Clutch turn on landing light and check landing lights. Then pull clutch CB make sure clutch has been disengaged by circuit breaker then push circuit breaker back in and disengage the clutch via the switch.

Safe Flying

BP
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Re: Pulling the clutch CB on the R44 during preflight ...

Postby bangequalsbad » Tue Sep 29 2015, 12:51

[
Blade Puppeteer wrote:Then pull clutch CB make sure clutch has been disengaged by circuit breaker then push circuit breaker back in and disengage the clutch via the switch.


Wait, hang on, wouldn't pulling the CB prevent the clutch from disengaging MORE? I thought the point of pulling it (the CB) would have been to prevent the clutch from disengaging more resulting in the disconnection of the drive train.
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Ian Batton
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Re: Pulling the clutch CB on the R44 during preflight ...

Postby Ian Batton » Wed Sep 30 2015, 00:33

WOW you guys make things complicated,
1 Turn on the landing light,
2 Turn on the clutch,
3 Turn on the battery run !!!!! if you must,
to the front of the chopper see if lights are working, be prepared to make mental note of what light is not working if one is not working, run back to cabin if you must,
4 turn off master,
5 then turn off landing lights and
6 then turn off clutch, don’t worry about letting the clutch disengage as it will have hardly moved, when you next go to start the chopper and you turn on the master the clutch will complete it disengaging process whilst you are checking gages for correct readings and area clear! this process is for very poor battery performance, if your battery is good then do as per Flight Manual

Or during per flight with old style lights you can almost see if the element is broken just by looking closely at them. I am an old school believer that the more you turn them on and off the faster they break! Right or wrong, it’s my belief.
Now where's my beer
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Blade Puppeteer
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Re: Pulling the clutch CB on the R44 during preflight ...

Postby Blade Puppeteer » Wed Sep 30 2015, 10:38

bangequalsbad wrote:[
Blade Puppeteer wrote:Then pull clutch CB make sure clutch has been disengaged by circuit breaker then push circuit breaker back in and disengage the clutch via the switch.


Wait, hang on, wouldn't pulling the CB prevent the clutch from disengaging MORE? I thought the point of pulling it (the CB) would have been to prevent the clutch from disengaging more resulting in the disconnection of the drive train.



Pulling the circuit breaker disconnects the clutch from the circuit. So by checking the circuit breaker you are making sure you can stop the clutch from disengaging or over "engaging" tightening of the belts.
The 10 second rule applys for either direction (engaging or disengaging)

Ian's method is fine for checking the landing light. But I still think you should be checking the CB to make sure it is actually disconnecting the Clutch from the circuit. I would hate to find out the hard way.

But as has been passed down to me "you'll work it out"

BP
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Re: Pulling the clutch CB on the R44 during preflight ...

Postby actionman » Thu Oct 1 2015, 09:05

I suppose one question is, why Robinson in all their wisdom interlocked the landing light with the clutch switch anyway, I am hoping it is for a reason other than the elite of all Pilots (Helicopter) walking away from the machine with the rotors still turning and the masters and headlight still on and flattening the battery..
Ideas??
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CYHeli
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Re: Pulling the clutch CB on the R44 during preflight ...

Postby CYHeli » Thu Oct 1 2015, 23:08

Reduce battery drain at start up.
The clutch must be disengaged at start up, so by having other systems powered through the clutch switch, it reduces the load on the battery.

Another system that runs through the clutch switch in a Raven II is the AUX fuel pump.
If the Aux fuel pump fails (loss of pressure) the light comes on. So how do you know when the mechanical pump fails? The engine needs at least one pump to operate, so if the Aux (electric) pump is only on when the clutch is engaged, then the engine won't run if the mechanical pump has failed with the clutch disengaged. Either the aircraft won't start or as soon as you disengage the clutch at shut-down, the engine dead stops due lack of fuel.
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Re: Pulling the clutch CB on the R44 during preflight ...

Postby actionman » Fri Oct 2 2015, 02:58

You may need to explain that a little better CY, the way I read that is that I can't use the aux fuel pump as part of the eng prime process in the pre-start. Clutch switch is in the disengaged position during pre-start.
Cheers
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Re: Pulling the clutch CB on the R44 during preflight ...

Postby CYHeli » Fri Oct 2 2015, 03:54

Good point.
To clarify, the ignition switch moved to the prime position overrides and uses a separate circuit to engage the Aux pump and introduce fuel.
Then the switch is returned to both and the engine is started on the mechanical pump only.
Watch (scan) the Aux fuel light during the sequence.
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Re: Pulling the clutch CB on the R44 during preflight ...

Postby Waka topatopa » Fri Oct 2 2015, 04:40

If you feel better knowing the landing light works check it as part of your pre- shutdown procedure?

Likewise with the Clutch circuit breaker, pull it after you close the throttle and disengage the clutch to see if its working.

I've never seen a circuit breaker fail from being pulled, personally I pull the hydraulic circuit breaker after switching the hydraulic switch off after start up to test that circuit is working.

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