View Full Version : Clutch switch position
Stuart & Kathryn Fields
June 26th 07, 04:54 PM
A recent incident involving a Rotorway helicopter occurred.  An accidental 
bumping of the clutch switch dis-engaged the clutch.  The resulting 
autorotation resulted in a roll over and of course some significant damage. 
As I understand it, the switch was mounted in the overhead panel but the 
pilot's headset could make contact and inadvertently cause the clutch 
dis-engagement.  I wonder if the standard switch cover that you have to lift 
to get access to the switch itself would have stopped this occurrence?
-- 
Stuart & Kathryn Fields, Publishers
Experimental Helo magazine
P. O. Box 1585
Inyokern, CA 93527
(760) 377-4478 ph
(760) 408-9747 publication cell
(760) 608-1299 technical cell
www.experimentalhelo.com
www.vkss.com
Steve R
June 26th 07, 06:40 PM
"Stuart & Kathryn Fields" > wrote in message 
.. .
>A recent incident involving a Rotorway helicopter occurred.  An accidental 
>bumping of the clutch switch dis-engaged the clutch.  The resulting 
>autorotation resulted in a roll over and of course some significant damage. 
>As I understand it, the switch was mounted in the overhead panel but the 
>pilot's headset could make contact and inadvertently cause the clutch 
>dis-engagement.  I wonder if the standard switch cover that you have to 
>lift to get access to the switch itself would have stopped this occurrence?
>
> -- 
> Stuart & Kathryn Fields, Publishers
Sounds like a reasonable assumption to me.  It also sounds like having a 
protected switch should be a recommended safety item for any critical 
function, whether or not the switch is in a position to be accidentally 
bumped.
Going slightly off topic, and I'm not meaning to put anyone down here, but 
why is it that just about every emergency autorotation I hear about results 
in significant damage to the helicopter?  Most folks walk away from them, 
which is good, but some don't.  This seems to be fairly common even among 
aircraft that have the reputation of being relatively forgiving in this 
mode.  Are autorotations "that" critical or are the successful ones simply 
not considered to be worthy of news so I'm not hearing/reading about them?
Fly Safe,
Steve R.
Maxwell
June 26th 07, 06:54 PM
"Stuart & Kathryn Fields" > wrote in message 
.. .
>A recent incident involving a Rotorway helicopter occurred.  An accidental 
>bumping of the clutch switch dis-engaged the clutch.  The resulting 
>autorotation resulted in a roll over and of course some significant damage. 
>As I understand it, the switch was mounted in the overhead panel but the 
>pilot's headset could make contact and inadvertently cause the clutch 
>dis-engagement.  I wonder if the standard switch cover that you have to 
>lift to get access to the switch itself would have stopped this occurrence?
>
Would a switch cover not delay ready access to the switch? Sounds like it 
needs to be relocated for safety, and kept quick to select.
Hawkdoc
June 26th 07, 07:27 PM
Instead of a covered switch, use a swich with raised side gaurds to protect 
it. Can't think of any swiches used in most emergency procedures that are 
covered.
James
Rule 6 - "Priorities are man made, not god made"
"Maxwell" > wrote in message 
...
>
> "Stuart & Kathryn Fields" > wrote in message 
> .. .
>>A recent incident involving a Rotorway helicopter occurred.  An accidental 
>>bumping of the clutch switch dis-engaged the clutch.  The resulting 
>>autorotation resulted in a roll over and of course some significant 
>>damage. As I understand it, the switch was mounted in the overhead panel 
>>but the pilot's headset could make contact and inadvertently cause the 
>>clutch dis-engagement.  I wonder if the standard switch cover that you 
>>have to lift to get access to the switch itself would have stopped this 
>>occurrence?
>>
>
> Would a switch cover not delay ready access to the switch? Sounds like it 
> needs to be relocated for safety, and kept quick to select.
>
>
Steve R
June 26th 07, 07:47 PM
"Hawkdoc" > wrote in message 
...
> Instead of a covered switch, use a swich with raised side gaurds to 
> protect it. Can't think of any swiches used in most emergency procedures 
> that are covered.
>
> James
>
> Rule 6 - "Priorities are man made, not god made"
>
> "Maxwell" > wrote in message 
> ...
>>
>> "Stuart & Kathryn Fields" > wrote in message 
>> .. .
>>>A recent incident involving a Rotorway helicopter occurred.  An 
>>>accidental bumping of the clutch switch dis-engaged the clutch.  The 
>>>resulting autorotation resulted in a roll over and of course some 
>>>significant damage. As I understand it, the switch was mounted in the 
>>>overhead panel but the pilot's headset could make contact and 
>>>inadvertently cause the clutch dis-engagement.  I wonder if the standard 
>>>switch cover that you have to lift to get access to the switch itself 
>>>would have stopped this occurrence?
>>>
>>
>> Would a switch cover not delay ready access to the switch? Sounds like it 
>> needs to be relocated for safety, and kept quick to select.
>>
Hmmm, I'm going on the assumption that this is a switch that's flipped in 
order to apply a "clutch" type mechanism to engage the engine to the main 
drive system after it's been started.  On the Rotorway's I'm familiar with, 
that was simply an idler pulley that applied enough pressure to the main 
drive belts to prevent them from slippage and once engaged, was not 
disengaged until after the aircraft had landed and it was time to shut down. 
This was not a mechanism that would require any attention from the pilot 
while in flight, even during an emergency autorotation because the freewheel 
system that allows the rotor system to keep going after the engine quits was 
between the belts and the main drive systems.
Have they changed things, or did the owner of this particular bird change 
things?
Just curious!
Fly Safe,
Steve R.
Stuart & Kathryn Fields
June 26th 07, 10:42 PM
Steve:  Emergency autos frequently do not have the optimum landing zones 
available and the helicopter can turn over even after a successful auto to 
the ground.  A lot, and maybe the majority of helo pilots do not practice 
complete autos, but practice power recovery types and there is some more to 
be learned doing full down autos.  The Army found that practicing full down 
autos had more damage  and subsequent cost than not practicing them.
-- 
Stuart & Kathryn Fields, Publishers
Experimental Helo magazine
P. O. Box 1585
Inyokern, CA 93527
(760) 377-4478 ph
(760) 408-9747 publication cell
(760) 608-1299 technical cell
www.experimentalhelo.com
www.vkss.com
"Steve R" > wrote in message 
...
> "Stuart & Kathryn Fields" > wrote in message 
> .. .
>>A recent incident involving a Rotorway helicopter occurred.  An accidental 
>>bumping of the clutch switch dis-engaged the clutch.  The resulting 
>>autorotation resulted in a roll over and of course some significant 
>>damage. As I understand it, the switch was mounted in the overhead panel 
>>but the pilot's headset could make contact and inadvertently cause the 
>>clutch dis-engagement.  I wonder if the standard switch cover that you 
>>have to lift to get access to the switch itself would have stopped this 
>>occurrence?
>>
>> -- 
>> Stuart & Kathryn Fields, Publishers
>
> Sounds like a reasonable assumption to me.  It also sounds like having a 
> protected switch should be a recommended safety item for any critical 
> function, whether or not the switch is in a position to be accidentally 
> bumped.
>
> Going slightly off topic, and I'm not meaning to put anyone down here, but 
> why is it that just about every emergency autorotation I hear about 
> results in significant damage to the helicopter?  Most folks walk away 
> from them, which is good, but some don't.  This seems to be fairly common 
> even among aircraft that have the reputation of being relatively forgiving 
> in this mode.  Are autorotations "that" critical or are the successful 
> ones simply not considered to be worthy of news so I'm not hearing/reading 
> about them?
>
> Fly Safe,
> Steve R.
>
Maxwell
June 27th 07, 03:57 AM
"The OTHER Kevin in San Diego" <skiddz "AT" adelphia "DOT" net> wrote in 
message >>
>>Would a switch cover not delay ready access to the switch? Sounds like it
>>needs to be relocated for safety, and kept quick to select.
>>
> What would be the need to access the clutch switch in an emergency?
> If the clutch actuator fails, you typically pull the breaker so it
> can't change any more.
>
> In all the piston helis I've flown, there's a cover on the clutch
> switch and on some, a locking cover that physically holds the switch's
> bat in position.
>
Perhaps, but if the pilot has already hit it with his head, the cover will 
just make it a bigger obstacle. Next time it might pull his headset and hat 
over his eyes while landing.
It's personal preference for sure, but I really like the idea of having 
switches in plain site, easy reach, and out of the way.
Kind of makes me wonder though. If the pilot could have easily seen and 
reached the switch, could you reduce power and re-engage the clutch in time 
to possibly save an auto?
601XL Builder
June 29th 07, 08:23 PM
Steve R wrote:
> Going slightly off topic, and I'm not meaning to put anyone down here, but 
> why is it that just about every emergency autorotation I hear about results 
> in significant damage to the helicopter?  Most folks walk away from them, 
> which is good, but some don't.  This seems to be fairly common even among 
> aircraft that have the reputation of being relatively forgiving in this 
> mode.  Are autorotations "that" critical or are the successful ones simply 
> not considered to be worthy of news so I'm not hearing/reading about them?
I think it more because you just don't here about the ones that DON'T 
result in significant damage.
Steve R
June 29th 07, 11:10 PM
"601XL Builder" <wrDOTgiacona@suddenlinkDOTnet> wrote in message 
...
> Steve R wrote:
>
>> Going slightly off topic, and I'm not meaning to put anyone down here, 
>> but why is it that just about every emergency autorotation I hear about 
>> results in significant damage to the helicopter?  Most folks walk away 
>> from them, which is good, but some don't.  This seems to be fairly common 
>> even among aircraft that have the reputation of being relatively 
>> forgiving in this mode.  Are autorotations "that" critical or are the 
>> successful ones simply not considered to be worthy of news so I'm not 
>> hearing/reading about them?
>
> I think it more because you just don't here about the ones that DON'T 
> result in significant damage.
I truly hope so.  You see news reports of fixed wingers putting it down on 
an Interstate or something from time to time with no damage or injuries. 
Granted that's a little more noticeable than a helo successfully putting it 
down in a field somewhere but you'd think that one or two of them would show 
up on the local or national news "sometimes!"  The best I remember seeing 
was a Houston Police helicopter, a variant of the MD500, that did an 
emergency auto into a local high school football field.  The field was 
vacant at the time.  The aircraft remained on it's skids, which is what I 
found unique about this one, but was missing the tail boom just aft of the 
fuselage and had significant damage to the rotor system as a result of the 
blade strike.  All souls on board walked away with no injuries.
Fly Safe,
Steve R.
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