Weightshift v 3 axis

[skeptic36]

Hi all,

 

Something I have been vaguely interested in for a while is the difference in flying a trike compared to a 3 axis aircraft.

 

I have 23 hrs in a trike and zip in 3 axis, I enjoy the trike, it is simple to fly, in good conditions you can take your hands off to take a pic or just relax and the thing just flys itself. It can be a little uncomfortable in rough air, but as I do it for fun I mostly leave it in the hangar when it is too bad.

 

The perception I have of three axis (based on discussion here as that is the only experience I have) is that you have to be driving a 3 axis all the time, knowing the aircrafts position compared to the horizon, making sure the angle is right for landing so the weight is distributed on the undercarriage correctly etc. (I could be barking up the wrong tree, I'm sure some of you will let me know:big_grin:)

 

There are the performance capabilities of the inclosed cockpit types which would be good if you want to be somewhere else, but I kinda like being out there with the birds and while the kids are still home :thumb_up:there isn't much opportunity for 2 people to be going too far away

 

Regards Bill

 

 

[facthunter]

Comparison.

 

Just putting a couple of points, rather than asserting the superiority of one or the other.

 

A 3-axis aircraft, properly rigged and trimmed & balanced, will generally fly itself. It should have natural stability. Some pilots don't like too much of that (myself being one), and may prefer control authority.

 

A 3-axis plane is controllable under negative "G" conditions, (even inverted) whereas a weightshift is not. That would always concern me.

 

Most 3-axis planes will spin or spiral (not the same), under some conditions, A weightshift can be designed to do neither. (Correct me if I am wrong.)

 

The out in the open "one with the sky" great field of vision, is available with some 3-axis (Not many) ie the Drifter notably.

 

Without significant keel surface, or a rudder, crosswind landings on a weightshift are harder to execute.

 

Weightshift need more power for the same airspeed that the average 3-axis, with the same payload, but take-off in shorter distances. That should get the ball rolling. Nev..

 

 

[farri]

Hi skeptic,

 

I was going to point out some differences also but facthunter has covered it pretty well.

 

Cheers,

 

Frank.

 

 

[Guest Crezzi]

Yeah I'd agree with most of Nev's observations - a very fair contribution from a 3-axis pilot ;-)

 

Just a few thoughts -

 

Trikes have never been demonstrated to spin but they do spiral dive (if thats what was referred too). Eg inadequate pitch control during steep turn. Not how (or if) that could be designed out but I never flown one that didn't.

 

Its not so much the lack of a keel which is an issue - many early trikes did have a keel though the excellent yaw stability of most modern wings makes them unneccesary. The lack of a rudder (since trikes are 2-axis control) does mean that you can't cross-control for a cross-wind landing but the quoted limits aren't actually that different to a lot of 3-axis aircraft. For example the XT912 is limited to 12kts xwind component. The landing distances are very low so, above this limit, its often possible to reduce the wind component by landing across the runway width.

 

Cheers

 

John

 

 

[farri]

The landing distances are very low so, above this limit, its often possible to reduce the wind component by landing across the runway width.

Cheers

 

John

Hi Crezzi,

 

I`ve never landed across the runway,possibly because i`ve never landed on any that were wide enough,however, in the early days I used to do a lot of introductory flights,with my Austflight WB Drifter from a strip on the Atherton Tablelands, at a holiday ranch called "Pioneer Valley".

 

There were day`s that the cross wind was sufficiently strong that I would approach the strip,on finall,at 90 degrees to the strip,into wind,then simply turn onto the strip and land,never had a problem.

 

Regards,

 

Frank.

 

" Flying Is Easy,Crashing Is Hard."

 

 

[alf jessup]

Hi Guys,

 

One main different thing to a trike compared to 3 axis is other than the obvious that they look nothing like eachother is that the key to the trike is to get it in your head that you fly the wing and not the pod when landing in a xwind, trikes are quite capable in xwind situations if you fly the wing, the pod will follow wherever you point the wing.

 

I quite often have xwind situations at my home base even though I have 3 runways to choose from, a lot of times I will reduce the xwind component by angling my final approach on our main 1500 mtr x 30 mtr sealed runway when I want to practice xwinds.

 

Mind you this often depends on the conditions, if it is gusty and some mechanical turbulence off the hangers i will use the most appropriate into the wind runway.

 

Cheers

 

Alf