Trex 450 Autorotation

[Larry]

Has anyone ever had a successful autorotation with a Trex450 with wooden blades (335mm). I an use to larger 60 size helicopters and have been successful with them (Lot of energy stored in that rotor). I try with the Trex and it just drops like a rock and loosed rotor speed almost immediately. I just power back up at 25 feet and just about miss the ground. I hope I never need to do one in a situation where I can't turn the motor back on. Any advice would be helpful.

[funfly3]

Larry wrote:
> Has anyone ever had a successful autorotation with a Trex450 with wooden
> blades (335mm). I an use to larger 60 size helicopters and have been
> successful with them (Lot of energy stored in that rotor). I try with
> the Trex and it just drops like a rock and loosed rotor speed almost
> immediately. I just power back up at 25 feet and just about miss the
> ground. I hope I never need to do one in a situation where I can't turn
> the motor back on. Any advice would be helpful.
I am not an expert but do you have enough negative pitch??

[Larry]

About 10 Degrees. But before I even get to respond and go to negative pitch
the rotor has slowed so much that it becomes impossible to get any cyclic
response. Rotor RPM about 2200 before I shut the motor down.

"funfly3" <dontemailme@ntlworld.com> wrote in message
news:g3G%h.9410$d9.7771@newsfe6-gui.ntli.net...
> Larry wrote:
>> Has anyone ever had a successful autorotation with a Trex450 with wooden
>> blades (335mm). I an use to larger 60 size helicopters and have been
>> successful with them (Lot of energy stored in that rotor). I try with the
>> Trex and it just drops like a rock and loosed rotor speed almost
>> immediately. I just power back up at 25 feet and just about miss the
>> ground. I hope I never need to do one in a situation where I can't turn
>> the motor back on. Any advice would be helpful.
> I am not an expert but do you have enough negative pitch??

[The OTHER Kevin in San Diego]

On Mon, 7 May 2007 09:39:04 -0400, "Larry" <me@you.net> wrote:

>Has anyone ever had a successful autorotation with a Trex450 with wooden blades (335mm). I an use to larger 60 size helicopters and have been successful with them (Lot of energy stored in that rotor). I try with the Trex and it just drops like a rock and loosed rotor speed almost immediately. I just power back up at 25 feet and just about miss the ground. I hope I never need to do one in a situation where I can't turn the motor back on. Any advice would be helpful.

Forward speed and not too much negative pitch. Too much negative and
you're adding drag to the blades. Forward speed will "bank" energy
you can use for the flare and setdown. Dropping the nose will kill
your RPM. Keep the nose up but not so far as you kill your forward
momentum.

The harder your flare at the bottom, the more you'll load up the head
and generate from "free" RPM. Just don't balloon when you flare..
Pull the nose up to stop the descent and then bleed off speed while
paralleling the ground. Once you're almost stopped, level the skids
and feed in the collective to cushion the landing. You're going to
need to be less than 2' off the ground at the end of the flare or it's
gonna drop to the ground.

What's your headpseed in a hover? If you're running low-mid 2000s,
you're "behind" the curve for autos in a small ship like this. 450s
are hard to auto, but if you get the headspeed up near 3000 RPM you've
got a bit more energy stored before you enter the auto.

[Larry]

I am at 2200 RPM in a hover. That is the recommended max. on the package the
blades come in.

"The OTHER Kevin in San Diego" <skiddz "AT" adelphia "DOT" net> wrote in
message news:p2mu339b8h7oitvuvc01nruprbr5nf0gtt@4ax.com...
> On Mon, 7 May 2007 09:39:04 -0400, "Larry" <me@you.net> wrote:
>
>>Has anyone ever had a successful autorotation with a Trex450 with wooden
>>blades (335mm). I an use to larger 60 size helicopters and have been
>>successful with them (Lot of energy stored in that rotor). I try with the
>>Trex and it just drops like a rock and loosed rotor speed almost
>>immediately. I just power back up at 25 feet and just about miss the
>>ground. I hope I never need to do one in a situation where I can't turn
>>the motor back on. Any advice would be helpful.
>
> Forward speed and not too much negative pitch. Too much negative and
> you're adding drag to the blades. Forward speed will "bank" energy
> you can use for the flare and setdown. Dropping the nose will kill
> your RPM. Keep the nose up but not so far as you kill your forward
> momentum.
>
> The harder your flare at the bottom, the more you'll load up the head
> and generate from "free" RPM. Just don't balloon when you flare..
> Pull the nose up to stop the descent and then bleed off speed while
> paralleling the ground. Once you're almost stopped, level the skids
> and feed in the collective to cushion the landing. You're going to
> need to be less than 2' off the ground at the end of the flare or it's
> gonna drop to the ground.
>
> What's your headpseed in a hover? If you're running low-mid 2000s,
> you're "behind" the curve for autos in a small ship like this. 450s
> are hard to auto, but if you get the headspeed up near 3000 RPM you've
> got a bit more energy stored before you enter the auto.
>

[Steve R]

Yeah, what he said! :-)

-10 degrees is WAY too much. -4 to 5 should be a maximum I would think.
The little birds simply don't carry the rotor inertia that the bigger ones
do so autos will always be problematic on them but they can do it if needed
and the pilot keeps his act together.

As far as rpms go, don't think that just because you're running 3000 rpm in
powered flight, that that's what you're going to get in autorotative flight.
Measuring autorotative rpms in something like a T-Rex would be almost
impossible. Things just happen too fast. I can tell you that, regardless
of how fast you're turning that 30 to 60/90 size bird in powered flight,
once you enter the autorotation, you're going to be down around 1450 within
the first 3 to 5 seconds. We've tached about a dozen different models and
this worked out to be the case no matter what. We had a 60 size bird
spinning between 1950 and 2000 rpm, flipped throttle hold and they hadn't
dropped 10% of their altitude and the rotor stabilized at 1450, give or take
a little depending on where the pilot was holding the collective. I can't
imagine that the micros are doing much better.

JMO! :-)

Fly Safe,
Steve R.


"The OTHER Kevin in San Diego" <skiddz "AT" adelphia "DOT" net> wrote in
message news:p2mu339b8h7oitvuvc01nruprbr5nf0gtt@4ax.com...
> On Mon, 7 May 2007 09:39:04 -0400, "Larry" <me@you.net> wrote:
>
>>Has anyone ever had a successful autorotation with a Trex450 with wooden
>>blades (335mm). I an use to larger 60 size helicopters and have been
>>successful with them (Lot of energy stored in that rotor). I try with the
>>Trex and it just drops like a rock and loosed rotor speed almost
>>immediately. I just power back up at 25 feet and just about miss the
>>ground. I hope I never need to do one in a situation where I can't turn
>>the motor back on. Any advice would be helpful.
>
> Forward speed and not too much negative pitch. Too much negative and
> you're adding drag to the blades. Forward speed will "bank" energy
> you can use for the flare and setdown. Dropping the nose will kill
> your RPM. Keep the nose up but not so far as you kill your forward
> momentum.
>
> The harder your flare at the bottom, the more you'll load up the head
> and generate from "free" RPM. Just don't balloon when you flare..
> Pull the nose up to stop the descent and then bleed off speed while
> paralleling the ground. Once you're almost stopped, level the skids
> and feed in the collective to cushion the landing. You're going to
> need to be less than 2' off the ground at the end of the flare or it's
> gonna drop to the ground.
>
> What's your headpseed in a hover? If you're running low-mid 2000s,
> you're "behind" the curve for autos in a small ship like this. 450s
> are hard to auto, but if you get the headspeed up near 3000 RPM you've
> got a bit more energy stored before you enter the auto.
>

[The OTHER Kevin in San Diego]

On Mon, 7 May 2007 19:43:04 -0400, "Larry" <me@you.net> wrote:

>I am at 2200 RPM in a hover. That is the recommended max. on the package the
>blades come in.

Which blades? The Pro Woodies will tolerate RPMs in the neighborhood
of 3000 but I STRONGLY suggest you epoxy the grip reinforcements to
the blades and BALANCE them before you spool up. I fly the Pro Woods
or Maverik M4s on my 450SE at 3000RPM in a hover. I have yet to shed
a blade. That's *MY* experience and I suggest you proceed with
caution if you bump the head speed up.

The Align CF blades (not the carbon "look" or those awful plastic
"carbon" blades will take 3000+ RPM easily.

My 450SEV2 runs the Align CF blades at a tick over 3100 RPM in a
hover. Zero problems thus far.

[The OTHER Kevin in San Diego]

On Tue, 8 May 2007 08:42:29 -0500, "Steve R"
<srhodes13@houston.rr.nospam.com> wrote:

>Yeah, what he said! :-)
>
>-10 degrees is WAY too much. -4 to 5 should be a maximum I would think.
>The little birds simply don't carry the rotor inertia that the bigger ones
>do so autos will always be problematic on them but they can do it if needed
>and the pilot keeps his act together.
>
>As far as rpms go, don't think that just because you're running 3000 rpm in
>powered flight, that that's what you're going to get in autorotative flight.
>Measuring autorotative rpms in something like a T-Rex would be almost
>impossible. Things just happen too fast. I can tell you that, regardless
>of how fast you're turning that 30 to 60/90 size bird in powered flight,
>once you enter the autorotation, you're going to be down around 1450 within
>the first 3 to 5 seconds. We've tached about a dozen different models and
>this worked out to be the case no matter what. We had a 60 size bird
>spinning between 1950 and 2000 rpm, flipped throttle hold and they hadn't
>dropped 10% of their altitude and the rotor stabilized at 1450, give or take
>a little depending on where the pilot was holding the collective. I can't
>imagine that the micros are doing much better.
>
>JMO! :-)

Now that's interesting. I think I might check that out myself when I
fly Saturday. I'd be surprised if the smaller ships didn't turn a bit
faster in an auto...

[Steve R]

"The OTHER Kevin in San Diego" <skiddz "AT" adelphia "DOT" net> wrote in
message news:qer343tlcn41ttstj5koja1ufbjpuot8pe@4ax.com...
> On Tue, 8 May 2007 08:42:29 -0500, "Steve R"
> <srhodes13@houston.rr.nospam.com> wrote:
>
>>Yeah, what he said! :-)
>>
>>-10 degrees is WAY too much. -4 to 5 should be a maximum I would think.
>>The little birds simply don't carry the rotor inertia that the bigger ones
>>do so autos will always be problematic on them but they can do it if
>>needed
>>and the pilot keeps his act together.
>>
>>As far as rpms go, don't think that just because you're running 3000 rpm
>>in
>>powered flight, that that's what you're going to get in autorotative
>>flight.
>>Measuring autorotative rpms in something like a T-Rex would be almost
>>impossible. Things just happen too fast. I can tell you that, regardless
>>of how fast you're turning that 30 to 60/90 size bird in powered flight,
>>once you enter the autorotation, you're going to be down around 1450
>>within
>>the first 3 to 5 seconds. We've tached about a dozen different models and
>>this worked out to be the case no matter what. We had a 60 size bird
>>spinning between 1950 and 2000 rpm, flipped throttle hold and they hadn't
>>dropped 10% of their altitude and the rotor stabilized at 1450, give or
>>take
>>a little depending on where the pilot was holding the collective. I can't
>>imagine that the micros are doing much better.
>>
>>JMO! :-)
>
> Now that's interesting. I think I might check that out myself when I
> fly Saturday. I'd be surprised if the smaller ships didn't turn a bit
> faster in an auto...
>

After re-reading my statement and then your response, I'd like to clarify
that I don't think the micro is getting down to 1450. What I wrote "could"
be interpreted that way and it's not what I meant. I'll I was trying to say
is that I'm not sure that the micro will maintain that 3000 rpm, powered
rotor speed in a stable autorotative state. I could certainly be wrong
about that but as explained above, my experience with the larger birds would
imply that it probably won't.

Kevin, if you tach a 30 or larger model in powered flight and then in an
autorotation, I'd be very interested in what your results are. I'm sure a
lot of that depends on the pilots techniques. My friend and I love doing
auto's. We both tend to play the collective a bit on the descent. We don't
bottom out the collective and let it drop like a rock and we don't try to
float them too much either. If you and whoever winds up helping you in this
does things differently, you'll certainly get different results.

If you manage to get a solid reading on a T-Rex in a stable autorotative
state, I'd "really" like to see what numbers you come up with. You'll have
to start high as those little suckers drop like a rock when you cut power!
:-)

Fly Safe,
Steve R.

[Larry]

You are not kidding when you say those little suckers drop like a rock !


"Steve R" <srhodes13@houston.rr.nospam.com> wrote in message
news:4643e6ee$0$27046$4c368faf@roadrunner.com...
> "The OTHER Kevin in San Diego" <skiddz "AT" adelphia "DOT" net> wrote in
> message news:qer343tlcn41ttstj5koja1ufbjpuot8pe@4ax.com...
>> On Tue, 8 May 2007 08:42:29 -0500, "Steve R"
>> <srhodes13@houston.rr.nospam.com> wrote:
>>
>>>Yeah, what he said! :-)
>>>
>>>-10 degrees is WAY too much. -4 to 5 should be a maximum I would think.
>>>The little birds simply don't carry the rotor inertia that the bigger
>>>ones
>>>do so autos will always be problematic on them but they can do it if
>>>needed
>>>and the pilot keeps his act together.
>>>
>>>As far as rpms go, don't think that just because you're running 3000 rpm
>>>in
>>>powered flight, that that's what you're going to get in autorotative
>>>flight.
>>>Measuring autorotative rpms in something like a T-Rex would be almost
>>>impossible. Things just happen too fast. I can tell you that,
>>>regardless
>>>of how fast you're turning that 30 to 60/90 size bird in powered flight,
>>>once you enter the autorotation, you're going to be down around 1450
>>>within
>>>the first 3 to 5 seconds. We've tached about a dozen different models
>>>and
>>>this worked out to be the case no matter what. We had a 60 size bird
>>>spinning between 1950 and 2000 rpm, flipped throttle hold and they hadn't
>>>dropped 10% of their altitude and the rotor stabilized at 1450, give or
>>>take
>>>a little depending on where the pilot was holding the collective. I
>>>can't
>>>imagine that the micros are doing much better.
>>>
>>>JMO! :-)
>>
>> Now that's interesting. I think I might check that out myself when I
>> fly Saturday. I'd be surprised if the smaller ships didn't turn a bit
>> faster in an auto...
>>
>
> After re-reading my statement and then your response, I'd like to clarify
> that I don't think the micro is getting down to 1450. What I wrote
> "could" be interpreted that way and it's not what I meant. I'll I was
> trying to say is that I'm not sure that the micro will maintain that 3000
> rpm, powered rotor speed in a stable autorotative state. I could
> certainly be wrong about that but as explained above, my experience with
> the larger birds would imply that it probably won't.
>
> Kevin, if you tach a 30 or larger model in powered flight and then in an
> autorotation, I'd be very interested in what your results are. I'm sure a
> lot of that depends on the pilots techniques. My friend and I love doing
> auto's. We both tend to play the collective a bit on the descent. We
> don't bottom out the collective and let it drop like a rock and we don't
> try to float them too much either. If you and whoever winds up helping
> you in this does things differently, you'll certainly get different
> results.
>
> If you manage to get a solid reading on a T-Rex in a stable autorotative
> state, I'd "really" like to see what numbers you come up with. You'll
> have to start high as those little suckers drop like a rock when you cut
> power! :-)
>
> Fly Safe,
> Steve R.
>

[The OTHER Kevin in San Diego]

On Thu, 10 May 2007 22:46:09 -0500, "Steve R"
<srhodes13@houston.rr.nospam.com> wrote:


>After re-reading my statement and then your response, I'd like to clarify
>that I don't think the micro is getting down to 1450. What I wrote "could"
>be interpreted that way and it's not what I meant. I'll I was trying to say
>is that I'm not sure that the micro will maintain that 3000 rpm, powered
>rotor speed in a stable autorotative state. I could certainly be wrong
>about that but as explained above, my experience with the larger birds would
>imply that it probably won't.

Oh, I'd be willing to bet large sums of money that 3000 RPM headspeed
won't remain in an auto. My point was that high speed would give you
a little more "breathing room" to get established in the auto before
RPM decayed to the point where the heli is no longer generating any
lift. Running 2200 RPM might give you (and I'm just tossing out
number here) 2 seconds to stabiize the auto where that extra 800 RPM
at entry might give you 3 seconds.

>Kevin, if you tach a 30 or larger model in powered flight and then in an
>autorotation, I'd be very interested in what your results are. I'm sure a
>lot of that depends on the pilots techniques. My friend and I love doing
>auto's. We both tend to play the collective a bit on the descent. We don't
>bottom out the collective and let it drop like a rock and we don't try to
>float them too much either. If you and whoever winds up helping you in this
>does things differently, you'll certainly get different results.

Well, I can tell you my Trex600 in an out of ground effect hover tachs
out right about 1900RPM on those crappy Align 4400 batteries. I
haven't checked it with the new Flightpower EVO25s I just got, but
will try to do so this weekend. My buddy's 600 on 8S and a Neu motor
tachs out at 2200 RPM in an OGE hover.

My 450SE is somewhere around 2900 RPM (tached by my 10 year old so
results are subjective at best. heheh) and my SEV2 is around 3100 RPM.
The SE has the 430L motor and 15C Thunderpower batteries and the V2
has the new 430XL motor and Align's 22C packs. Same pinion, throttle
and pitch curves on both.

>If you manage to get a solid reading on a T-Rex in a stable autorotative
>state, I'd "really" like to see what numbers you come up with. You'll have
>to start high as those little suckers drop like a rock when you cut power!
>:-)

I'll try and get some results this weekend. I'm going to a funfly
Saturday but not sure if I'm going to bring any helis or not. Those
things make me nervous about keeping an eye on my gear.. Sunday is
Mother's Day and I'm not sure I can get away to burn off a few packs
or if I can find someone to tach the heli for me. To be honest, I'm
not sure I want to try an auto with the 450s. heheh

[Larry]

I have a Kalt Gas Baron Alpha, Weedwacker Engine and 10 oz. of lead in the
ends of the rotor blades. I had this Heli since the late 80,s never crashed.
I can put this baby in a 10 foot hover cut the engine to idle and auto it
straight down nice and slow. It takes about 40 sec. for the rotor to stop
when on the ground and you go to idle. Into a head wind you can actually
turn and fly around in an autorotation. So when I go to my Trex 450 I an
coming to the conclusion that it is impossible to auto this heli.


"Steve R" <srhodes13@houston.rr.nospam.com> wrote in message
news:4643e6ee$0$27046$4c368faf@roadrunner.com...
> "The OTHER Kevin in San Diego" <skiddz "AT" adelphia "DOT" net> wrote in
> message news:qer343tlcn41ttstj5koja1ufbjpuot8pe@4ax.com...
>> On Tue, 8 May 2007 08:42:29 -0500, "Steve R"
>> <srhodes13@houston.rr.nospam.com> wrote:
>>
>>>Yeah, what he said! :-)
>>>
>>>-10 degrees is WAY too much. -4 to 5 should be a maximum I would think.
>>>The little birds simply don't carry the rotor inertia that the bigger
>>>ones
>>>do so autos will always be problematic on them but they can do it if
>>>needed
>>>and the pilot keeps his act together.
>>>
>>>As far as rpms go, don't think that just because you're running 3000 rpm
>>>in
>>>powered flight, that that's what you're going to get in autorotative
>>>flight.
>>>Measuring autorotative rpms in something like a T-Rex would be almost
>>>impossible. Things just happen too fast. I can tell you that,
>>>regardless
>>>of how fast you're turning that 30 to 60/90 size bird in powered flight,
>>>once you enter the autorotation, you're going to be down around 1450
>>>within
>>>the first 3 to 5 seconds. We've tached about a dozen different models
>>>and
>>>this worked out to be the case no matter what. We had a 60 size bird
>>>spinning between 1950 and 2000 rpm, flipped throttle hold and they hadn't
>>>dropped 10% of their altitude and the rotor stabilized at 1450, give or
>>>take
>>>a little depending on where the pilot was holding the collective. I
>>>can't
>>>imagine that the micros are doing much better.
>>>
>>>JMO! :-)
>>
>> Now that's interesting. I think I might check that out myself when I
>> fly Saturday. I'd be surprised if the smaller ships didn't turn a bit
>> faster in an auto...
>>
>
> After re-reading my statement and then your response, I'd like to clarify
> that I don't think the micro is getting down to 1450. What I wrote
> "could" be interpreted that way and it's not what I meant. I'll I was
> trying to say is that I'm not sure that the micro will maintain that 3000
> rpm, powered rotor speed in a stable autorotative state. I could
> certainly be wrong about that but as explained above, my experience with
> the larger birds would imply that it probably won't.
>
> Kevin, if you tach a 30 or larger model in powered flight and then in an
> autorotation, I'd be very interested in what your results are. I'm sure a
> lot of that depends on the pilots techniques. My friend and I love doing
> auto's. We both tend to play the collective a bit on the descent. We
> don't bottom out the collective and let it drop like a rock and we don't
> try to float them too much either. If you and whoever winds up helping
> you in this does things differently, you'll certainly get different
> results.
>
> If you manage to get a solid reading on a T-Rex in a stable autorotative
> state, I'd "really" like to see what numbers you come up with. You'll
> have to start high as those little suckers drop like a rock when you cut
> power! :-)
>
> Fly Safe,
> Steve R.
>

[Steve R]

"Larry" <me@you.net> wrote in message
news:3fOdnTvD1ebFl9jbnZ2dnUVZ_vyunZ2d@comcast.com. ..
>I have a Kalt Gas Baron Alpha, Weedwacker Engine and 10 oz. of lead in the
>ends of the rotor blades. I had this Heli since the late 80,s never
>crashed. I can put this baby in a 10 foot hover cut the engine to idle and
>auto it straight down nice and slow. It takes about 40 sec. for the rotor
>to stop when on the ground and you go to idle. Into a head wind you can
>actually turn and fly around in an autorotation. So when I go to my Trex
>450 I an coming to the conclusion that it is impossible to auto this heli.
>
>
Yup! Large helicopter + heavy rotor blades = long hang times at the bottom
of an autorotation. Great fun! :-)

The T-Rex (and similar) models aren't impossible to auto. I've seen too
many folks do it. However, you simply "do not" have the rotor inertia to
cushion the landing much and you have to take that into account. A
"healthy" wind to auto into is also a very good thing. I'd never
deliberately attempt an auto on a calm day with one of these birds. I've
only tried one autorotation with my HDX450. Everything happened "very"
quickly but for the most part, the approach was good. I even got a nice
spool up on the flare but I didn't get it level enough for the touchdown and
was rewarded with a healthy boom strike for my trouble. I haven't tried
another one yet but probably will eventually.

FWIW! :-)
Fly Safe,
Steve R.

[Larry]

I had 335mm blades 100 feet altitude 15 MPH head wind 35 MPH forward speed 5
Deg. negative pitch and this thing was 4 feet from the ground and falling
like a rock with no inertia left in the rotor. Powered back up just in time.
It fell in less then 2 sec. I have come to the conclusion it is impossible
to auto a Trex 450. I have a Blade CP Pro and can just about stop the rotor
with no throttle in normal mode and this think just floats around. The Trex
450 is a brick.

"Larry" <me@you.net> wrote in message
news:g8KdndYp4Ntv4NnbnZ2dnUVZ_tmknZ2d@comcast.com. ..
> You are not kidding when you say those little suckers drop like a rock !
>
>
> "Steve R" <srhodes13@houston.rr.nospam.com> wrote in message
> news:4643e6ee$0$27046$4c368faf@roadrunner.com...
>> "The OTHER Kevin in San Diego" <skiddz "AT" adelphia "DOT" net> wrote in
>> message news:qer343tlcn41ttstj5koja1ufbjpuot8pe@4ax.com...
>>> On Tue, 8 May 2007 08:42:29 -0500, "Steve R"
>>> <srhodes13@houston.rr.nospam.com> wrote:
>>>
>>>>Yeah, what he said! :-)
>>>>
>>>>-10 degrees is WAY too much. -4 to 5 should be a maximum I would think.
>>>>The little birds simply don't carry the rotor inertia that the bigger
>>>>ones
>>>>do so autos will always be problematic on them but they can do it if
>>>>needed
>>>>and the pilot keeps his act together.
>>>>
>>>>As far as rpms go, don't think that just because you're running 3000 rpm
>>>>in
>>>>powered flight, that that's what you're going to get in autorotative
>>>>flight.
>>>>Measuring autorotative rpms in something like a T-Rex would be almost
>>>>impossible. Things just happen too fast. I can tell you that,
>>>>regardless
>>>>of how fast you're turning that 30 to 60/90 size bird in powered flight,
>>>>once you enter the autorotation, you're going to be down around 1450
>>>>within
>>>>the first 3 to 5 seconds. We've tached about a dozen different models
>>>>and
>>>>this worked out to be the case no matter what. We had a 60 size bird
>>>>spinning between 1950 and 2000 rpm, flipped throttle hold and they
>>>>hadn't
>>>>dropped 10% of their altitude and the rotor stabilized at 1450, give or
>>>>take
>>>>a little depending on where the pilot was holding the collective. I
>>>>can't
>>>>imagine that the micros are doing much better.
>>>>
>>>>JMO! :-)
>>>
>>> Now that's interesting. I think I might check that out myself when I
>>> fly Saturday. I'd be surprised if the smaller ships didn't turn a bit
>>> faster in an auto...
>>>
>>
>> After re-reading my statement and then your response, I'd like to clarify
>> that I don't think the micro is getting down to 1450. What I wrote
>> "could" be interpreted that way and it's not what I meant. I'll I was
>> trying to say is that I'm not sure that the micro will maintain that 3000
>> rpm, powered rotor speed in a stable autorotative state. I could
>> certainly be wrong about that but as explained above, my experience with
>> the larger birds would imply that it probably won't.
>>
>> Kevin, if you tach a 30 or larger model in powered flight and then in an
>> autorotation, I'd be very interested in what your results are. I'm sure
>> a lot of that depends on the pilots techniques. My friend and I love
>> doing auto's. We both tend to play the collective a bit on the descent.
>> We don't bottom out the collective and let it drop like a rock and we
>> don't try to float them too much either. If you and whoever winds up
>> helping you in this does things differently, you'll certainly get
>> different results.
>>
>> If you manage to get a solid reading on a T-Rex in a stable autorotative
>> state, I'd "really" like to see what numbers you come up with. You'll
>> have to start high as those little suckers drop like a rock when you cut
>> power! :-)
>>
>> Fly Safe,
>> Steve R.
>>
>

[The OTHER Kevin in San Diego]

On Wed, 16 May 2007 18:51:04 -0400, "Larry" <me@you.net> wrote:

>I had 335mm blades 100 feet altitude 15 MPH head wind 35 MPH forward speed 5
>Deg. negative pitch and this thing was 4 feet from the ground and falling
>like a rock with no inertia left in the rotor. Powered back up just in time.
>It fell in less then 2 sec. I have come to the conclusion it is impossible
>to auto a Trex 450. I have a Blade CP Pro and can just about stop the rotor
>with no throttle in normal mode and this think just floats around. The Trex
>450 is a brick.

I saw several folks auto their 450s successfully this past weekend at
a local fun fly. I'd almost be willing to bet -5 degrees is too much
to keep driving the rotor blades or you let the nose drop - or a
combination of both..

[Steve R]

"The OTHER Kevin in San Diego" <skiddz "AT" adelphia "DOT" net> wrote in
message news:n05n43pthlqegkj2rjfv8s12538u9ea3jm@4ax.com...
> On Wed, 16 May 2007 18:51:04 -0400, "Larry" <me@you.net> wrote:
>
>>I had 335mm blades 100 feet altitude 15 MPH head wind 35 MPH forward speed
>>5
>>Deg. negative pitch and this thing was 4 feet from the ground and falling
>>like a rock with no inertia left in the rotor. Powered back up just in
>>time.
>>It fell in less then 2 sec. I have come to the conclusion it is impossible
>>to auto a Trex 450. I have a Blade CP Pro and can just about stop the
>>rotor
>>with no throttle in normal mode and this think just floats around. The
>>Trex
>>450 is a brick.
>
> I saw several folks auto their 450s successfully this past weekend at
> a local fun fly. I'd almost be willing to bet -5 degrees is too much
> to keep driving the rotor blades or you let the nose drop - or a
> combination of both..
>

Letting the nose drop is a definite no-no. You do that and you'll loose the
airflow that's supposed to keep the rotor turning. The rotor will then slow
down "RIGHT NOW!!!" and you'll have "NO" chance of recovering without the
reapplication of power. The model has to be kept level at the very least,
slightly nose high would be better. Enter the auto from moderate forward
flight (that's as it appears to travel over the ground) with a "healthy"
head wind. Lower the collective with power still applied and "then" flip
into throttle hold. Also make absolutely sure that the collective curves
and the cyclic trims are matched between throttle hold and whatever flight
mode you typically enter autorotations from. That will insure that the
model doesn't do anything unexpected when you change flight modes. Whether
or not -5 is too much negative pitch, I'm not sure, but I tend to agree that
it certainly could be. I don't think I'd go any lower than that on an
initial setup.

FWIW! ;-)

Fly Safe,
Steve R.

PS: Kevin, have any look taching that little sucker yet? :-D

[The OTHER Kevin in San Diego]

On Wed, 16 May 2007 19:30:52 -0500, "Steve R"
<srhodes13@houston.rr.nospam.com> wrote:



>PS: Kevin, have any look taching that little sucker yet? :-D

I've been trying, but each time I hold the viewport on the tach up to
my eye, I lose control of the helicopter. :)