Prerotator

Stay with the original system. Proper engagement technique needs to be applied.

Use the rubber wheel as soft clutch to start the rotors and maintain engine rpm to +-2500 and slowly rotor rpm increases till fully engaged, now slowly increase throttle to recommended min rotor rpm.
You will be surprised to know. 185 to 250+ Rrpms makes no difference in take off distances.

I regularly prerotate to 200 Rrpms. 0 to 60kms in 4.5 sec. Nose up ritual with stick in the sweet spot while toe dancing till orgasmic autogyro flight is achived. Practise, practise and practise some more.

Good luck.
 
Hi Vance,

I am not confusing bad design and bad instruction

In france things are quite different then in the states

instruction is done on magnis elas autogyros that have powerfull prerotators

airfields have grass stripes in most cases, and a lot are short (300m 500m 900m)

so instructors can't teach how to charge a rotor from 80 rpm it is useless and dangerous for the machine

in addition as far as I can say watching American videos, take off style is really different, we pre rotate, we apply full power pushing the throtle quitely but up to full power, lift the three wheel in 0 to 30 m and then we stay at one meter and accelerate full power up to 110 KM/H before pulling to stick and ascending

when I watch american videos I see that American pilots I see accelerate more on the ground and then lift the wheels and go up straigth away .. I never go up under 110 km/h (I dod what I was taught)

in america you have this tradition of teaching how to charge the rotor from low rpm, not in France,

home builders pass their licence on magnis and then switch to their small birds

they just can't do what they did not learn in most cases and when they tried to do it they brake the gyros ... they are not badly taught they are not hahaha

this is the reason why it is better to install a powerful pre-rotator

when I did my crow hops, I prerotated up to 250 rpm and then accelerated quitely gainig speed until the front wheel lifted, I then reduced power and did it 5 times

the day after when the front wheel lifted I pushed the stick an flew one meter high above the stripe

I did it three times ... the fourth time I went into the pattern

we hate crow hops on short grass stripes ... it is dangerous for the machine

so in two day I was flying ...

I would have prefererd to be able to train on a long paved stripe and learn how to charge the rotor the old way ... but is was not possible

this is the reason why when I see newbies installinf electric rotator I always say ... make a "proper one"

I think I am rigth but in france

Please don’t imagine what you see in “American video” is how everyone here in the USA flies a gyroplane JM.

I fly different gyroplanes differently and different surfaces differently.

I do not pull the stick to ascend.

I fly Autogyro gyroplanes by the POH.

I do not fly like you describe in The Predator. She typically lifts the nose at around 180 rotor rpm and lifts off around 50kts in around 600 feet with no wind. Pattern speed is 60kts. I don’t open the throttle till I see 180 rotor rpm. She is often balancing on the mains as she accelerates from around 30kts till 50kts.

Here are some landings and takeoffs when The Predator still had the O-290 and I was a very low time pilot in San Carlos, California.
https://www.youtube.com/watch?v=RJH0F7HsK20

I often fly out of Oceano Airport (L52) which has a runway 709 meters with a 15 foot fence at the end and use about a third of the runway.

I also fly at El Mirage Dry Lake which is sometimes not smooth using a different technique (soft field).
 
Last edited:
airfields have grass stripes in most cases, and a lot are short (300m 500m 900m)

so instructors can't teach how to charge a rotor from 80 rpm it is useless and dangerous for the machine

I would have prefererd to be able to train on a long paved stripe and learn how to charge the rotor the old way ... but is was not possible

JM, what you describe as an "American" technique was often used in the past on unpaved runways shorter than 300m, in gyros with no prerotator at all. It required taxiing the length of the runway in one direction to "charge the rotor," then turning and taking off in the other direction.

It was certainly not the best thing for bolted aluminum frames with no suspension, but it allowed gyros light enough to qualify for our ultralight (115 kg) limit to operate.
 
It's all about training and learning rotor management. I've been flying gyros with electric pre-rotators for a long time and have never flapped a blade. Short fields, unimproved fields doesn't matter....I get my 27' rotors up to 100-120 rpm and slowly move the stick back while accelerating.......works everytime!!
 
Well,

you are right a couple of you tube videos can't help me to discover the American pilots style, it is just what I had noticed and it is probably not right

I did not want to criticize the style I had seen on those videos,

If I have the opportunity to learn how to charge the rotors by taxiing or by a smooth acceleration I will do it

but without any doubt it is really not a good idea to attempt to do it alone on a just finish home made machine when you have not been taught before

I'll ask my instructor how to avoid flapping the blade in those conditions

now that I have more experience then when I tested my bird the added task load will be acceptable

thanks for helping me to think about all of this

it is capital not to stick to an idea we have in mind ... I will reconsider it ...

there are many things that we think true but that are finally not so true ...

for example, last time I landed I taxied to the hangar and stopped at the stop point to fully stop the rotor ... I still had 40 rpm (I had landed just before the stripe in 4 meters in a strong wind)

looking at the hangar I saw my teacher making a sing to me asking me to put the stick in the direction on the wind ...

I was sure that with 40 rpm the rotors could not flap

my instructor put me in the M16 and put the gyro in the same position, we pre launched up to 80 rpm, and at 40 rpm he showed me how the rotor starts flapping when you don't put the stick in the wind direction ... of course we did not wait until the flapping becomes destructive

He had taught me long before to put the stick in the direction until the rotor was stopped ....but I don't know what I was sure that at 40 rpm there was no risk ...

I have to keep on learning

thx

You have a good instructor that is looking out for you JM.

In my experience the lower the rotor rpm the more likely the blades are to stall (flap).

On a very wind day sometimes managing the rotor as it slows is a challenge.

I make a point of letting the student manage the rotor as it slows if it is windy.

I feel an instructor in a two seat gyroplane with a powerful pre-rotator could transition the pilot under instruction to a less powerful pre-rotator by simply only pre-rotating to 100 rotor rpm and letting the student learn to get the rotor up to speed.

I do this with students even if they are going to fly something with a powerful pre-rotator so they can better understand how the rotor works.
 
You have a good instructor that is looking out for you JM.

In my experience the lower the rotor rpm the more likely the blades are to stall (flap).

On a very wind day sometimes managing the rotor as it slows is a challenge.

I make a point of letting the student manage the rotor as it slows if it is windy.

I feel an instructor in a two seat gyroplane with a powerful pre-rotator could transition the pilot under instruction to a less powerful pre-rotator by simply only pre-rotating to 100 rotor rpm and letting the student learn to get the rotor up to speed.

I do this with students even if they are going to fly something with a powerful pre-rotator so they can better understand how the rotor works.

Vance,

You are spot on in forcing the student to learn rotor management while you are providing dual instruction by limiting pre-rotation to 100 rpm.

That training would also be useful if and when their high speed pre-rotator decides not to function correctly.
 
Jean Claud, my problem is the belt don't hold the torque of that much hp without a lot of tension, if it has enough tension not to slip a little at full power the pump bearings wear quickly and the pump starts to leak , my next project is to get rid of the belt and go to a clutch with lock pins for full power operation.
Norm.
 
Having learned rotor management without a prerotator, the electrical assist prerotator obtained from Nicolas for the 23' Dragon Wings was quite sufficient to work well. I could not have managed the DW's without it.

Good training on all aspects of rotor management from the beginning is ESSENTIAL.
 
you guys sure like to wind up those blades up.I use a shaft drive and only use it get the blades going enough for the wind to spin them to rest of the way.
 
I think my engagement of the prerotator in the beginning was the issue. If I slowly engage at 2500 rpm and once the rotors catch up, I apply more pressure and slowly increase rpm. no vibration then. As far as not getting enough RPM, I go up to about 150 rpm and use forward speed for the rest. I also had a Bensen without a prerotator and had to use my hands as a prerotator so I'm familiar with blade whip etc. I think I got the problem solved. Thanks for all your input.
 
I can prerotate to around 230 RRPM with my dominator with the drive wheel, if it is a fresh wheel, but there is no need to I usually prerotate to about 150 and then get the blades up to speed on my takeoff run, I am still off the ground in around 500 ft. At Bensen Days when I have a 4000+ ft runway, I only prerotate to about 100 and just use more runway to get the blades up to speed.

Good practice for rotor management.
 
Glad you got the hang of it.

A Rattler will certainly rattle in the beginning. But all rattling is not bad.

Good luck and fly safe.
Regards
 
Top