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skeptic36

Sport Pilot Drifter story

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Hi all,

 

I read the story today by Rob Knight on his experience flying the drifter.

 

I don't understand why, because the propeller is close to the rudder more of the slipstream strikes the right side of the fin than the left thus making it more responsive turning right than left.

 

Can anyone enlighten me?

 

Are the motors offset to counter torque?

 

Regards Bill

 

 

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Drifter Pilots will notice a few errors in this feature, still its good to see some one taking an interest in the good old Drifter

 

 

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Every Drifter is different! I've flown... hmm half a dozen different Drifters and they all behave slightly different.

 

They all kick right if you into the power on take off without any rudder correction!

 

 

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Would the Drifter be a good aircraft to learn to fly if you wanted to learn to fly a Sapphire. I"ve been told and had already gathered learning a bit of glider flying would be good idea.

 

 

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l have never flown a sapphire so l dont know the differences but a Drifter is a great aircraft to learn to fly in.

 

 

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Would the Drifter be a good aircraft to learn to fly if you wanted to learn to fly a Sapphire. I"ve been told and had already gathered learning a bit of glider flying would be good idea.

Yes mate, If you want to fly a Sapphire, the Drifter is the nearest dual seat trainer to the Sapphire, however, the Sapphire will be more twitchy on the elevator response due to the flying tail. I am told the Sapphire is an inspired aircraft and great fun to fly.

 

 

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Hi all,I read the story today by Rob Knight on his experience flying the drifter.

 

I don't understand why, because the propeller is close to the rudder more of the slipstream strikes the right side of the fin than the left thus making it more responsive turning right than left.

 

Can anyone enlighten me?

 

Are the motors offset to counter torque?

 

Regards Bill

I don't know about the drifter but the cork screw effect of the prop slipstream will do what Rob says.

 

 

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The engine is also mounted pointing thrust line a little left as well.

 

 

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I learned to fly in a lightwing, and then stepped straight into the Sapphire with no problems at all. Yes, the elevator is sensitive. You do use up alot of ground when landing until you get used to it. . 010_chuffed.gif.c2575b31dcd1e7cce10574d86ccb2d9d.gif 010_chuffed.gif.c2575b31dcd1e7cce10574d86ccb2d9d.gif

 

 

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Havn`t read the article but anyone who knows their theory will know that a right hand rotating prop on a front mounted engine, is furthur away from the verticle fin and rudder than the rear mounted engine on the Drifter,therefore, the slipstream will rotate around the aircraft and strike the verticle fin and rudder on the left hand side,causing the aircraft to yaw/swing to the left, on applying power on take-off.

 

Due to the engine on the Drifter being so close to the verticle fin and rudder, most if not all of the spiral of the slipstream will strike the fin on the right hand side and the AC will yaw/swing to the right as power is applied....Yaw is not corrected, simply by applying left rudder...Both feet have to work in coordination to keep the AC going in a straight line.

 

I don`t find any difference between a left or a right hand turn in the Drifter, it`s the method applied that will cause a difference, however, in a power on stall in a level turn to the left, ( nose level with the horizon ) , the high or right wing has a greater angle of attack and stalls first, causing the wing to drop.....If the stick is held back and in the central position, the AC will roll back to level.

 

In a power on stall in a right hand turn,( nose level with the horizon ), if the AC is held in the stall, it will tend to roll into the turn,due to the slipstream striking the right hand side of the verticle fin.

 

Frank.

 

Ps, I`m not suggesting anyone go out and try stalls in the turn, I`m simply pointing out what happens in the Drifter.

 

 

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....... Ps, I`m not suggesting anyone go out and try stalls in the turn, I`m simply pointing out what happens in the Drifter.

Why not Frank; that is exactly what a Drifter pilot should do, and do regularly to keep them sharp as long as it is done initially at a good height if you are not confident, say 3000' agl minimum. Alternatively if they are not comfortable, then do it with an instructor. Frankly if they are not comfortable with a such a maneuver they should do it with an instructor for their own safety sake. I am a great advocate of this type of practice.

 

 

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Why not Frank; that is exactly what a Drifter pilot should do, and do regularly to keep them sharp as long as it is done initially at a good height if you are not confident, say 3000' agl minimum. Alternatively if they are not comfortable, then do it with an instructor. Frankly if they are not comfortable with a such a maneuver they should do it with an instructor for their own safety sake. I am a great advocate of this type of practice.

 

Thank you David, You are absolutely correct, I couldn`t agree more, but in this " Duty of care, always someone elses fault ", mentality society we`ve become, I`m hesitant to recomend that anyone do anything.

 

It`s a damn shame but I didn`t make it that way......I`m all for personal responsibility....I was only trying to cover my rrrrsssss.

 

Frank.

 

 

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Hey Guys,

 

I think the left/right yaw thing is probably more to do with the pusher configuration of the Drifter. I presume that the motor rotates in the same direction as any other Rotax. If this is indeed the case, then rotate the motor 180 degrees through a vertical axis for a pusher installation and as far as the tail fin is concerned, it's rotating in the opposite direction. The effective opposite shaft rotation is countered by fitting a pusher prop but the end result is a prop wash spiral of the opposite "hand", striking the right side of the fin rather than the left.

 

Those of us who are "tractor drivers" (airscrew on the front) are used to the secondary affect of fire-walling the throttle in flight, the nose of the aircraft will move up and to the left. With the Drifter I'd be willing to bet that in the same situation the nose goes up and to the right due to the opposite rotating prop causing an opposite wash, striking the fin on the opposite side (the right).

 

;)

 

-PF.

 

 

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Hey Guys, With the Drifter I'd be willing to bet that in the same situation the nose goes up and to the right due to the opposite rotating prop causing an opposite wash, striking the fin on the opposite side (the right).-PF.

PF, Have I got you right?...Are you saying that a Drifter prop rotates to the left, anti clockwise, looking foward?

 

Frank.

 

 

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Hey Frank,

 

Yep, but I'm making the rash assumption that the motor rotates the prop in the same direction as any other Rotax, i.e. from the non-prop end, and looking over the motor (i.e. as you would see the prop from the cockpit of a tractor aircraft), it goes clockwise. From the motor's perspective it's still going the same way (up on the left, down on the right), but it's facing backwards, so from the tail's perspective it's going the other way (down on the left, and up on the right).

 

...of course, Rotax could solve this by having a special pusher gearbox (to reverse the shaft direction), so you can then use a regular tractor prop! In this case though, I think you'd get a left yaw from the prop wash.

 

Is there a Drifter Driver out there who can tell us which way its done?

 

:)

 

PF.

 

 

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Well it is pusher prop because the engine position defines the configuration rather than the prop I guess. I think you may be mistaken about the direction PF you turn it on the vertical or horizontal axis the direction is still the same. If you have a tractor than as you see the prop from the cockpit it will be rotating anti-clockwise... Unless the different gear boxes play a part? E type is clockwise.

 

 

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Hey PF, The prop on the Drifter ( All the ones that I`m aware of anyway ) rotate to the right or clockwise looking foward, however, it has little to do with the fact that the engine is a Rotax and that it is a pusher configuration, it is because the prop is driven through a gearbox,which causes it to rotate in that direction.

 

My first aircraft had a pusher, Fuji Robin 440 engine, but the prop was driven through a reduction timing belt drive, which gave it a left hand or anti clockwise rotation.

 

The direction of the rotation of the prop is not determined by the position of the engine.

 

Cheers,

 

Frank.002_wave.gif.62d5c7a07e46b2ae47f4cd2e61a0c301.gif

 

 

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Hey Frank,of course, Rotax could solve this by having a special pusher gearbox (to reverse the shaft direction), so you can then use a regular tractor prop! Is there a Drifter Driver out there who can tell us which way its done? :)PF.

FP, forgot to add that a standard Drifter with a Rotax motor and gearbox, can in fact use a right hand rotating prop from a tractor, ( left side up , right side down ) the pitch and diameter

 

simply has to be correct and of course the bolt holes have to be correct also.

 

Frank.

 

 

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Heh,

 

I stand corrected!

 

One last thing though, If you took the motor on your drifter, and put it on the front (somehow) with the top still facing up, wouldn't the prop spin in the opposite direction as viewed from the tail? Wouldn't you be flying in reverse if you didn't change the prop or the rotation of the driveshaft?

 

Ahh, it doesn't matter, as long as it flys right?

 

Might be time for a pre-bed snack...humble pie for me perhaps?035_doh.gif.37538967d128bb0e6085e5fccd66c98b.gif

 

PF.

 

 

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FP, It doesn`t matter whether a 2 stroke motor is upright or upside down, on the front or the back..... My motor is upside down but the prop turns clockwise when viewd from behind, looking foward, left side up, right right down.

 

Due to the high revolutions of the motor ( 6800 RPM ) a reduction gearbox is required , so theoretically, it doesn`t matter whether the motor is fited front or back, all that`s needed is the gearbox to turn the prop in the desired direction.

 

Frank.

 

Ps, No need for humble pie. There`s always something more to learn, for all of us.

 

 

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PF said ....One last thing though, If you took the motor on your drifter, and put it on the front (somehow) with the top still facing up, wouldn't the prop spin in the opposite direction as viewed from the tail?

 

Yes mate you are correct about that and a different prop has to be used if you go from pusher to tractor.

 

 

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Hey guys, I just loged on and I find an optimistic symbol on this post. I`m wondering why I`m being optimistic with what I`ve said.

 

FP, forgot to add that a standard Drifter with a Rotax motor and gearbox, can in fact use a right hand rotating prop from a tractor, ( left side up , right side down ) the pitch and diameter,simply has to be correct and of course the bolt holes have to be correct also. Frank.

Based on what I know, I don`t think there`s any such thing as a 'pusher or tractor' prop on the types of aircraft most of us here fly. All the props I`ve used could be bolted on either side of the hub face.

 

Assuming the shaft is rotating in the same direction, (both pusher and tractor), the prop is bolted on one face of the hub for the pusher and the othere face of the hub for the tractor. In both cases the the prop will face and spin in the same direction.

 

I don`t know if some props can only be bolted on one face of the hub and someone might like to tell me.

 

Frank.

 

 

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