Stability in rough air ?

[Tomo]

We did notice that people who could ride a horse or did a lot of work off the back of a moving ute handled the rough better, even reducing the bounce. I wonder if it works for people with a bit of sea faring experience?

Good point Sue - an interesting one too.

 

I've never been bothered with the rough (as in getting sick) as I've been doing pretty much everything you mention above since I was knee high to a grass hopper.

 

But I felt a bit queazy going in an Airliner for the first time because they were so still. So what you say could have merit both ways.... :confused:

 

I agree with Blueshed about the side to side motion, one of the reasons people can get quite sick in coaches, especially double decker ones. The joke used to be the people up the top were just scared sick because they haven't a driver. ;) But it was really the swaying motion that set it off I reckon.

 

The Morgan Sierra I flew in the other day was very stable, what I mean by that is, it did what you told it to, and trimmed and stayed where it was put. Really like most aircraft properly rigged should. You still had to correct for a wing lift or whatever from turbulence, but nil rudder was needed to put it back. In other words, it just rolled around it's nose in turbulence, no side to side waving of the nose. Even with aileron input. It was a very comfortable for seating and plenty of room. Really they're much the same in performance as the Pioneer Hawk or similar - but half the price. And you can get rid of the wings for storage/trailering.

 

High/low wing... I dunno, I find the low wing more abusive in turbulence than high wing, not sure it it's just placebo effect, or it really is. My low wing experience has been limited though, so not really a fair average between the two at this stage.

 

 

[Neil_S]

Hi Facthunter et al,

 

Well, my wife is OK flying in "big" planes (eg 747), but simply does not like "small" planes (eg the Gazelle). I believe the Gazelle would tick most of the boxes you mention, but she does not like the full size perspex doors in the Gazelle (and I probably shouldn't have told her it is certified to fly with the doors open :hittinghead: ).

 

So I don't see any real prospect of her coming flying with me any time soon, sadly....

 

Cheers

 

Neil

 

 

[Guest ozzie]

I think that there may be some confusion as to whether it is ride comfort or aircraft handling stability that you are talking about.

 

Go for a ride in a Nan Chang on a thermally day. It is built like the brick proverbial and rides like a truck with solid rubber tyres. there is n ive or flex in the airframe the wings are solid and the shock is delivered right to the seat . on the other end of the scope a sailplane has long flexible wings and it can absorb most of the harshness of the turbulance the wings almost flap up and down. given how the pilot is seated in a supline way the shock of the ride is absorbed by more of the body rather than by two small butt cheeks. This goes to say also how the seat is manufactured with it's cushioning.

 

The aircraft stability comes down to the design factors. one is indeed the wing loading my Lazair with it's very light loading bounces more like a cork in the ocean. But it does not jar. Stability comes down to things like roll rate and pitch rate. short coupled or long coupled in pitch ect. If it is ride comfort you are concerned about sit on the centre of the wing and build your seat out of several different densities of foam. dynamic stability of the design also comes into play how fast will it come back to it's previous attitude? ect ect . enough for now it's almost beer oclock and as fred says it's quiting time.

 

 

[Ultralights]

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[bacchus]

Thanks for that " Ultralights "

 

I guess I will keep saving for an F16

 

 

[djpacro]

If anyone would like some bedtime reading -NASA CR-1975, Riding and Handling Qualities of Light Aircraft - A Review and Analysis is free online (12 MB pdf) at http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19720018355_1972018355.pdf

 

Page 187 onwards is relevant - Design for Desirable Riding Qualities. You can ignore the arithmetic and associated text - just consider the general remarks.

 

 

[Guest rocketdriver]

Too much information, DJP. It makes me realise how much I have forgotten! LOL. All those half (actually mostly) forgotten Laplace transforms etc etc ..... but interesting non the less ... TKU!

 

RD

 

 

[facthunter]

Stability. Of Aircraft.

 

Since I have referred to stability a few times, I am talking about the stability of the AIRCRAFT, itself. Not it's controllability in rough air. 2 different things and one can act against the other. The aircrafts stability is affected by things like dihedral, wing sweepback, high wing, rudder and fin size, Keel surface area in relation to the Cof G. Tail moment arm and tailfeather area. Position of the CofG and the last two mentioned, affect pitch stability. You can also have spiral instability. Big interesting subject, but the point I am trying to make is that if the plane is very stable you have to put bigger control inputs into it to get it to manoeuver quickly..Nev

 

 

[Guest drizzt1978]

Ok, I have flow a Jab 160 -170 and a texan and a 230. All with the Fiance,

 

The 230D is far superior in turbulence in terms of seat of the pants and complaining passangers. Infact my Fiance swears the texan is bumby and makes her feel sick! So there is some seat of pants analysis!

 

Michael