First auto rotation + setup

[o0dekker0o]

I looking into doing a auto rotation on my trex 550. How do i set up my throttle curve.

Should the curve be the same as my idle up 0,25,50,75,100 full -10 / +10.

How should i set up my throttle curve, flat 0,0,0,0,0 ?

[Bob O]

The auto rotation is done in Throttle Hold, so you would leave your regular throttle curves untouched.

Pitch curve can/ should be linear. Here's an excellent video if you haven't seen it.

Curtis Youngblood autorotation class (27 min 8 sec)

[o0dekker0o]

Nice, thanks

[ArchmageAU]

Originally Posted by o0dekker0o

I looking into doing a auto rotation on my trex 550. How do i set up my throttle curve.

This question speaks danger to me. (Like asking for the correct fitting instructions for a parachute. Good question, but hints at a lack of other important knowledge.)

To answer the direct question. The TH curve should be 0,0,0,0,0. The TH pitch curve is a matter for debate, I use 0,25,50,75,100 to match my IU pitch curve, but others sometime use ones with less aggressive negative pitch. HOWEVER, when learning autos, your TH may be set higher than 0 depending on the technique you use to learn.

Learning autorotation is stressful. You really need to KNOW what you are doing as YOUR $1000+ bird is literally falling from the sky. (You fix if you stuff up. May become the last flight of the day).

I would encourage you to study all you can find on autorotations, how they work, techniques for practice, how to creep up on them gradually, etc... There is tons on information on HF and on the net on how to learn autos. Just flying on correct curves and hitting TH and hoping you can get it right before pancake is not an advised method of learning.

Start of the sim, get them right there, then GRADUALLY re-learn them IRL. I can auto a 600 into a 5x5m area from 90m in the sim (Heli-X) 19 times out of 20, but have not yet tried with my X5. I intend to re-learn IRL by working first on powered descents and flairs, then under-powered descents and flairs (non-zero TH - as hinted at earlier), then finally fully autos (zero TH).

If possible, get real life training from others who can auto well. One thing to know it, another to experience it.

The advice posted by previous responders is good. Please heed that too.

I just do not want you to take unnecessary risks with your "perfectly good" trex 550 due to lack on information.

[Bob O]

I really like this video:

450 Pro Auto Video (4 min 57 sec)

[RogerRabit]

Autos are fun

I did hate them til beginning of the year or end of the last arround and then had a lot of trouble with a tailgear resulting in a lot of ( suprisingly successful - but might be due to the snow ) autos.

Then i decided to train them correctly like i was tought long, long ago in a flight school

Now i do some each flight, sometimes i do 10 or 12 minutes just autos, but it is little heavy on the cluchliners.

You go up, away from you and then fly a fast descending 45 degree landing ( not nose dive but flat disk type )
You do this several times and you will hear the disk rev up in the descending, showing you that you actually do not need but get power from the descend

The only difference now is that you switch off power.

There is absolute no difference.

The chopper does not fall nor do you have to steer the sticks different.
Fast flat descend, land, period.

I do not think that bail outs and such are helpul.

If you do not trust your heli, you can set a low rpm to the TH switch.

that has two disadvantages.

First - it does not really help if you do not know how much to lower the rpm and from a certain point the heli gets instable

Second - If something wents wrong the damage is minimal when the drivetrain is without power. I just had 2 crashes on my 500 over grass ( higher ) without real damages to the chopper ( a skid and a flybar rod )

If the drivetrain has a minimal rpm the typical damage is totally different.

[willr001]

It's a good time, just did my first one (and then five or six more) on my Fusion 50 this weekend. Firsts are awesome, haven't had one in a while. Assuming you run a linear pitch curve in TH already, you shouldn't have to change anything. Just do it.

My problem was hitting the TH while way up in the air. Couldn't bring myself to do it. This weekend was showing a few family members at our reunion the Fusion 50 in an adjacent field, was flying around and someone said, "It can't autorotate though, can it?" Well, damn if I'll let that slide with a simple "Yes, it can." Do a climbing circle till it's zipping around at altitude, and boom, hit TH. Aim was off, so it ended up a ways away, but came down gentle and easy enough. Even got some applause for the piloting skills for the first time ever. I can't even do funnels, so I won't let it go to my head.

So, if you can do them in the sim, and you're the type of idiot that likes trying to impress others, get some spectators around to cajole you into doing your first one. Worked for me!

[ArchmageAU]

Originally Posted by willr001

It's a good time, just did my first one (and then five or six more) on my Fusion 50 this weekend. Firsts are awesome, haven't had one in a while. Assuming you run a linear pitch curve in TH already, you shouldn't have to change anything. Just do it.

Congratulations.

Originally Posted by willr001

So, if you can do them in the sim, and you're the type of idiot that likes trying to impress others, get some spectators around to cajole you into doing your first one. Worked for me!

This would probably cause my first blade-stop catastrophe.

I can imagine explaining ..... "No, the heli is stable. Those plummeting wet-dog shakes was me. Now, if you will kindly excuse me I have some blades and shorts to change. "

[Steve Graham]

The Curtis Youngblood video as well as this one by Bobby Watts http://www.smacktalkrc.com/archives/568 are pretty much all you need to know about doing autos. The FAA's Helicopter Flying Handbook available for free here http://www.faa.gov/regulations_polic...ying_handbook/ has some very good information on the physics of autorotations that would be of great value as well. One thing we don't have to worry about that the full scale guys do is over-speeding the head. This allows us to actively seek to gain as much head-speed, a type of kinetic energy, as we can without fear of blowing the machine apart.

It took me a LONG time to finally start doing autos after re-kitting my 700 trying them without the skills or knowledge to really understand what was happening.

IMO you need at a minimum the following:

1) An academic understanding of the maneuver. This maneuver requires what I have started calling "energy management". This involves an understanding of how your machine contains both kinetic and potential energy and how the use of collective as well as cyclic inputs affects the equation. One of the biggest mistakes I make as well as others I watch is the use of collective during the flare. A heli in a steady state autorotation needs little to NO collective input to both level off from the descent and stop it's forward motion. Adding collective during the initial phase of the flare wastes kinetic energy and may even cause the heli to climb making the final phase of the landing more challenging than it should be.

2) A proficiency level on the sticks that allows you to achieve the relatively subtle inputs required for autorotations.

3) Enough confidence in your flying so you don't "forget" how to fly, like I did , the second you hit TH.