another way to autorotate. with low ias, what do you think?

[warmkiter]

Hi

 

Just discovered on youtube this vid. its a german FTO teaching a new techique how to autorotate. its done with low ias and almost no flare in the end. the AOM of the Robinson say that in a low inertia rotorsystem most of the energy is stored in the A/C forward speed. this seems to work quite the opposite.

 

i would feel uncomfortable sitting and waiting when to start pulling the collective to reduce sinkrate, a flare from forward speed is much easier to access and adjust.

 

here ist the link http://www.youtube.com/watch?v=l-WwOMuIkt4

 

what do you think

 

cheers

[HELICOLT]

Wow very interesting... I would not have wanted to be the first one to try this lol, but looks like it works... Might be worth taking a look at

[Goldy]

Autorotation works by the air coming up from under the rotor and driving it. You don't need forward speed to do an auto, the Robbie course will show you that in the flying portion.

 

Notice however that they are in an R44, not an R22. The 44 has significantly more inertia and auto's like a dream compared to a 22. The management of energy is critical in this manuever, and you drive the rotor RPM so far down you risk a tail boom strike, especially if you carry a bit too much speed at the bottom.

 

So bottom line, more airspeed, keeping rotor rpm in the green gives you better control and is a safer manuever.

 

Neat video though, thanks for posting.

 

Goldy

[lelebebbel]

I have done this maneuver with a Robinson factory instructor. It works, but 3 things need to be emphasized:

 

1) there is almost no margin for error or adjustment. The timing has to be perfect.

And if you stuff it up, a power recovery will be hard or impossible to execute.

 

2) it will only work at LOW WEIGHT. My instructor said that if we had 4 people in the cabin or full fuel, we would break our backs. We did it at the end of a training flight, low fuel and with only two light weight people in the cabin.

 

 

3) this will absolutely NOT work in a R22. You will fall through like a bag of cement.

Maybe if you are solo, weigh 130lbs, and your tanks are empty, but I do not suggest to try this.

 

 

In other words, this is not some revolutionary new way to make autos easier - quite the contrary. It is just something that you can get away with if you have no room to flare, but only if you have a light helicopter with a lot of inertia.

Edited May 11, 2010 by lelebebbel

[ADRidge]

The first thing that comes to my mind is the story behind the "low g pushover prohibited" placard on the t-bar cyclic and the R-44 full of Germans saying "hey watch this".

 

Although with enough practice, in the right settings, it could be useful.

[Mikemv]

To All, first off, stick to your training and valid energy management in autos.

 

Video analysis shows this auto is set up in a DEMO environment from 1,100'agl. Initial airspeed is shown as 50kts, collective is lowered, attitude adjusted, only then is the throttle rolled off and the auto entered. At the Seminar at CHO this weekend, I talked about autos, aerodynamic transitions that are accomplished/or not and the goal of getting the rotor and rate of descent stabilized. The video VSI shows that the rate of descent is never stabilized, the rotor is in the low green with the horn ON and the rate of descent is increasing and little or no energy to transfer to the rotor.

 

The pilot performs the Practiced Training Scenario well but I recommend that no one think they will be successful with this technique trying it the first time in the real world with an engine failure!!!!!!

 

Thank you Goldy and Lele for good guidance/info in your post.

 

Everyone be Safe, rely on your actual experience and training,

 

Mike

[Eric Hunt]

We used to practice low speed autos (0-20kt) with the target neatly between your toes in the chin bubble, to touchdown in Hueys, but they have high inertia rotors.

 

We passed through the normal flare height, and when you thought "H01y ####!!" you pulled sharply on the collective, then cushioned on.

 

As stated above, it is a high judgment exercise, and you only get one go at it with no chance of a recovery - particularly in a turbine.

[Trans Lift]

I taught all these advanced autos in mainly 300's. No bi deal at all. The constant attitude one which the first post mentioned is used for enine failure in IMC or at night when descending into an unlit area. Works extremely well. The airspeed is held at approx 40-45 kts, and no less. No flare needed at the end.

 

For low speed autos (0-20kts), you must regain your airspeed for the flare.

 

I think all this stuff should be taught in detail on a commercial course. But unfortunately its not seen by many until you get to the robbie course, if you ever do that. For my JAA CPL we practiced all of these including; max range (higher speed, low RPM), range (higher speed, normal RPM), Constant att, low speed, Left pedal applied (90 degrees left of heading). It is necessary to know how changes in speed and RPM can affect distance in an auto.

[C of G]

My two cents:

 

Having done constant attitude touchdowns in several types I can add

 

1) It can most definitely be done in an R22

 

2) Timing, in my opinion is no harder than a conventional touch down auto

 

3) A go around is possible up until just about when you touch skids, same as any other autorotation

 

4) This auto seemed like the entrance was like most autorotation training in Robinsons, ie, lowering the collective prior to separating the needles. This seemed to be autorotation training, not a simulated engine failure.

 

5) Nearly all autorotation training is conducted in a DEMO Training situation and in actuality, an engine failure is likely to end in a less than perfect landing.

 

6) Do not attempt this, or any other autorotation without having an experienced instructor supervising. That can be said for nearly any maneuver in a helicopter you have not tried yet, or are not recently proficient in.

[Trans Lift]

Good points C of G.

 

I think where most people go wrong with the constant attitude auto is that they let the airspeed bleed off well below what it should be. Of course, you will lose the desired effect when this happens and a "collective" flare will not be as effective and you may settle through it. Therefore, this yanking on the collective technique.

 

I agree with CofG when he said that the timing is not much different than a standard flare. Gently raising the collective at the right height should give a nice cushioned run-on.

Edited May 12, 2010 by Trans Lift

[46yrsflyingF/W+R/W]

Used to do this in the UH1-H and a few other types. Common technique (at the time) for some Aussie groups. It works, but it is VERY unforgiving of "non-standard"-(Not in training) conditions.

It is very easy to get out of a safe "recoverable" Rotor RPM, rate of descent etc. Playing with it is a good way to splatter an aircraft. The old fashioned ARMY/Bell Rotor in the middle green, on airspeed, flare, Initial and then Cushion pitch pull technique(IMO)gives you the most flexibility and "options" when things start changing.

Training is one thing, when the engine really does quit is another. An aircraft in auto-rotation with the engine at Idle (needles well split) does NOT descend, maneuver or maintain Rotor RPM like one with the engine NOT RUNNING--the difference can be an "eye opener". Practicing (with an IP aboard)a good safe (and approved) technique is a good safety/currency and professional approach to flying. Unless your employers written job description (for your job) has something like R/D Experimental TEST PILOT on it why risk your ride, job and life "playing" to get that OH-so-cool "UN-Paid and UN-trained" Test Pilot tag on your gravestone? Remember in "Emergencies" training, the goal is to train for the unexpected, NOT the (Dumb Pilot)"INDUCED" Emergency.

Fly SAFE, and remember, that gravity stuff, NEVER QUITS--EVER...

[warmkiter]

this clip was found in a small german heliforum and is intended to promote a flightschool. Learning to operate an A/C means to know the limitations, and these are published in the POH . No need to try your self. These limititations are there to ensure a safe operation envelope for an average pilot and everyday ops. Offcourse you can push the limits and get closer to the point where there are close to zero safetymargins. I think this is a good example where the f*ckup-margin diminishes to none. I am sure this pilot has way above average handling skills, also demonstrated in a popular TV-show in germany where he is opening beerbottles with a opener attached to the skid of a R22. Exposing yourself to a higher risk and a lot of publicity can be fatal.

 

good luck