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How to improve autorotation?


alexc
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I have been practicing straight-in auto (in R22) many many times, but my entry is not ideal. I want to get better before my check ride.

 

My CFI taught me to use the "down, right, aft, roll, pitch check" sequence for the entry. I personally do not feel fully comfortable to do the mechanical procedures. So, it is on and off and no further improvement. During the entry, my mind is blank except the procedure sequence, also I feel loss of gravity, which "scares" me for a second. It's like driving a car over a unexpected ditch.The main obstacle is that I feel that this mechanical process is not fully under my control (definitely not good for heli flying).

 

I figured out that I do better if I rely more on my intuition/feeling/anticipations.Then I can have more control over the whole process. When I do hover-auto, I just anticipate, feel, act accordingly after roll off, it seems like it is working well. I applied this method to straight-in auto once, not very good, my entry got slightly worse, feels like re-learning, so I plan to try a few more times during the next few flights. I know everyone learns differently, but it is still good if the Gurus here can give me some suggestions.

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Couch flying is an underrated technique. It helps you pre-visualize what will happen in the air so that you know what to expect. Remember that practicing autos is different than the real deal. In practice, you can enter gently instead of a collective drop. We would practice a cadence that when said aloud would mimic your actions. The gentler the entry, the less that initial entry will feel like a drop in your stomach.

 

Second, make sure you know exactly WHY you have to perform each motion. Break down each step and analyze it. How come we need right pedal? Why does the nose drop? Etc. Knowing this helped me slow down time in the air.

 

In the air, start back at the basics. Take it up to a higher altitude and only practice entries. We would go 3000 AGL, enter, recover, enter, recover, etc. It helps take away the ground rush anxiety. I wouldn't take a student on airport until they nailed the entries and were comfortable in the glide portion reacting to different scenarios (how to get back a/s, rpm, etc.)

 

Lastly, ask your instructor to perform a 2 or 3 autos so you can sit back and observe. You can learn a lot just by feel and by sight.

 

Hope that helps.

 

EDIT: This is by no means wrong, but one thing about the "aft" portion of your sequence. I teach students to maintain current attitude. Keeping it level will require some aft cyclic, but how much? A student may develop muscle memory just for the sake of the sequence without really determining the correct amount of aft cyclic. Just my two cents and I'm certainly not advocating that this is the only way to teach.

Edited by dagrouch
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I always think and say "down collective, right pedal, aft cyclic to 70 knots, off throttle." once that's done, I'm prepared to bump the collective up a tad to prevent the rrpms from climbing. I think part of it may be that you're slamming that collective. Depending on whether you're flying the 22 or 44, you can get away with a smoother down-collective motion. Try to be a little smoother on the controls and realize it's all pretty much one movement to enter, and only then do you roll off the throttle.

 

My experience is that to make it fluid, you need practice. How long have you been doing straight in autos?

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Are you getting unannounced throttle chops from your instructor ? Or are you entering autos on your own ? I can tell you some gamesmanship depending on how you are initiating them. In no way would I try to contradict anything your instructor would say, just some technique type items.

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I would just add, start your autos in that perfect scenario. 65 or 70 knots airspeed, level attitude, low power setting (maybe 20").

 

Then lowering collective isnt such a big deal, your airspeed is already set so maybe only the slightest aft movements required. Start easy and go from there. Drop that collective all the way down and start pulling it back in to maintain rpm.....it will build quite fast on you.

 

No reason to do throttle chops here, no reason to make aggressive control inputs. Just down and smooth.

 

Good Luck,

 

Goldy

Edited by Goldy
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Sounds like your instructor might not have prepared you for what to expect...so you'll have some fear to overcome and incorrect muscle training to fix.

 

First recommendation would be to slow everything down for practice autorotations. The purpose of this maneuver is to practice autorotations, not to recover from a sudden engine failure (where you might have been told you have 2 seconds until terrible things happen). Lower the collective oh so slowly. Relax, look at your attitude and make the input to fix it. Roll off the throttle (or better yet, have your CFI do it for you initially). Now start your scan...attitude, attitude, RPMs, airspeed. Slowing the maneuver down is acceptable for learning it. (This goes for hover autos as well.)

 

Lots of other very good advice: armchair flying the maneuver, visualizing why you need to make the inputs you are making, starting up high and focusing on just the entry and glide.

 

How is your overall aircraft control? Can you enter at 700 AGL and 70 knots almost every time, or are you struggling to maintain an altitude and airspeed?

 

And stick to 2-3 practice autos per flight initially.

 

Good luck...come back and let us know what helps/doesn't.

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The number one priority is to get the ship level after lowering the collective. Attitude (of the aircraft) is most important. Get that right and everything else will fall into place.

 

The most common mistake I see is people focusing too much on a certain mechanical control sequence, and not enough on what the helicopter is actually doing.

Look straight ahead at the horizon when you lower the collective, and move the cyclic and pedals so the helicopter stays level while you do it. Just like you would if you were just initiating a normal descent, except a little quicker.

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AlexC, It sounds like to me, from your post and description of your autos, that you are not setting yourself for the proper entry... Sounds like you are already behind the power ball when you drop the collective, and you find yourself doing all kinds of corrections on the way down. And in an R22, you definitely need to be precise with your control inputs and the proper entry setup to the auto.

 

On your down wind leg you should be at 70 knots, 800 AGL before entering base... On final there should be little to no correction before you lower the collective. In other words, you should be setup and relaxed. Smoothly lower the collective, right pedal input, aft cyclic maintaining 60 to 70 knots speed; no more than 1500 fpm descent rate, rotor rpm needle in the green!!!!

 

Your CFI should of been yelling those numbers to you constantly when you were learning your piloting skills. "1500 FPM, 60-70 knots ASI, rotor RPM in the green!"

 

Forget the the intuitions and anticipations! This will get you in more trouble than anything else. Do it by "the book and by the number!" It's more fun and less stressful on you! RP

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I agree, looking outside is very important to keeping things smooth. As far as how fast to lower collective, I verbalize with students a slow count, "one thousand one" and the collective should be all the way down. Maybe not perfect, but that's the pace I use.

 

When students have problems with the entry, I practice that portion a few times. Basically, entry, stabilize and recover. Then do it again, each time only loosing a few hundred feet.

 

Another technique I sometimes use is to take the sometimes scary "auto" word out of the equation. What I mean by this is to fly straight and level, and have the student initiate a coordinated collective descent, maintaining pitch, trim, and airspeed. Then level out. Then basically have them do it again, each time increasing how quickly they are lowering the collective. What this typically does is to gradually get the student used to maintaining attitude, airspeed and trim. After only a few times, they usually are able to lower the collective at the pace of an auto and maintain the aircraft, and then the only thing that is left to make a quick collective descent into an auto is to roll the throttle off.

 

I'm sure what I wrote probably makes no sense, but it seems to work. The whole goal is to make the student comfortable. I'm sure you can all relate to a student flying along, or hovering perfectly until the word "auto" comes out, then they are all over the place. My goal is to get them as relaxed and stress free in an auto as they are in an steep approach, and hopefully at some point even enjoy autos.

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Dagrouch, I totally agree teaching is very underrated. You are right on the "aft" part! I developed a muscle memory just for the sake of the sequence. I didn't know it doesn't work on me until hundreds of times of practices (probably close to 200 times) and still doesn't work consistently. So, I have to figure out something different.

 

I actually also have the same idea: I will ask my CFI to do autos, I will just sit back and watch next time. Gentle and smooth entry has been always my goal, but I just couldn't do it. Now I figured out that I focused too much on mechanical control sequence rather than what the heli is actually doing, exactly like what lelebebbel said. Pohi, I also like your idea about practice from normal descent to auto gradually. It is something that I have been thinking about to try (i.e. channel my skills from normal descend to autos). It's funny that I have a very strong quantitative background, but focusing on numbers or mechanical sequences do not work on me when I learn heli. I also appreciate all other Guru's inputs .

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I got another question about auto flare in R22: is it fine to let RPM increase a little bit during flare?

 

My CFI probably adds a little bit too much collective during flare, which often triggers low RPM warning light at the end of the flare if the throttle is not rolled on quick enough. I roughly remembered other CFIs never mentioned pitch check during flare. My memory could be wrong though, so I want to double check it here.

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I got another question about auto flare in R22: is it fine to let RPM increase a little bit during flare?

 

It all depends on where the RPM is when the flare starts. If it's already high, then absolutely not. I'd caution again against an automated input. As you begin to flare, a check of the RPM's is crucial. If you're getting the low RPM horn/light when power recovering during training, that's asking for trouble. The other side of the coin though is paranoia against overspeeds, but that's something you shouldn't be concerned with as a student. Your CFI is responsible to guard against that.

 

Bottom line in a real emergency, you lower collective during flare to get the RPM's as high as you can to have enough energy to cushion that landing. It does you no good if you have an armful of collective as you cushion. My opinion is I'd rather risk an overspeed than get a horn/light because low RPM means you'll split skids, bend the tail cone and worse.

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I got another question about auto flare in R22: is it fine to let RPM increase a little bit during flare?

 

My CFI probably adds a little bit too much collective during flare, which often triggers low RPM warning light at the end of the flare if the throttle is not rolled on quick enough. I roughly remembered other CFIs never mentioned pitch check during flare. My memory could be wrong though, so I want to double check it here.

 

Yes, you want the RPMs to increase during the flare (and a horn at the end of a power recovery isn't a good thing). There are a few things going on here that have to do with how to teach autos and do *practice* autorotations, but Robinson's recommendation is to terminate an auto that isn't going well (for example, with RPMs too high or low). At the end of the day, it's your CFI's responsibility to guard against all the bad things that can happen.

 

One thing that I picked up along the way was to set and hold the engine RPMs at the bottom of the green as you enter the flare. This reduces your workload as you initiate the power recovery--the governor and correlator will join the needles at the termination of the maneuver. Then again, throttle work might be best left to your CFI.

 

Given where you are in your training, maybe working on the power recovery isn't where you need to be... To do a good power recovery, you have to have a good glide; to have a good glide, you have to have a good entry.

 

My uninformed opinions only. I hate second guessing somebody else.

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Looks to me you may need to go fly with a couple other instructors to gain some different perspectives. If you do, something may “click” which gets you to understand the autorotation is just another maneuver like all the rest of them. That is, it’s no biggie. Furthermore, along with the go to altitude and play with the RPM suggestion, have an instructor demo a full down. This way, you can get a better idea of the “big picture” of what you’re trying to accomplish and why…

 

Remember, a good autorotation to a bad spot is always better than a bad autorotation to a good spot…

Edited by Spike
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I can honestly say that nothing in my life scared me more than doing autorotations in the R22. The low inertia rotor system just "dumps" the energy so fast. When I was doing 180 autos, I felt like we were a missile pointed straight at the ground. I can say that as I continued in my training, I became more and more comfortable with the manuever. When I was early in my training, I would essentially stare at the gauges trying to hit the "numbers" and felt oblivious to the outside as the ground approached RAPIDLY. When I got to CFI training, I had a different instructor than before and he was a real veteran at teaching/flying and that experience began to change everything for me.

I would suggest that you 1. Understand that you will get better with experience, 2. Learn to "slow" the process down, and 3. Fly with a veteran instructor sometime(s) for a different experience.

Hang in there, it will come, have fun, and fly safe. Down the line, if you get the chance to do autos in the R44, you will be amazed at the difference( they almost don't want to come down, because of the energy in the rotor sysyem)

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It's been awhile since I've done autos, but I'll walk you through what I was taught. I have a different flow than you were taught, so you can apply it as you see fit. This is for you entering the auto, not throttle chops.

 

If you're getting nervous before, take a few deep breaths before counting down, calm yourself down.

 

I count down 3, 2, 1

Down, off, right, level (the ship)(it's all fluid, almost simultainously)

Trap it (the rpms)

outside

rotors, airspeed, trim, outside

rotors, airspeed, trim, outside

keep doing this until it's time to flare.

 

Are you doing your training at altitude?

I agree with Spike about flying with other instructors. I had a very experienced instructor for private, and he was great. But my pick-ups and setdowns sucked. Nothing he said clicked with me. I went and flew with the Chief Pilot, and he explained it slightly different, and it clicked!

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since you are feeling frustrated you may want to ask to try them with one or two other instructors I found it helpful to see them from other people. everyone does them the same but everyone has a slightly different way of approaching them with a student which is nice.

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Update: I practiced a few more entries. I started with normal descend and gradually transitioned to auto. I focused more on the helicopter's reaction during this exercise. I realized that the needed "aft" cyclic movement is actually much smaller than what I expected. Once I slowed down the process, I didn't feel my stomach drop anymore. I also sat aside to observe my CFI entering the auto, which helped too.

 

I knew my problem was too much aft input (over-action) after I felt my stomach drop when I lowered the collective too quickly. I don't like the mechanical entry sequence, but it is not that easy to completely get rid of it right away either. It would also take me some time to re-learn a new method. So, to fix my problem, I modified the entry sequence to "down, right, SMALL aft, roll off, pitch check". I added "SMALL aft" to remind myself small inputs, then it worked.

 

After those exercises, I learned more concrete ideas about autos. I still use the mechanical sequence as a helper, but I rely on it less and less. So far so good.

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I had the hardest time learning 180 autos. I just couldn't get all the pieces to come together. I'd absolutely nail one, except I would let the rotor RPM climb too high, or forget my callouts, etc. It wasn't until the checkride that I actually figured them out LoL! Sometimes it just takes a little extra time.

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