View Full Version : Question for the helicopter fans???
Andrew-S
December 10th 06, 09:42 AM
The other day one of the police departments that I work with mentioned that 
another PD aviation section had an "overspin" on their helicopter..  I was 
going to ask at the time what an overspin was but I forgot...  So my 
question is what exactly is an overspin???  I checked the web and the 
answers I found where not exactly enlightening...
Many thanks,
Andrew
Luke
December 10th 06, 10:05 AM
"Andrew-S" <I-Still-Hate-Spammers@Sorry-I had-to-leave-for-bit.com> wrote in
message  ...
> The other day one of the police departments that I work with mentioned
that
> another PD aviation section had an "overspin" on their helicopter..  I was
> going to ask at the time what an overspin was but I forgot...  So my
> question is what exactly is an overspin???  I checked the web and the
> answers I found where not exactly enlightening...
>
    Rotor RPM limit exceeded.
    Luke
Luke
December 10th 06, 10:05 AM
"Andrew-S" <I-Still-Hate-Spammers@Sorry-I had-to-leave-for-bit.com> wrote in
message  ...
> The other day one of the police departments that I work with mentioned
that
> another PD aviation section had an "overspin" on their helicopter..  I was
> going to ask at the time what an overspin was but I forgot...  So my
> question is what exactly is an overspin???  I checked the web and the
> answers I found where not exactly enlightening...
>
    Rotor RPM limit exceeded.
    Luke
alf blume
December 10th 06, 10:10 AM
"Andrew-S" <I-Still-Hate-Spammers@Sorry-I had-to-leave-for-bit.com> skrev i 
en meddelelse  ...
> The other day one of the police departments that I work with mentioned 
> that
> another PD aviation section had an "overspin" on their helicopter..  I was
> going to ask at the time what an overspin was but I forgot...  So my
> question is what exactly is an overspin???  I checked the web and the
> answers I found where not exactly enlightening...
I'll venture a guess:
The rotor presumably has a maximum rpm. It is possible to overspin the rotor 
if you decend very rapidly . .
A Police-helicopter can do that when they decend to check occupants in cars 
they are persuing - or if they have an engine failure, in which case you 
spin-up the rotor during the decend to make sure you have lift enough for 
the landing.
It's called "autorotation"  -  I've tried it as a passenger in a Hughes OH-6 
during a training flight, pretty scary.
Regards   Alf
alf blume
December 10th 06, 10:10 AM
"Andrew-S" <I-Still-Hate-Spammers@Sorry-I had-to-leave-for-bit.com> skrev i 
en meddelelse  ...
> The other day one of the police departments that I work with mentioned 
> that
> another PD aviation section had an "overspin" on their helicopter..  I was
> going to ask at the time what an overspin was but I forgot...  So my
> question is what exactly is an overspin???  I checked the web and the
> answers I found where not exactly enlightening...
I'll venture a guess:
The rotor presumably has a maximum rpm. It is possible to overspin the rotor 
if you decend very rapidly . .
A Police-helicopter can do that when they decend to check occupants in cars 
they are persuing - or if they have an engine failure, in which case you 
spin-up the rotor during the decend to make sure you have lift enough for 
the landing.
It's called "autorotation"  -  I've tried it as a passenger in a Hughes OH-6 
during a training flight, pretty scary.
Regards   Alf
Andrew-S
December 10th 06, 10:26 AM
Many thanks...
Alf
"alf blume" > wrote in message 
. ..
>
> "Andrew-S" <I-Still-Hate-Spammers@Sorry-I had-to-leave-for-bit.com> skrev 
> i en meddelelse  ...
>> The other day one of the police departments that I work with mentioned 
>> that
>> another PD aviation section had an "overspin" on their helicopter..  I 
>> was
>> going to ask at the time what an overspin was but I forgot...  So my
>> question is what exactly is an overspin???  I checked the web and the
>> answers I found where not exactly enlightening...
>
> I'll venture a guess:
> The rotor presumably has a maximum rpm. It is possible to overspin the 
> rotor if you decend very rapidly . .
> A Police-helicopter can do that when they decend to check occupants in 
> cars they are persuing - or if they have an engine failure, in which case 
> you spin-up the rotor during the decend to make sure you have lift enough 
> for the landing.
> It's called "autorotation"  -  I've tried it as a passenger in a Hughes 
> OH-6 during a training flight, pretty scary.
>
>
> Regards   Alf
>
>
Andrew-S
December 10th 06, 10:26 AM
Many thanks...
Alf
"alf blume" > wrote in message 
. ..
>
> "Andrew-S" <I-Still-Hate-Spammers@Sorry-I had-to-leave-for-bit.com> skrev 
> i en meddelelse  ...
>> The other day one of the police departments that I work with mentioned 
>> that
>> another PD aviation section had an "overspin" on their helicopter..  I 
>> was
>> going to ask at the time what an overspin was but I forgot...  So my
>> question is what exactly is an overspin???  I checked the web and the
>> answers I found where not exactly enlightening...
>
> I'll venture a guess:
> The rotor presumably has a maximum rpm. It is possible to overspin the 
> rotor if you decend very rapidly . .
> A Police-helicopter can do that when they decend to check occupants in 
> cars they are persuing - or if they have an engine failure, in which case 
> you spin-up the rotor during the decend to make sure you have lift enough 
> for the landing.
> It's called "autorotation"  -  I've tried it as a passenger in a Hughes 
> OH-6 during a training flight, pretty scary.
>
>
> Regards   Alf
>
>
Conscious Pilate
December 10th 06, 10:45 AM
G'day All,
this occurs only if the main rotor blades are not correctly aligned & 
tracked - I have had it occur once when after many hours of boring 
tracking - i.e. they put strobe reflecting bits on the end of the blades - 
for say a 3 bladed job the strobe thingos are sorta like this  - | _ / - you 
as a pilot pull it into a 3' hover & hold it - the maintenance bloke aims 
his strobe gun on the main rotors usually sitting on the top of a ladder - 
notes stuff arcane stuff in his little book - sees which one of the 3 is 
higher or lower. Then we land the helicopter - shut it down & the LAME makes 
adjustments to all the nuts & bolts on the main rotor hub & the process is 
repeated - sometimes for an agonising period.
Then ya go out & fly it - with the LAMe sitting in with ya - you then put it 
into an autorotation & if the blades have been tracked successfully then the 
main rotor RPM should stabilise at the max RPM red line.
So I suppose what I am trying to say is that if you experience a main rotor 
overspeed then the maintenance of the machine is a bit of a worry. I still 
have the bolt that was removed from the offending blade - it was cracked all 
the way through - so it is really a very serious problem to experience a 
main rotor overspeed.
see ya
Conscious Pilate
P.S. Your total logged time for about 3 hrs work is usually about 15mins!!
Conscious Pilate
December 10th 06, 10:45 AM
G'day All,
this occurs only if the main rotor blades are not correctly aligned & 
tracked - I have had it occur once when after many hours of boring 
tracking - i.e. they put strobe reflecting bits on the end of the blades - 
for say a 3 bladed job the strobe thingos are sorta like this  - | _ / - you 
as a pilot pull it into a 3' hover & hold it - the maintenance bloke aims 
his strobe gun on the main rotors usually sitting on the top of a ladder - 
notes stuff arcane stuff in his little book - sees which one of the 3 is 
higher or lower. Then we land the helicopter - shut it down & the LAME makes 
adjustments to all the nuts & bolts on the main rotor hub & the process is 
repeated - sometimes for an agonising period.
Then ya go out & fly it - with the LAMe sitting in with ya - you then put it 
into an autorotation & if the blades have been tracked successfully then the 
main rotor RPM should stabilise at the max RPM red line.
So I suppose what I am trying to say is that if you experience a main rotor 
overspeed then the maintenance of the machine is a bit of a worry. I still 
have the bolt that was removed from the offending blade - it was cracked all 
the way through - so it is really a very serious problem to experience a 
main rotor overspeed.
see ya
Conscious Pilate
P.S. Your total logged time for about 3 hrs work is usually about 15mins!!
December 10th 06, 05:26 PM
Aree on the   Rotor RPM limit exceeded.
But practice autos are a kick in the ass for fun.  Best e ticket ride
you can ge as a helo crewman.
On Sun, 10 Dec 2006 10:10:45 +0100, "alf blume"
> wrote:
>
>"Andrew-S" <I-Still-Hate-Spammers@Sorry-I had-to-leave-for-bit.com> skrev i 
>en meddelelse  ...
>> The other day one of the police departments that I work with mentioned 
>> that
>> another PD aviation section had an "overspin" on their helicopter..  I was
>> going to ask at the time what an overspin was but I forgot...  So my
>> question is what exactly is an overspin???  I checked the web and the
>> answers I found where not exactly enlightening...
>
>I'll venture a guess:
>The rotor presumably has a maximum rpm. It is possible to overspin the rotor 
>if you decend very rapidly . .
>A Police-helicopter can do that when they decend to check occupants in cars 
>they are persuing - or if they have an engine failure, in which case you 
>spin-up the rotor during the decend to make sure you have lift enough for 
>the landing.
>It's called "autorotation"  -  I've tried it as a passenger in a Hughes OH-6 
>during a training flight, pretty scary.
>
>
>Regards   Alf 
>
December 10th 06, 05:26 PM
Aree on the   Rotor RPM limit exceeded.
But practice autos are a kick in the ass for fun.  Best e ticket ride
you can ge as a helo crewman.
On Sun, 10 Dec 2006 10:10:45 +0100, "alf blume"
> wrote:
>
>"Andrew-S" <I-Still-Hate-Spammers@Sorry-I had-to-leave-for-bit.com> skrev i 
>en meddelelse  ...
>> The other day one of the police departments that I work with mentioned 
>> that
>> another PD aviation section had an "overspin" on their helicopter..  I was
>> going to ask at the time what an overspin was but I forgot...  So my
>> question is what exactly is an overspin???  I checked the web and the
>> answers I found where not exactly enlightening...
>
>I'll venture a guess:
>The rotor presumably has a maximum rpm. It is possible to overspin the rotor 
>if you decend very rapidly . .
>A Police-helicopter can do that when they decend to check occupants in cars 
>they are persuing - or if they have an engine failure, in which case you 
>spin-up the rotor during the decend to make sure you have lift enough for 
>the landing.
>It's called "autorotation"  -  I've tried it as a passenger in a Hughes OH-6 
>during a training flight, pretty scary.
>
>
>Regards   Alf 
>
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