NOTAR Systems

[Copter Cody]

To all,

Never mind what was posted here, it seems that since im only 17 i know nothing
Cody

[ 22 July 2001: Message edited by: Copter Cody ]

[sling load]

show us the statistics

[tigerpic]

notars are very quiet. really fantastic! and i myself had the pleasure of flying a corporate md600n for half an hour. it felt like flying a BIG h300 or a very fast enstrom f28, because of relatively large pedal inputs needed throughout a flight. no hydraulics and the pilot used to fly it with the four-way electric trim - although i was taught "never to fly the aircraft with the trim." the six bladed fully-articulated rotor system was very stabil and gave almost no vibrations. it was like floating (on a cloud) through the air. only problem, the pilot told me, autorotational airspeed is 85 knots. that doesn't give you much for a 180 deg turn if you need it. think about that, the 206b has 52 minimum in the handbook. i know optimum airspeed is a lot lower, but still.

now, little gossip from mexico city: the md-team was in mexico city to demonstrate the 600 performance. the helicopter came in for landing on a pinnacle, a building. as you might know, mexico city is located around 8000'. when the pilot ran out of left pedal pulling in power, the helicopter made at least a 180 degree turn by itself :eek: over the pad before the pilot was able to set it down. the demonstration flights were limited to a half hour radius and little weight inside the cockpit, to maintain positive control. :rolleyes:

anyway, that last story might just be rumours, so don't sue me, i'm still broke after heli training!

[Letsby Avenue]

The exact same thing happened to a Navy pilot many years ago whilst trying to fly an approach to a ridge in South Georgia unfortunately a few years later an army pilot managed to do the same thing in Saillagouse killing the crew in the process. Funny how pilots always pay more attention to Density Altitude and Weight and power limits after the event. If it really were the MD team demonstrating their machine then frankly they need their a**** kicked. IMHO of course. :rolleyes:

[md desert fan]

If you are really interested in the truth..... contact [email protected] he was flying and the story told here is not even close!

[djras]

Good Ol cody is now a NOTAR expert!!!null

[Copter Cody]

AbnerPilut-

What dp you mean by that?

Cody

[vaqueroaero]

After a slight technical hitch........
1) I believe that the Notar system is now about 10 years old.
2) The reason that 'you haven't had the pleasure of flying one yet' is that you are still in high school, haven't started flying training yet and, quite frankly, haven't got a clue what you are talking about.

[djras]

Vaqueroaero said it!! That's what I mean by that!

[FLIR]

Cody, I have some 170 hours on the MD902 explorer, and feel that you have indeed a quieter machine,but, the handling is a little ...... different !!!
Safety with these types is tops - providing you appreciate the flight characteristics of Coanda effect and the Notar system. All helicopters WILL bite given enough reason ( I hear what you say Letsby - I remember the prang only too well) I have run out of pedal in a very high wind - but the 902 is a big slab sided aircraft. You MUST know what is going on at ALL times ( brain ahead of machine ) and be prepared to counter limited power or control situations at the moment they occur.

FLIR

[Nick Lappos]

Copter Cody asked:
Who believes that the new NOTAR systems should be standard on most all single engine systems?

Nick sez:
Not the US Army. The NOTAR equipped OH-6's they tried were so poor they retrofitted them back with tail rotors. The NOTAR is really a very ineffecient tail rotor buried inside the tail cone, with enough lost energy to cost at least one passenger of payload in a 4 passenger aircraft. The noise is quite a bit lower, and it is clearly safer if you stick your tail into obstructions, so you have choices.

Cody said:
All of the statistics show that a machine with the NOTAR system is significantly safer as well as better handling and is much quiter. They say that the helicopter is more flyer-friendly.

Nick sez:
NOTARS are quirky and not particularly user friendly, that's why they need a built in stability system to quell their basically neutral stability. Nothing like swapping ends at 100 knots to make you disagree with Cody.

One great topic we could toss around is the concept of the natural give and take of design, where each attribute gives some benifit and costs some panalty. Beware of any question that front loads the attribute but forgets to mention the price tag. The best way to phrase the question is "Who wants to lose 20% of the payload of their helicopter to have a protected, quieter tail?" Some folks will say Yes, and that's OK, but at least they have answered the whole question.

[HeliMark]

I have about 700 hours in the MD520N. And about the only good thing about, it is safer on the ground (not in the air). It does not work well at altitude. Not stable in winds. Tail takes too much power...etc. Although the tail has the same authority as the MD500E, it reacts to inputs a lot slower. Just before going through transitional lift on landing, you need to pull a slight amount of collective in, and slight forward cyclic to stop the "ass tuck" it likes to do. You should see what the manuel says will happen if you have a tail problem (stuck thruster, pedal) get below 20kts, and you are not skidding on the ground.

Although I do not know what the winds were in Mexico, the MD600N has a critical wind azimuth in the limitation section that says that at high altitude and any weight, you can not have any wind on the right rear area. You can exceed the power limitations attempting to correct for the winds. That is a possibility of what may have happened.

Also, a lot of the police departments in the western U.S. are dumping their MD520's and MD600's they have. A fair amount of them are going back to MD500E's.

[sling load]

Cody,
Again,where are your statistics? I would love to see them please!

[sling load]

Thought so......................

[MightyGem]

Is there a limit to the size of a NOTAR helicopter?

[widgeon]

I would imagine that as it is an aerodynamic force that gives the antitorque ( flow of air around the tailboom ) , for a larger aircraft with more torque you would need a combination of larger diameter tailboom , longer tailboom ( 600 seems kinda long already) or greater air flow . I am sure there is a certain weight where the weight penalties would make the notar impractical . I was told eurocopter tried a fenestron on the Puma without much success. Anyone got any opinion as to if a notar would work on a 430 or S76 ?.
Just read Nicks post on the subject , Nick will they try fan in fin on the S76 ?

[ 21 July 2001: Message edited by: widgeon ]

[Copter Cody]

To Sling Load,

go to http://www.ntsb.gov/ntsb/Month.asp
See for your self, bye the way, patience is a virtue.

Cody

[djras]

Doesn't answer the question!!!

[Lama Bear]

"Copter" Cody,

Children should be seen and not heard.

Wait until you learn enough to be relevant, knowledgeable, and interesting before you post. You should be concentrating on getting out of high school instead of cluttering this and other forums with your chatter.

Did you really think that your post of the url for the NTSB monthly page was a legitimate answer to Sling Load's request for more facts?

Most everybody has given you the benefit of the doubt and tried to answer you questions. As far as I'm concerned you have used up that doubt.

[Nick Lappos]

Lama Bear said:
I would imagine that as it is an aerodynamic force that gives the antitorque ( flow of air around the tailboom ) , for a larger aircraft with more torque you would need a combination of larger diameter tailboom , longer tailboom ( 600 seems kinda long already) or greater air flow . I am sure there is a certain weight where the weight penalties would make the notar impractical .

Nick sez:
The NOTAR is actually only partly a Coanda flow tailboom anti-torque system, it also needs a tip thruster to help generate anti-torque. It cannot make it with either one alone. The tip thruster is very necessary because in many hover situations, the main rotor downwash does not flow over the tail at all (that is why the limitation on wind from the rear, where the wind blows the main rotor downwash forward, away from the tail.) The NOTAR has two virtues, protection and low noise, but it has a whole list of deficits, including its high power consumption, poor handling qualities, poor stability at high speed, wind speed limitations, mechanical complexity (many more moving critical parts than a tail rotor) and high weight. I'll bet it scales up quite poorly, but I have no data to back up that intuition.

Lama Bear asked:
I was told eurocopter tried a fenestron on the Puma without much success. Anyone got any opinion as to if a notar would work on a 430 or S76 ?.
Just read Nicks post on the subject , Nick will they try fan in fin on the S76 ?

Nick sez:
We looked at NOTAR for Comanche. In our studies, NOTAR had no advantage over the Fantail, and Fantail provided exceptional maneuverability, a real plus for the recon/attack mission.

We used the S-76 as the test bed for the fantail that is on the Comanche, and it worked quite well, but we had no intention of adapting it for the production S-76 family. It weighs a bit more (about 50 pounds) and because it must be mounted on the tail drive shaft axis, it protrudes down below the tail cone by a bunch, and presents more of a ground contact problem. Comanche has a tail wheel, and so has no such issue.

The Eurocopter folks told me that they did try to use a fenestron on a Puma as a development tool, and it dod not scale up well at all, and was abandoned.

[md 600 driver]

i have 60 hrs now on my 600 i find it to be marvellous .i dont realy have a problem . All helicopters have something that bites if you dont watch it ,but on inital training you are taught to be able to recognize these and you make sure that you do not get into these areas
the ysas mods will lighten the in flight workload i flew the 600 in usa with the ysas it was spot on

[sling load]

Copter Cody,
I think you had better do an assignment, ask the FAA how many notars are registered, then ask how many helicopters are registered, then do some basic maths and work out how many helicopters have had accidents in your statistics, then work out the percentage of each, then weigh up the percentage of notar and conventional helicopters that are in your country, do it as an assignment, you might get someone from the faa to do it for you if you ask! In the meantime, you want to tell the people here at pprune that patience is a virtue, lets get some stuff out in the open, Im over 35, been flying helis since i was seventeen and have an ATPL and over 4000 hours in m/e helis, ems/sar, long line, etc..

OK Copter Cody, Ive bared all,

Tell us , what do you have....Im very patient

Lama Bear, thank you.

[Lama Bear]

Hey Nick,

I think you've been flying sideways and backwards for too long. Those were very good answers but they aren't my questions. It was Widgeon that asked them.

[Nick Lappos]

Hey Lama Bear,

Sorry about that! I guess I was having a senior moment! All that sideward flying spins your gyros, y'know. :D

[HeliMark]

Copter Cody, just to give you a little taste of what people are talking about.
About a year ago, I did some accident figures for the place I work, as we were looking to replace our fleet.

The figures I have are not the most scientific, but pretty close. The figures were only based on the number of accidents and passengers on board. Of the accidents up to July of last year, 20% of the passengers injuries were fatal for the MD520N, the MD600N was 22%, and the MD500C/D/E was 14%. Total injuries (both fatal and non fatal) of those accidents were MD500 - 46%, MD520N - 67%, and MD600N - 56%. Remember, these aircrafts are generally not flown by new pilots either. Not really sure I like the 21% increase!

By the way, the A-Star's were 25%! Of course the A-Star carries more passengers per flight and these figures do not really show that.

Just do not look at a one month statistic. It really is unrealistic. And if you want to figure the statistics with the number of aircraft that are flying (how many thousands of 500's compared to what, less then 200 MD520's and MD600's).

[Copter Cody]

HeliMark-

Thanks for your input, i had know i idea that the people who Actually fly thought so much different. I guess that i need to rely on a better and more relyable site. Thanks

Cody

[Copter Cody]

Sling load,

Here is my final plee. Go to this website and see for yourself. I am not trying to be offencesive or a "know it all," Just trying to find an opinion.
http://www.mdhelicopters.com/Roto rcraft/Presentations/MD_Explorer_files/frame.htm (http://www.mdhelicopters.com/Rotorcraft/Presentations/MD_Explorer_files/frame.htm)
Then go to NOTAR systems on the side, there you should find some MD Company statistics. You have heard of McDonnell Douglas haven't you? If you want further information just work your way along with the other facts
I hope this is what you wanted.

[ 23 July 2001: Message edited by: Copter Cody ]

[sling load]

Copter Cody,
You are saying the statistics you are quoting are from the MD website, and they claim an independent study btwn 1988 to 1994 of s/e turbines found that 21% of helicopter accidents are attributable to tail rotor accidents, they then claim that 70% of these accidents are avoidable by NOTAR (14.7%). Copter Cody, you are extremely gullable if you are relying on these "claims" to say they are statistics, these are "claims" made by the manufacturers, if you rely on every claim you are told, then you cannot say a sweeping statement that NOTARS are statistically safer!!

NOW COPTER CODY, IVE BEEN UP FRONT WITH YOU, TELL ME YOUR BACKGROUND AND YOUR EXPERIENCE! AND BY THE WAY, YOUR REMARK "YOU HAVE HEARD OF MCDONNEL DOUGLAS HAVNT YOU?" IS INSULTING TO ME AND OTHER PILOTS ON THIS SITE. i WAS FLYING HUGHES HELICOPTERS BEFORE THEY WERE BOUGHT OUT, MY GUESS IS BEFORE YOU WERE EVEN BORN, NOW TELL ME YOUR LICENCE TYPE AND EXPERIENCE, I AM VERY PATIENT.........


WAITING.........

[Copter Cody]

Sling Load,
I am not by any means trying to be insultive nor am i trying to knock on your experience. I'll bet you have more hours in a Helicopter than i have just looking at one. I did not mean to say MD, I meant to say the MD website. That was a typo. I am only working on ppl at the time, I've just started. I have under 10hrs. I just want it to been know that because i don't have as many hours or experience as you that doesn't mean i know nothing, nor do i know everything. why is it that whenever i post, it gets into i have more hours than you battle. I just wanted to know. And i did find out. Thank, Do you accept my appology?

Cody

[Thud_and_Blunder]

Cody,

A spot of advice, mate. You've 2 eyes and 2 ears, but only one mouth. If you make a conscious effort to speak only half as much as you listen and half as much as you observe, you may be half way toward learning a useful lesson about life, the universe and everything. The answer's 42 by the way, but you'd probably have to ask someone from the UK what that means.

Meanwhile, take it from me that your recent posts have done little more than show you to have:

A less-than-full command of English (presumably your 'first' language) Naievety of astonishing proportions An ability, conscious or otherwise, to wind-up professional-pilot readers and contributors to this forum

If you really have started flying lessons, and if they use radios where you're being taught, you may well soon learn about "think-pause-transmit". Please try and use the same lesson here on the BB.

Now, on the bright side and so as not to be totally negative, I'd just like to add that you obviously have considerable enthusiasm for what you do. If you can learn to channel that enthusiasm, harness it to work in your favour, then you may find that you can progress toward a thoroughly rewarding and enjoyable flying career.

Please don't feel you need to reply. In fact, a spot of silent observation and meditation from your corner of Oregon would be very welcome.

[Copter Cody]

...........................

[vaqueroaero]

Cody:

After quite possibly one of the best weekends I have ever had:

You say that you are not trying to be offensive etc, but then why did I have an email from you saying I am asshole?
Since we are now all be open and upfront, I only have 80 hours total time, but am still learning and, yes, one day I will have thousands of hours.
Take my advice: Stop being patronising. On the just helicopters website somebody asked for career advice. You replied with the great piece of advice: 'It depends what your personnal goals are. It is up to you mate'.
Nobody minds answering a question from somebody who is keen to learn. I consider myself very fortunate to be learning in an expert environment where the instructors have thousands of hours. These guys are professionals. They know what they are on about. I don't offer them advice. I keep quiet, listen, absorb and ask relevant questions when necessary. If you have a question then use the correct terminology (a helmet is a helmet, not a 'brain bucket')
Before anyone accuses me of being patronising, I have worked in different countries, doing many different jobs. You my friend are 17 and still living at home. Nothing wrong with that at all.
But please, don't call me an asshole, because I am not. And as I have said to you before the helicopter world is very small. Tread carefully.

[Copter Cody]

To all,

I think that i am going to do us all a favor. It seems that i do not fit in here, so i have decided to stop posting. I am sorry if i have affended any or caused any incoveniences. I do hope that you all accept my applogy.

forever sorry :(

Cody

Cody

[sling load]

Copter Cody,

Apology accepted, and i am glad to hear you are taking flying training and wish you well, your enthusiasm for helicopters is obvious, good luck to you.

You just should think about what youre typing, then say it out aloud before posting it!

Enjoy your flying training