"Speed" helicopter
Josh
helicopter in the movie seems to have no torque compensation. There is no
tail rotor, only one main rotor, and it seems to be shaft driven (not tip
driven). Does anyone know what this helicopter uses for torque
compensation? (Awe, you like that movie anyway, go watch it :>)
PR
River - Xtreme Aviation wrote:
> NOTAR...Its a tailrotor system that eliminates anti-torque blades by using a
> stream of air through the tailboom...
>
> River
>
> "Xtreme...Life is too short not to be!"
>
> "Some of the most cruel lies are often those told in Silence. Truth may be
> blamed but cannot be ashamed."
> (Author Unknown)
John Armbrust
the tail boom meets the fuselage) that blows air down through the boom out
of a steerable nozzle at the end. It also uses the coanda effect from the
main rotor wash over the tail boom.
--
John W. Armbrust
Engineering Test Pilot
Steve Waltner <swal...@kscable.com> wrote in message
news:swaltner-101...@wks-213-043.kscable.com...
| In article <19991010201543...@ng-fd1.aol.com>,
| wingm...@aol.com (River - Xtreme Aviation) wrote:
|
| > NOTAR...Its a tailrotor system that eliminates anti-torque blades by
using a
| > stream of air through the tailboom...
| >
| >
| > River
| >
| > "Xtreme...Life is too short not to be!"
|
| The thrust on the tail of a NOTAR (NO TAil Rotor) helicopter doesn't
| really come from the air blowing through the tailboom on a NOTAR
| helicopter. The thrust is being produced by the downwash off the main
| rotor. The air being blown through the tailboom is released along a slot
| on the right side of the tailboom to control the airflow across the
| tailboom. This makes the downwash from the main rotor either come straight
| down or get pulled drastically to the left (when looking at the tair from
| behind the helicopter). This makes the tailboom itself generate lateral
| lift which counters the torque of the engine. I can't seem to track down
| the web page that describes this phenomenon. I keep thinking its called
| the coreolis effect, which is wrong since that's the reason water spins as
| it drains out of a tub.
|
| --
| Steve Waltner
| swal...@kscable.com
Loren Deichman
just one??
Loren
--
"I'd rather have a bottle in front of me than a frontal lobotomy."-- W.C.
Fields
John Armbrust <j.arm...@worldnet.att.net> wrote in message
news:7trfpd$7ha$2...@bgtnsc01.worldnet.att.net...
River - Xtreme Aviation
stream of air through the tailboom...
River
"Xtreme...Life is too short not to be!"
"Some of the most cruel lies are often those told in Silence. Truth may be
Steve Waltner
> NOTAR...Its a tailrotor system that eliminates anti-torque blades by using a
> stream of air through the tailboom...
>
>
> River
>
> "Xtreme...Life is too short not to be!"
The thrust on the tail of a NOTAR (NO TAil Rotor) helicopter doesn't
Bob Barbanes
properties of airflow which make the NOTAR possible.
Interestingly, experiments were done recently on a Bell UH-1 series in which a
spoiler was added to the length of the left side of the tailboom (which may be
a tremendous oversimplification) which stimulated a Coanda-Effect on the right
side, allowing for something like 10% less power required in a hover. Or
something like that. Details are hazy and I don't have the article close at
hand.
So although McDonnel Douglas may have utilized the Coanda Effect on their ship,
they by no means invented.
Brett Ogilvie
Hlywood
inquired about being an additional test bed. The stats look good for reducing power
to hover in high loading situations. I still would rather a tail rotor than a
NOTAR. The spoiler mod gives some promise for a compromise.
Chris Z
scott gardner
www.blrvgs.com for more info.
Scott Gardner
Shaber CJ
>NOTAR. The spoiler mod gives some promise for a compromise.
Why is that? Without a tail rotor the aircraft is much safer. You can stick
the boom into trees, brushes, water, all of which would cause and accident, but
with a NOTAR it is a non-event. Also there has never been a failure of the
NOTAR system. All in all a much safer aircraft.
Craig
Hlywood
power will not be an asset.
and DebrahC@ourhouse.net Mark C.
recovery. Now there is safety.
Linc
whole point is to keep the aircraft out of those situations. A pilot is what
makes the aircraft safer by flying it within the limits of the design. Not
by seeing how close to disaster he can come.
Linc
-----------
Avoid the rush, get to know God early!
Shaber CJ
>that much
>power will not be an asset.
>
Actually the NOTAR system takes less power in forward flight and roughly the
same as a standard tail rotor in hovering flight. What is the asset is not
having a tail rotor? The aircraft is quieter and does not have the liabilities
of a tail rotor.
Shaber CJ
>Why would you want to stick the tail rotor into trees, water, etc.? The
>whole point is to keep the aircraft out of those situations. A pilot is what
>makes the aircraft safer by flying it within the limits of the design. Not
>by seeing how close to disaster he can come.
>
>Linc
>
Ever heard the saying "shit happens"? Helimax has saved two accidents from
happening due to their operation of NOTARS. In one near accident the pilot
landed on an earthen dam to pick up a couple of hunters, the dam collapsed and
the tail hit the water before the pilot was able to recover. He hover taxied
to a slope and was able to load the hunters and fly safely away.
Linc
earthen dam? Yes, I'm second-guessing. I've heard the phrase about crap
occuring....but it usually has a couple of helping hands along the way. An
accident is never just one circumstance but a chain of circumstances that
remain unbroken leading to the accident.
Linc
-----------
Avoid the rush, get to know God early!
Shaber CJ wrote in message <19991013162456...@ng-cq1.aol.com>...
and DebrahC@ourhouse.net Mark C.
I have to disagree with that. In talking to the engineers at MD (the
one before Boeing and MD), they admitted to the tail taking up to 210
hp in hovering. I have hovered next to a NOTAR in a 500E with an "R"
engine (same as the one in the NOTAR), and was pulling over 15 lbs of
torque less. Do a rapid left pedal turn and watch the TOT. Heck of a
show.
Ask any of the L.A. County Sheriff pilots, they can only use the
500E's in the desert during the summer. The NOTAR's they have can not
handle the hot weather.
Shaber CJ
>one before Boeing and MD), they admitted to the tail taking up to 210
>hp in hovering. I have hovered next to a NOTAR in a 500E with an "R"
>engine (same as the one in the NOTAR), and was pulling over 15 lbs of
>torque less. Do a rapid left pedal turn and watch the TOT. Heck of a
>show.
>
>Ask any of the L.A. County Sheriff pilots, they can only use the
>500E's in the desert during the summer. The NOTAR's they have can not
>handle the hot weather.
>
impressed.
and DebrahC@ourhouse.net Mark C.
The 600N is hell on the body for any length of time flying (really
need that hydraulic system). Due to the transmission limits, it really
can not carry that much. I have never seen so many pilots run the
opposite direction when they may have to fly the 600N. Got to love
that tuck in a right turn.
Ask Border patrol, the pilots hate them. San Bernadino Sheriff is
going to fly theirs out and get rid of it as soon as possible. L.A.
County Sheriff's with the usual police equipment plus another monitor
can only carry three people. Heck, with full fuel, it has the same
payload as the 520N. They have more "power", but really no
improvement.
Robert Erdos
unimportant to forward speed, since most designs offload the tail rotor in
forward flight. The usual solution is a canted vertical stab. The biggest
liability of the tail rotor is the parasitic drag of a propellor going
"sideways". In that regard the NOTAR has real advantages.
Rob Erdos
robert...@nrc.ca
Beavis
Sage <sag...@erie.net> writes
>
>
>On Sat, 16 Oct 1999, Beavis wrote:
>
>> In article <Pine.BSI.4.05L.99101...@moose.erie.net>,
>> Sage <sag...@erie.net> writes
>> >
>> > There's an engine driven axial fan where the tail boom joins the
>> >fuselage. The yaw thrust is genrated by both the air exhausting through
>> >the moveable vent at the end of the tail boom and diversion of the main
>> >rotor flow by the air exhausting through the slot along the tail boom due
>> >to the Coanda effect.
>>
>> So what happens to your yaw control if the donkey quits?
>
>
> Okay, driven by the engine through the main transmission, just
>like a tail rotor.
That's cheered me up no end Sage. I had visions of rapidly rotating
NOTAR helicopters dropping in from the Heavens COMPLETELY unannounced:)
Beav
flyi...@my-deja.com
21,000 hours ago, I made similar statements! I don't anymore after
learning a little more about flying helicopters. More than 8000 hrs in
the rascals doing what they were designed for...as in utility work in
hostile environment. As someone else said...shit happens and it doesn't
matter how good you are when components fail. Lets keep it all in
perspective?
FlyinRock Ol Shy & Bashful
In article <rw%M3.33$hV5....@news.n-link.com>,
"Linc" <linc...@n-link.com> wrote:
> Why would you want to stick the tail rotor into trees, water, etc.?
The
> whole point is to keep the aircraft out of those situations. A pilot
is what
> makes the aircraft safer by flying it within the limits of the
design. Not
> by seeing how close to disaster he can come.
>
>
> -----------
> Avoid the rush, get to know God early!
>
> >
> >> >I still would rather a tail rotor than a
> >> >NOTAR. The spoiler mod gives some promise for a compromise.
> >>
> >> Why is that? Without a tail rotor the aircraft is much safer.
You can
> stick
> >> the boom into trees, brushes, water, all of which would cause and
> accident, but
> >> with a NOTAR it is a non-event. Also there has never been a
failure of
> the
> >> NOTAR system. All in all a much safer aircraft.
> >>
> >> Craig
> >
>
>
Sent via Deja.com http://www.deja.com/
Before you buy.