Check Collective??

[rodrop]

Ok, I am getting so close to a ppl I can almost smell it (although that might just be me I smell).

Anyway, as close as I am, of course...a new CFI comes into the picture. Nice guy but definitely has a different way of teaching some of the techniques for flying (nothing big, just enough to stress me out because my last cfi did not do it that way ).

Anyway, here I am feeling good about my straight in autos and my new cfi has asked me to start checking the collective near the tail end of the 'ride'. Of course, it is only one little step that has thrown me aloop because I am not use to it...so I need to get over it and do it his way.

Anyway, i have read about checking the collective and have seen different comments about when to check collective...

prior to the start of the flare, tail end of the flare ?? or after the flare and then increase throttle and finish the power recovery.

any comments, thoughts that will help me get this right?

 

Also, is checking the collective just a part of the power recovery and if we are in a real live auto, would it help me to do it?

Thanks as always..and please know...once I get my ppl, I will share a piece of it with all of you.

[wopilot]

Absolutely check the collective. I have always done it just prior to flare as to not let RPM dip.

 

As far as having a new CFI, sometimes that helps as to get a different perspective on the same techniques, as you're already finding out.

[rodrop]

Thanks "wo"

from "ro"

 

thank you

[nikon858]

Absolutely check the collective. I have always done it just prior to flare as to not let RPM dip.

 

As far as having a new CFI, sometimes that helps as to get a different perspective on the same techniques, as you're already finding out.

 

 

OK not sure if you and the original poster are talking about the same thing....By you saying make sure the rpms don't dip, I think you mean check to make sure the rpm is in an acceptable location...I've always known 'checking' the collective as raising it an inch to keep the rpm under control......

 

And if the case is raising the collective an inch before the flare, absolutely not (at least on a private level)...once you enter the flare the cyclic should be the only means of controlling rotor rpm....The only time I can see you raising the collective a little before the flare is if both of you are heavy and a good load of fuel.

[helonorth]

I'm a little confused. What do you mean by checking the collective? To me, it meant adjusting it

right before the flair so as to not overspeed. If RPM is at the top of the green before the flair, raise the collective to at least get it in the middle. If RPM is in the middle of the green or lower,

leave the collective alone. Disclaimer: never flown a Robinson, so adjust as necessary!

Edited September 5, 2009 by helonorth

[BOATFIXERGUY]

I was thinking the same thing...never heard it that way before. Now "check rpm" yes.

[Mikemv]

To all, more bad internet info being posted to confuse pilots.

 

Best to all, MikeMV

Edited September 6, 2009 by Mikemv

[wopilot]

I'm a little confused. What do you mean by checking the collective? To me, it meant adjusting it

right before the flair so as to not overspeed. If RPM is at the top of the green before the flair, raise the collective to at least get it in the middle. If RPM is in the middle of the green or lower,

leave the collective alone. Disclaimer: never flown a Robinson, so adjust as necessary!

 

Yeah, always "chase" rpm's with your collective...

 

I was always heavy, and had to adjust adding collective just before flare, as you said. I just casually got used to doing it that way, thank you for correcting it for me.

 

In the B206, 50 ft start flare with cyclic then just before touch use collective to cushion.

[r22butters]

I have almost 600hrs., mostly in the R22, and I must say I've never heard of the term "check the collective". In a "power recovery" auto, I usually raise the collective slightly prior to entering the flare, to put the RPM at the bottom of the green, so it won't overspeed in the flare. However, if the RPM is allready low, raising the collective is not nessessary.

 

In a "real" auto, I would lower the collective prior to the flare, in order to preserve as much energy in the rotor as I can to cushion the set down. The main reason to raise the collective prior to the flare, is to prevent damage to the helicopter from an overspeed, but if the engine has failed, to Hell with the helicopter!

 

If you want to set up a pre-flare check, look at Safety Notice SN-38, it should be in the back of the POH. As far as having to change instructors, they did that to me, a lot, I always hated it. Getting different opinions/approaches on maneuvers can be good at some point, but not when I'm paying for it! If your new instructor wants you to do something you're not comfortable with, talk with him, he may be willing to do it your way, or at least try a comprimise.

[r22butters]

There is one comment I feel I have to make, in response to another post. The easiest way to use the collective in an auto, is to raise or lower it 'before' the RPM has a chance to move. In a flare or turn, it wants to go up, when you level out, or roll out, it wants to go down. Knowing this, move the collective accordingly 'before' you move the cyclic, thus 'anticipating' RPM movement. Using the collective in this way will keep the RPM more stable. You should never "chase" the RPM!

[RockyMountainPilot]

To all, more bad internet info being posted to confuse pilots.

 

From the onset of the autorotation(accomplishing the 3 aerodynamic transitions) to touchdown/power recovery, the collective controls rotor RPM. Although, rotor RPM will/may vary with cyclic changes, this is not the purpose of the cyclic control. Cyclic is used to control the attitude, flight path, radius of action, and during the flare a decrease in ground speed and rate of descent and ground contact attitude. Nikon858, 3 things happen in the flare and we should adjust the flare as required but not to control rotor RPM!!!!!!

 

I strongly disagree. You need to know how to use all the controls for a desired outcome. Using cyclic to keep or increase rotor RPM is something every pilot should know how to do. If you are alone in a helicopter, you might see the rotor RPM at 90% on the way down with the collective bottomed. Why not flare enough to bring it up to 110%? And if I have a full load and the RPM is at 110% during a real auto, I am flaring for whatever I can get. I don't care about a redline. I will flare to get as much as I can.

[Pohi]

I do not know about any other helicopter, but in the R22 and R44s that I normally do training in, I personally never touch the collective just before or in the flare.

 

I was taught, and I teach that the flare is a cyclic only maneuver. If the RPM changing wildly then the flare is not performed correctly. If the RPM drops, then not enough flare, if the RPM climbs, then too much flare.

 

But, there are a dozen ways to skin a cat.

[kodoz]

"Set it and forget it" is the mantra I was taught for managing the collective. If you're working the collective to manage RPMs, you're doing something wrong (most likely not managing attitude right).

 

Like others have said, I learned to check the RPMs one last time while entering the flare, but not to make a collective adjustment--only to determine the amount of cyclic flare I can use.

 

I've been working on a wikipedia-style web site for training procedures...the whole idea of it is that students can go there to see what other instructors are doing and what has helped other students. You can check out (and contribute to) the Straight in Autorotations Wiki by following [this link].

--c

[Mikemv]

I never stated that a pilot should not know how to use the flight controls, that is primary. I did mean that from entry to flare, the collective is used to control rotor RPM. Cyclic changes and disc tilting in a flare will change rotor RPM but RPM is still Controlled by the collective, NOT the cyclic.

Edited September 6, 2009 by Mikemv

[Mikemv]

Pohi, not using the collective as "DESIRED" in a flare is giving up one of the helicopters controls! It may not be necessary but should be used if beneficial. Think about the braking effect if the RPM is at the upper range prior to the flare. Knowing the RPM will increase in the flare, we can slow the rate of descent and ground speed with collective. This makes for very safe autos with a decrease in rate of descent and ground speed. I am not stating to use the collective during the flare of every auto but should be used when desireable.

Edited September 6, 2009 by Mikemv

[Mikemv]

"Set it and forget it" is the mantra I was taught for managing the collective. If you're working the collective to manage RPMs, you're doing something wrong (most likely not managing attitude right).

 

Like others have said, I learned to check the RPMs one last time while entering the flare, but not to make a collective adjustment--only to determine the amount of cyclic flare I can use.

 

I've been working on a wikipedia-style web site for training procedures...the whole idea of it is that students can go there to see what other instructors are doing and what has helped other students. You can check out (and contribute to) the Straight in Autorotations Wiki by following [this link].

--c

 

Chris, I know you are talking about R22 autos in a training situation. I agree that if you are chasing RPM with collective that you are doing something else wrong. However, as your career proceeds you will learn that flying other helos that a pilot learns to work/fly a rotor system for a real emergency maneuver. In my previous Bell 407, I could stretch the glide and decrease rate of descent in the auto by pulling the rotor RPM down to 90% and using min rate of descent or best glide airspeed. It was practiced so it could be a skill to use as desired.

 

Oh, and "Set it & Forget it" does not work in the real world emergency where maneuvering is required! What happens to rotor RPM in any turn, and maybe another to make the landing area? Fly the helicopter using the flight controls. The collective is not dead in an auto!

 

You guys need to think beyond the R22 Straight in for training. Imagine cruising at 125kts and then engine out, reducing speed to best glide or min rate of descent and maneuvering to LZ. Using collective is required to control rotor RPM, accept it.

[kodoz]

Chris, I know you are talking about R22 autos in a training situation. I agree that if you are chasing RPM with collective that you are doing something else wrong. However, as your career proceeds you will learn that flying other helos that a pilot learns to work/fly a rotor system for a real emergency maneuver. In my previous Bell 407, I could stretch the glide and decrease rate of descent in the auto by pulling the rotor RPM down to 90% and using min rate of descent or best glide airspeed. It was practiced so it could be a skill to use as desired.

 

Oh, and "Set it & Forget it" does not work in the real world emergency where maneuvering is required! What happens to rotor RPM in any turn, and maybe another to make the landing area? Fly the helicopter using the flight controls. The collective is not dead in an auto!

 

You guys need to think beyond the R22 Straight in for training. Imagine cruising at 125kts and then engine out, reducing speed to best glide or min rate of descent and maneuvering to LZ. Using collective is required to control rotor RPM, accept it.

 

Totally agree...we live in the world of training autos. Advanced autos need a place in flight training. My experience was that most of my instructors hadn't learned much beyond the basic auto, and weren't well prepared to teach max glide and minimum RoD techniques. I didn't know enough to ask, which is too bad, since learning these techniques helps you figure out what tools are at your disposal to manage RPMs.

[Pohi]

I am a big fan of using all of the controls during an autorotation.

 

If a pilot was to raise the collective prior or during the flare because they cannot properly perform the flare, what they end up doing is to cripple themselves during the very last part of the auto.

 

The amount of collective a pilot has left prior to the touchdown for the cushion to land, can be compared to an amount of reserve energy. If the pilot raises collective in a flare, then that pilot has just taken away some of the energy.

 

There are two ways I look at it.

 

1 Real auto: At that point, at the flare, who cares about the RPM. Short of throwing the blades across the field, the higher the better. The RPM at the red line is perfect, no damage to the helicopter and maximum kinetic energy for the landing.

 

2 Practice auto: Keep the RPM in or just above the green as much as possible. An overspeed makes for an uncomfortable afternoon with the boss. If the RPM is starting to climb, then all it takes is a pause on the cyclic for literally a second and then continue the cyclic flare.

 

If my students cannot do a proper autorotation( according to my humble opinion ), then they practice until they can.

 

There like I said, there are many ways to do a maneuver, I just prefer to do them according to the manufacturers maneuver guide and the rotorcraft flying handbook maneuver guide.

Edited September 5, 2009 by Pohi

[Mikemv]

Why learn/practice auto procedures and then during the "Real" thing throw out all of that experience? Is this not the time to be successful and fly the maneuver as we can with confidence?

 

To all of you up and coming students, pilots, CFI's, learn to be proficient and fly your aircraft with confidence. Do not throw all of that away in a panic of an emergency.

Edited September 6, 2009 by Mikemv

[Pohi]

I think you are confused as to what I am saying Mikemv. Of course, establishing a proper entry and glide are the key components to a successful autorotation. If a pilot can maintain proper pitch control after setting the proper RPM, then the RPM at the bottom of the glide will not be an issue.

 

I am only talking about the issue of adjusting the collective just prior to, or during the flare.

 

From the POH:

 

Many practice autorotations accidents occur when the helicopter descends below 100 feet AGL without all the proper conditions having been met. As the aircraft descends through 100 feet AGL, make an immediate power recovery unless all of the following coditions exsist:

 

1) Rotor RPM in middle of green arc

2) Airspeed stabilized between 60 and 70 KIAS

3) A normal rate of descent, usually less than 1500 ft/min

4) Turns (if any) completed

 

Here is a quote directly from the Rotorcraft flying manual:

 

At approximately 40 to 100 feet above the surface, or

at the altitude recommended by the manufacturer (position

3), begin the flare with aft cyclic control to reduce

forward airspeed and decrease the rate of descent.

Maintain heading with the antitorque pedals. Care must

be taken in the execution of the flare so that the cyclic

control is not moved rearward so abruptly as to cause

the helicopter to climb, nor should it be moved so

slowly as to not arrest the descent, which may allow

the helicopter to settle so rapidly that the tail rotor

strikes the ground. When forward motion decreases to

the desired groundspeed, which is usually the slowest

possible speed (position 4), move the cyclic control

forward to place the helicopter in the proper attitude

for landing.

 

And out of the R22 and R44 POH

 

7. At about 40 feet AGL, begin cyclic flare to reduce rate of descent and forward speed.

8. At about 8 feet AGL, apply forward cyclic to level ship and raise collective just before touchdown to cushion landing. Touch down in level attitude with nose straight ahead.

 

From the S76C++ POH

 

3. At about 50 to 75 feet, execute a flare to about 20 nose up by moving cyclic stick back with no change in collective pitch. Avoid excessive flare rate that can result in ballooning. When performed properly, the flare will check the rate of descent and reduce airspeed while causing an increase in rotor RPM.

4. As the flare looses effectiveness and the helicopter begins to settle, smoothly reduce the flare attitude to about 10 nose up.

5. Just prior to ground contact, increase collective to cushion the landing.

 

Now, correct me if I am wrong here, but i think it does say to use aft cyclic. Then it goes on to say that if the helicopter climbs, or the rate of descent is not arrested then the pilot is not doing the flare correctly.

 

These are the only POH that I have access to at this moment, so I can only speak for these ones. Others may be different, I am only talking about what I can prove.

 

And, to answer your question, no. I most certainly do not, and will not, practice an autorotation while overspeeding the rotor system. That's kind of like lighting your engine on fire to practice the emergency maneuver for a fire in flight.

 

I never said at any time that a student should ever overspeed the rotor system, so lets put that comment to bed. High in the band, is not overspeeding, it is only higher rpm and a bit more kinetic energy.

 

I certainly hope that a attorney or a court of law, and your pax, would applaud a pilot who has a strict adherence with the applicable POH, safety notices, and maneuver guides. Not sure, just my opinion.

 

However, I find that I am coming dangerously close to the statement "Arguing on the internet....."

Edited September 5, 2009 by Pohi

[Mikemv]

As you fly different models, with different pilots, either for Company positions/135 training or in Factory Pilot Transition courses, you will see that rotor systems fly differently, even from day to day with varying gross weights and DA's. Pilots do use all of the controls to fly and control the helo and during the autos, the collective controls the rotor RPM.

 

To All, fly safe, respect aircraft limitations and enjoy helo flying with an open mind to continued experiences and learning.

Edited September 6, 2009 by Mikemv

[NeverQuestionMe]

First time poster, long time reader. I have tried to stay out of the forum debates until now, but this one puts the panties in a bunch.

 

Lets try this situation on for size...

 

1. Grab an armpit full of collective before the flare.

>Distance to crash site increased

>Safe landing zone now at the six o'clock position

>RPM managable, AKA non issue, AKA rotor RPM at 80% (thank the gods there is a fudge zone... they won't stall. swear to those forementioned gods)

>Altitude increased. Afterall altitude is your friend. The more the better, especially during a hover auto

2. With the increased lift and altitude due to raising collective, additional time is now afforded to key the mike and scream "PAN PAN, OMG I'M GOING DOWN" and then, depending on the inertia of the rotor system, a quick prayer might be possible.

*Note* Since the rotors are now stalled, the passengers and pilot are now in a safe condition due to the lack of worry about the rotors coming through the cockpit

[nikon858]

Jesus, do you guys not realize were talking about how a STUDENT pilot should perform an auto??? Try and remember back to when you were first learning, there is no way you could manipulate cyclic/collective at the same time during a flare.......Again what I stated was for a private level, please remember this for the original poster and try and help him get through the maneuver.....like you guys have stated everyone has there own way of doing something...I have my own way, but I refuse to add any more fuel to the fire......just remember STUDENT pilot!!!

[Pohi]

Mikev

 

I enjoy a healthy debate from time to time. Yes, every autorotation is different in each helicopter, in each day, etc etc. Knowing how to fix a problem at the end is important, I like to have a person not be in the situation to have to fix an RPM problem at the flare. As long as the person gets to the ground and walks away, some people consider that a successful autorotation.

[NeverQuestionMe]

Jesus, do you guys not realize were talking about how a STUDENT pilot should perform an auto??? Try and remember back to when you were first learning, there is no way you could manipulate cyclic/collective at the same time during a flare.......Again what I stated was for a private level, please remember this for the original poster and try and help him get through the maneuver.....like you guys have stated everyone has there own way of doing something...I have my own way, but I refuse to add any more fuel to the fire......just remember STUDENT pilot!!!

 

Lets not be name dropping here, you can use my handle and I will be happy to respond.

xoxoxo.... now after thats handled, lets get down to business.

 

I sencerely hope I misunderstand you on this one. Are you saying that because a person is a student pilot, I should teach them to a lesser standard than a professional pilot? I believe that there should be the most care in teaching a student pilot how to do a maneuver correctly and perfectly the first time. This comes to the issue that some B.S. book called the Aviation Instructor Handbook calles primacy. All I can remember is blah blah blah, and then.....

 

Primacy, the state of being first, often creates a strong, almost unshakable impression and underlies the reason an instructor must teach correctly the first time and the student must learn correctly the first time.

 

So, what I get from this little publication is that any responsible instructor will teach their students the right way first and not give them a crutch because they are a "STUDENT pilot"

 

I prefer to keep my students alive, thankyouverymuch.