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-   -   Notar helicopters and autorotation? (https://www.pprune.org/rotorheads/400357-notar-helicopters-autorotation.html)

SkyyL4 30th December 2009 17:17

Here is how NOT to do it :eek:



Bertie Thruster 30th December 2009 17:33


Well it's a little clearer, but I still do not understand why you should not autorotate after a fan failure and why you can not auto rotate unless you have a double engine failure?
2 questions there i think. unless you are having me on!

1) 'conventional' autorotation does not work for a notar failure.

2) after a notar failure, if both engines happened to fail (for whatever reason) then not entering autorotation would be rather final!

RVDT 30th December 2009 18:15

It's the softer option. Power on run-on landing at **knots?

Not possible without at least one engine of course.

The auto without the fan has probably never been proven nor does it have to be. The power on option can probably be demonstrated with a "zero anti-torque" setting.

Read this download about a 900 in Japan.

Stan Switek 30th December 2009 20:55

Good example here:


Ian Corrigible 30th December 2009 21:00


Originally Posted by SkyyL4
Here is how NOT to do it

The unfortunate irony here being that this training flight, flown with a factory pilot on board, was actually being filmed by other CBP pilots who had concerns over the 600N's autorotational characteristics (esp. in light of the loss of an aircraft during a post-IFSD auto in Februrary) and who were hoping to have their fears assuaged.

This fleet, the largest NOTAR fleet in the U.S. and the second largest worldwide, has now reportedly been grounded due to safety concerns.

I/C

SkyyL4 30th December 2009 23:50

Ian,

It looks to me like this accident was pilot error and had nothing to do with the aircraft capabilities.

Sulley 31st December 2009 12:18

Shawn -upon initial auto entry (902) the rotor rpm is or can be a little feisty to begin with.So what happens often is that the 'auto' is now effectively a low power descent not a true auto (15-20% torque) under these conditions turning right can be interesting. :ooh:

DeltaNg 31st December 2009 16:38

Seems like a NOTAR is a lot of extra hassle for a dummy-proof helicopter.

HueyLoach 2nd January 2010 19:05


My spies tell me that while there is no problem with controlling yaw in autorotation, in the part between powered level flight and autorotation, i.e. a low power descent, yaw control is less than sparkling - some even report difficulty in turning right. Anyone confirm this?
Yes, yaw control is not as good as a conventional helicopter but once you get used to it (some tap dancing), is not a major issue. Difficulties doing right turns? I don't think so, if you maintain some airspeed and aircraft in trim. I am talking about the 600N. I don't know the 520 or 900.

HueyLoach 2nd January 2010 19:19


It looks to me like this accident was pilot error and had nothing to do with the aircraft capabilities.
It may have something to do with it; I don't know. In addition the 600N has one the highest disc loading figures in its weight class. What it means is that unless the pilot executes an almost flawless autorotation from entry to touchdown, his/her chances of not damaging the aircraft are slim. Very little margin for error in my opinion.

rotorfossil 3rd January 2010 09:54

Delta ng. I agree. When the 520 first came out, it was possible to compare it directly with the 500E. The 520 was slower, used more fuel and lifted less. I agree it was quieter, you could back it into a tree and idiots couldn't walk into the tail rotor. Didn't seem a particularly good deal overall.

DeltaNg 3rd January 2010 11:08

lol...

Lots of people go on about the backing it into a tree or whatever - does that mean it is like a dodgem car so that it just bounces off whatever it hits and you just carry on ? :}

Surely the next step is to get rid of the pesky rotor blades too, they can catch on things as well. NOTAR/NOBLA is the future......:ok:

Bertie Thruster 3rd January 2010 12:10

Why are you fretting so much about the 902, Craig?

Are you thinking of moving across the road?

DeltaNg 3rd January 2010 12:55

Thought about it, but no. I need to get really good at surfing - and quick ! :ok:

jim63 22nd March 2010 02:01

A run on landing??
 
Seems alittle fast for practice autos.
Police Helicopter Pilot - Police Helicopter Journal - Video Of Border Patrol MD600 Helicopter Auto-HardLanding.

Nigel Osborn 22nd March 2010 02:53

I'm sorry but from that video that simply looks like a bad auto. I'm quite sure FAA would have certified the 500 for autos, so unless there was a mechanical problem, what is left other than human error which unfortunately can happen to anyone.:confused:

Trans Lift 22nd March 2010 03:04

Looks like a crap auto to me too. Tried to flare but it was way too late...

mfriskel 22nd March 2010 05:52

I believe there were several successful autos prior to that one.

SilsoeSid 22nd March 2010 08:24

I love the comment;


Also, as I stated in the original post, I have personally received emergency procedures training from the same CFI on several occassions and can attest to his professionalism, outstanding skill level, and expert knowledge of all things helicopters. You be the judge.
:ugh:

psst...no-one mention Dennis!:E

Hell Man 22nd March 2010 09:22

Yes there was a Brit who's last name rhymed with the Grand Canyon who suffered a similar problem of fast approaching ground :ooh: in an HU269!

Perhaps lite helos should be fitted with a basic rad alt!


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