Restrictions with NOTAR system

[nouseforaname]

I'm looking into what helicopter to buy to keep on the N reg.

I've had a spin in a 500D the other day and was mighty impressed. I've been looking at the 520N...someone pointed out to me restrictions regarding NOTAR system, especially regarding wind.

What are the pro's and con's of the NOTAR system, all that occurs to me is that no1 will get cut up the tail rotor.

thanks v. much TD

[md 600 driver]

i have sent you a pm to contact me steve

[HELOFAN]

Interesting question ...please answer publicly..or PM me too !!
:O

[md 600 driver]

i ve sent you my details too steve

[Hughes500]

Horses for courses here

1. If you want low noise and a safe rear end but with limited tail rotor authority, added expense ( bigger engine and blades) and a complete nightmare to land if the donkey quits ( lack of yaw control ) have a 520

2. If you want fantastic tail rotor authority, faster cruise speed, less fuel burn, more range, less expense but noisy and less safe have a 500D

[mfriskel]

"complete nightmare to land if the donkey quits ( lack of yaw control )"

Can you expound on this?
Thanks

[md 600 driver]

mfriskel
he proberbly tried to hit the chains
steve

private joke.

[SilsoeSid]

"complete nightmare to land if the donkey quits ( lack of yaw control )"
Not strictly true is it Hughesey, as the Notar system is powered by the gearbox.

Perhaps you meant to say, "If the anti-torque system fails"
Like in most helicopters!!!

I wouldn't imagine any helicopter would get certified if, when the engine(s) fails, it 'fails safe!' to a yaw control failure condition!

:confused:
SS
(902)

[md 600 driver]

i have done lots of autos in the 520 and the 600 i also have done the factory training course on both the 520 and the 600 and also the 500

i can honestly say that they are not a complete nightmare to land if the donkey quits ( lack of yaw control ] in fact they are the opposite as they also have the added feature on all 520,s of YSAS [YAW SAS] on 600,s its an extra

in training you also do autos with the ysas switched off ,stuck pedal,anti torque failure

in the 900 ive only 1 engine out and in that if you didnt look at the instruments you may not even know one of the donkeys has stopped
steve

[SilsoeSid]

In addition, I think I am correct in saying that part of the air test schedule for rotorcraft is to have the ability, in autorotation, to yaw 30 degrees both left and right of track. (post yaw control maintenance)

Subject to written confirmation.

:8
SS

[SASless]

Either the 500D or E for the money would be a very good choice...providing you only want to carry one other person and some baggage. The rear seats are not passenger friendly except for legless midgets....with no baggage.

The advertised three in front is a joke....unless all three are skinny as Twiggy on a diet.

:E

[SilsoeSid]

The rear seats are not passenger friendly except for legless midgets....with no baggage.

Sounds like the ideal mode of transport for the present occupier of the 4th plinth at Trafalgar Square while she appears on every morning TV show around the country.

However, I think she comes with baggage.

I would post a picture, but feel it would go beyond public decency.
http://news.bbc.co.uk/2/hi/uk_news/england/london/4247000.stm
http://www.24hourmuseum.org.uk/nwh_gfx_en/ART30597.html


:yuk:
SS

[BigMike]

Yep, the 500D would be a nice private machine. If I had the money, one would be in my back yard... E model if you have longer legs. How close are your neighbours? The 520 might keep them happier.

[NickLappos]

I know of no NOTAR difficulties in autorotation, and honestly believe that handling on NOTAR is not a discriminator for the average user.

However, the NOTAR is actually misnamed. It HAS a tail rotor, but it is buried in the tail cone, powered by the main transmission. The Coanda effect is a small contributer to the tail control, mostly the tip nozzel is the controller.

NOTAR has more parts, more flight critical parts, more maintenance burden, less available performance and a poorer control envelope.

NOTAR has less noise, and is less likely to harm itself or others if the tail section touches something else.

NOTAR has failed to capture the market (the acid test of success) and its company has gone to the edge of bankrupcy twice.

NOTAR is more a testament to the power of the Discovery Channel than to engineering success. Those ancient, misleading shows (actually totally self-serving distortions) still run, don't they, otherwise we would be posting about gnat's asses or something more relevant!

[Hughes500]

Guys
I bow to your superior knowledge, last time I tested a guy on a 520 as we flared on the engine off landing the yaw control was pathetic compared to a normal tailrotor 500.
Not sure what the private joke is about - Steve

[DennisK]

Re 520 Notar Series.

As a Type TRE can I throw something into the pot.

Nick L's assessment covered all the relevant points nicely. The only downside I ever found was the reduced T/R authority in some configurations. Yes.... the final directional authority in a touch down auto.

Like Nick says. Notar is something of a misnomer. Really should be called the Movetar. (T/R moved INSIDE the t/boom)

With my heli sales hat on, there is always one acid test if you are concerned with its operational desirability and resale value. Just pick up the phone to a few specialist dealers and ask how much they'd pay for the model you may be buying.

That principle works for any helicopter. Nothing like backing judgement with your own cheque book !!

Dennis Kenyon

[diethelm]

The issue is not whether or not it works, the biggest problem with the 520 is parts. You can not get many critical parts for your fan and tail boom assembly. At least with a C, D, E or F model, there are plenty of PMA providers or at least enough spares around to find what you need most of the time.

Clank your tail boom on a 520, it does not matter that they cost 100k, you simply can not get one.

Until MD certifies another supplier or cuts a deal with KAMAN, and a few other critical suppliers, all of us MD operators are in for some down time.

I need a specific part of which KAMAN has 22 of them. However, you can not get one because of the $22 million dispute between MD and KAMAN. It is a $165 part........what a joke.

[md 600 driver]

andrew
it was a private joke to mfriskel who i flew with at mesa ringme sometime i will explain any way they were aidrians chains not mine
steve

[nouseforaname]

DennisK check you pm's