Stability in rough air ?

[bacchus]

As I inch closer to making one of the larger descisions in my life ( the purchase

 

of an aircraft ) this forum has been a great source of information and an education with the level of knowledge available to us all.

 

It seems impossible to test fly ALL the aircraft in consideration , thus opinions , constructive criticism and tech data is greatly appreciated.

 

As I satisfy myself debating such things as high vs low wing , alum vs composite construction vs rag and tube , Rotax vs Jab , Aussie vs import etc I neglected to consider the most important thing , ( my wife being a very nervous flyer !! )

 

She piped up today stating " I don't care what you buy as long as it is safe and comfortable in rough conditions ".

 

So I call on the "tech heads" ( with respect ) on this forum to supply info on what makes for a stable aircraft , and ALL opinions from those who have flown many different aircraft with real life experiences.

 

Thanks in advance ,

 

I should add that I am seriously considering an Allegro 2000 but burning the midnight oil ,reading threads going back a few years raise stability questions.

 

 

[Guest rocketdriver]

Hi Bacchus

 

How rough is rough? All RA a/c react more to turbulance than most GA 'planes as RA 'planes have a lower wing loading to keep the stall speed down. Solution? Don't take the good lady flying iin strong winds or hot, thermally days ....

 

Oh, and I'm also in the decision process .... taidragger for me. I'm a bit limited in the dollar department tho' ....

 

Regards

 

RD

 

 

[facthunter]

Stability and Rough air.

 

My wife hates turbulence and always takes a motion sickness pill.

 

Low wing loadings have inferior "penetration" ie turbulence comfort characteristics. High wing loadings are better but tend to have higher stall speeds.

 

STABILITY, Sounds like a good thing to have (we would all like to consider ourselves stable wouldnt we? How do you get it? Well each axis has to be dealt with separately. ROLL and YAW affect each other because of secondary effects. You can read this up probably on the RAAus site and Wiki. and there is a bit in it. Spiral instability can be a result of attempt at too much directional stability... SO..

 

Do you want a lot of stability? I do not like too much and in fact prefer a plane that more or less stays where you put it., that is neutral. and I think that set-up works best in rough air also.

 

On your list of desireable features I would include structural strength. Understand all about that also. Compare apples with apples, don't use different parameters, and consider having an aerodynamic pitch trim, (not a spring). Safety backup. and of course consider a tailwheel A/C .. Nev

 

 

[monty]

Just my 2 cents Bacchas,

 

My wife is a nervous flyer and there are winds and thermals all the time out here in Central Western Qld. She will not fly in a mates Jab or even a cessna on a bad day because she recons you can feel every bump when you are enclosed in the aircraft, However she will fly in the Drifter on a bad day with the wind in your face you don't notice it any where near as much.

 

Thats Her opinion.

 

It depends on what you want.

 

Monty

 

 

[rgmwa]

I mostly fly a Cessna 172, and depending on the day, it can get bounced around pretty badly too. I doubt whether any light aircraft is going to be comfortable in rough conditions, although it should be safe, provided you keep your speeds in a sensible range.

 

rgmwa

 

 

[Yenn]

High wing loading is the answer. The C182 was a good steady platform. The Fokker Friendship was poor in turbulence. The Jabs' Gazelle, Skyfox types I have flown were a bit rough, but for some reason the Thruster was not as bad, maybe the all fabric wings acted as shock absorbers. The Corby Starlet is great in turbulence and I can't remember what its wing loading is. The old Victa Airtourer has given me a few rough rides and it has a fairly high wing loading. All this is saying it is mainly wing loading, but some planes seem to negate the theory.

 

 

[facthunter]

Another factor.

 

SPEED. The faster you go the harder the encounter with up and down drafts. (slowing up reduces the loads imposed on the airframe as well as the discomfort). Also some wings flex a lot. While this looks bad, it must help. The F-27 Fokker wing did not flex in turbulence very much, and had a high aspect ratio, which probably makes the effect similar to a larger wing area. Nev

 

 

[sfGnome]

...and of course consider a tailwheel A/C .. Nev

Can I ask a dumb question? Was the reference to tailwheel serious, or just because you like flying them and just threw it in? If you were serious, what difference do they make? (I'd actually like to know all the reasons why some people prefer tailwheel, but that'd be a hijack of the thread so perhaps I'd better start a new one :) )

 

 

[facthunter]

Tailwheel?

 

Sure , it's a genuine suggestion to CONSIDER a tailwheel. Are you SERIOUSLY suggesting that someone should NOT consider a tailwheel A/C? Are they really that "passe" in your mind? Re-enforces the need to suggest the consideration.

 

This subject has been exhaustively debated here before. Personally I cannot be bothered going through that process again. Someone may be able to provide a link so that a lot of good ^ bad comment may see the light of day again. Nev

 

 

[Ultralights]

i have found high wing is generally more stable than low wing, high wing aircraft tend to have a lot less dihedral compared to low wing, as the weight of the fuselage below the wing tends to keep it more level in rough air, but this is just an observation of mine,

 

Something else i have noticed with the Savannah we have now is that with the very low wing loading, you still feel the bumps, but they tend to be softer bumps when compared to flying a Jabiru in the same conditions, think of the sky full of cotton balls and bouncing around through them, the aircraft still rocks around and changes direction, but there are far less sudden jolts. could this be why the very low wing loading aircraft like drifters and thrusters dont seam so bad in turbulence?

 

 

[monty]

Hi Ultralights,

 

I agreee with the softer bumps bit. If it is rough I fly about 46/48 knots and it is real soft and comfortable it does move around a bit but still handles and feels very safe. I think that is a part of the fun flying one of the old style Rag and Tube ultralights and it's a "TAILDRAGGER"

 

Monty

 

 

[sfGnome]

Sure , it's a genuine suggestion to CONSIDER a tailwheel. Are you SERIOUSLY suggesting that someone should NOT consider a tailwheel A/C? Are they really that "passe" in your mind? Re-enforces the need to suggest the consideration.This subject has been exhaustively debated here before. Personally I cannot be bothered going through that process again. Someone may be able to provide a link so that a lot of good ^ bad comment may see the light of day again. Nev

Nev. I didn't mean the question in any negative way. Quite the opposite. I've recently seen an opportunity to do a tailwheel conversion and I've been wondering to myself whether there's any value in it - I mean, are there significant advantages (and disadvantages?) compared to flying a nosewheel a/c, or is it just a different skill and nothing more. Hence, when I saw your comment about tailwheel in the context of stability in rough air (and given that my wife gets very scared if the a/c moves any direction other than forwards), I thought I'd ask whether that was one of the advantages of that style of a/c.

If a taildragger will make her more comfortable in the air, then I'll be shelling out the shekels for the training faster than you can blink. :)

 

 

[facthunter]

response

 

sfGnome. Go for it. The tailwheel THING WILL NOT MAKE ONE IOTA OF DIFFERENCE IN THE AIR. Look at the difference between the Gazelle and the skyfox/(from which it evolved). the Gazelle is about the most forgiving aeroplane I have ever flown. The skyfox( the taildragger version and predecessor) is just the same aeroplane in the air but on the ground is a whole different beast. It requires a fair bit of concentraton to master it on the ground. By all means do a T/W conversion as it will increase you awareness of the need for positive use of rudder. I reckon that only about 5% of pilots fly tailwheel aeroplanes, these days. In extreme conditions I believe that you have more positive control of them in the landing phase than you do with tricycle ( N/W) aircraft. The nosewheel is definately a failure prone element of the aircrafts structure as it can easily be overstressed.

 

I believe that there is a very good case to have a new reassessment of the value of the T/W configuration. It requires extra training but has rewards that make it worth the effort. I don't recommend it for ALL pilots . In fact I cannot remember one case where I have recommended the purchase of a T/W A/C to any student that I have been involved with. If you accept this fact then you have to concede that I am not seeking to justify what I personally do. My recommendations are without prejudice in this area. Nev

 

 

[farri]

( my wife being a very nervous flyer !! )She piped up today stating " I don't care what you buy as long as it is safe and comfortable in rough conditions ".

.

First question is, " How rough is rough",second is,"How safe is safe" and thirdly and the most important,is," How experienced and skillfull is the pilot".

 

" All aircraft obey the same laws of physics".

 

Cheers,

 

Frank.

 

 

[bacchus]

Thanks all for the info , Interesting comment Ultralights regarding wing loading and the Savannah , as I personally have found my mates Savvy XL a little more comfy in rough air than the sportstar I am used to flying.

 

As far as how rough is rough ? how safe is safe ? and how experienced is the pilot ? whilst all valid questions in their own right , are pilot descisions and are to be answered by any pilot prior to flight, however in this discussion are totally irrelevent !

 

For the excercise , choose your own hyperthetical conditions , make them challenging , and then apply the aircraft which we fly , some will perform better than others from a comfort perspective , my question is which ones and why ?

 

There is no doubt that from a nervous flyers point of view the more " comfortable " the ride , the " safer " they feel , which in turn makes my flying a lot more pleasurable.

 

 

[FlyingVizsla]

An interesting aside - some pilots make their own turbulence. I had a young instructor who started his career working (washing planes, answering phones & occasionally flying) for an old mustering pilot. One day Young bloke was doing the flying and bouncing around. Brian told him he could see the clear air turbulance and so took over to show him how to ride the bumps, holding the yoke with one or two fingers, bearly moving. Young instructor held him in awe for years. Brian confided to me that young blokes fresh from training in the city tensed up in the thermally air in the outback, held the controls in a vice like grip and overcorrected leading to more and more bumps - effectively creating their own turbulance.

 

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?

 

Sue

 

 

[blueshed]

Hi Bacchus

 

Just something I noticed between a few different aircraft, Tecnam Sierra & J230, Jab seems to have less adverse yaw in bouncy conditons compaerd to the Tec. Which meant I was trying to chase the yaw and not as comfortable.

 

The Gazelle seems to ride the bumps, probably because it is only doing 65kts, maybe 70kts. How far do you want to go? Round the country or round the state? or just your local area. Are you going to put it online for hire etc?

 

Then I only have .5 of an hour in a Gazelle, however am working on a few more in the Skyfox since purchasing one late last year, got a trailer for it too, now I can go IFR ( I follow roads!) Good way togo if you are going to travel Oz!

 

 

[bacchus]

Hi Blue Shed ,

 

IFR " very good " permission to use that one !!!

 

How far ? Ideally , eventually , would love to do most of OZ . The good lady

 

is hanging to get to El Questro Station in the top of WA and myself a trip from Adelaide to Boraloola or Normanton for a little Barra fishing.

 

Adverse Yaw !! I was hoping someone would bring that up !! According to those who have flown Morgan Aeroworks aircraft they are meant to be very stable ( I have never flown so stand to be corrected ) Interesting that those aircraft are supposed to have very limited or no adverse yaw ??

 

 

[blueshed]

May be I used the wrong terminollagy (Not refering to "Adverse Aileron Yaw"). Just the tendancy for the aircraft to move uncomfortably in the yawing plane. I find that upsetting, more that just the average bump!

 

Don't mind bing pushed in or out of my seat, dislick being pushed sideways Though!!!

 

Sorry to have miss lead!

 

 

[facthunter]

Yaw.

 

Bit hard to avoid that. Moving (Gusting/Turbulent)air does it in ALL directions and when it pushes on the keel surface the plane reacts and you feel it. It will tend to weathercock into wind (it's designed to do that) too, making the whole thing a bit more complicated to analyse. I believe that a plane designed to be very stable, behaves worse in turbulence because of the way it reacts.

 

Early morning flying, or calm overcast days can give you some of the smoothest conditions for flying and in the afternoon on hot sunny days can be the roughest. Near mountain ranges when there are strong winds can give bumps that are a threat to the aircrafts structure. Never fly with the seat belt undone. Nev

 

 

[blueshed]

Agreed Nev,

 

was just sharing my experience of two different types I had flown and what I felt I had found or more to the point FELT !

 

 

[bacchus]

Thanks Black Rod,

 

As you may have guessed , The fear of flying with my wife is not a little , but considerably more than the usual.

 

And before the forum comes forward with the easy answer of leaving her at home , let me say that I do enjoy spending time with my wife , and if I wish to persue my love of flying it MUST include her or the ultimate result will be VERY EXPENSIVE and no aeroplane at all !! lol.

 

I took the opportunity to show her a few video clips of aircraft wings flapping like a seagull ( and not breaking away from the fuselage )and the wing loading demo on the Jab website to try and demonstrate the strength of the aircraft we fly.

 

Totally agree regarding the conditons and I have only taken her flying ( locally ) when they, (the conditions) are good to very good. However on a major cross country I may not have that luxury , so if that means a few extra dollars , a few less knots , a little less cockpit room or a sunburnt head ( in the case of a low wing ) then so it shall be in the quest for a stable and comfortable aircraft.

 

So the question still remains ? surely, some of you guys and gal's who have flown a half a dozen or so aircraft ( unlike myself ) MUST have a favourite or at least an opinion to which perform better.

 

Thanks Blue Shed for your input , A Fly in counter lunch at the Jamestown Hotel may be in order at a later date and Nev , you seem to talk a lot of sense.

 

Anyway it is a work in progress and I am sure others on the forum have faced the same isssues !

 

 

[Guest rocketdriver]

FWIW there used to be an organisation dedicated to helping people overcome a fear of flying ..... Can't remember its name tho' .. must be old age creepintg up on me!

 

 

[Bryon]

My missus is sh*t scared of flying and did the POP seminar by Jill Bailey at the the last Natfly at Narromine

 

She is still scared of flying but is a lot more confident that she will not fall out of the sky with every bump and takes great delight in telling me what I am doing at any given time

 

My advice is to get your missus to do the POP course. It may help ease her fears

 

I dunno which is worse, a scaredy cat who squeals at every bump, or a vicous woman who punches me every time I try a steep turn.lol

 

 

[facthunter]

Apprehension.

 

Bacchus, you are not alone. Women flying with their husbands in U/L's a pretty rare items. They don't feel safe in them. My approach to flying is to have a solid simple reliable aeroplane and until recently that was a Citabria, which is not a U/L. My wife would come on the controls for every T/O and Landing to get the feel of the plane, the idea being that she could have a good go at landing it if I got food poisoning or had an incapacitation of some kind.

 

I have a very safety focussed approach to aviation and she feels comfortable with that but is not impressed by some "she'll be right" operator's.

 

Aeroplanes do not have springs and shock absorbers etc so we are fiddling at the edges with trying to approach it that way.

 

I've had about 8 severe turbulence encounters about 3 of which could have had the most serious of outcomes and the aircraft were from the smallest to 200 seat aircraft, and I have been fortunate to fly a good cross section of the general run of U/L's. So.. MY emphasis. (Now I know we were not talking about SEVERE turbulence but it is the one that will put her off). So

 

Quite STRONG, for confidence. (this usually means a high-wing, but not ALL H/W are strong.) Basic and simple. Gravity feed fuel capability

 

Good controllability at low(er) speeds. and a separate aerodynamic trim tab on the elevator. (reason If you lose elevator function you are going to be dead).

 

Medium speed aeroplane up to 110 Kts cruise.

 

Side by side seating (might be the best for you.)

 

Adequate to a slight excess of engine power for your operations (Payload) Gives you more authority and manoeuver options in tight landing T/O situations...

 

There's a Brumby Hi-wing being built. Check the weight. Might be a little heavy unless the weight limits are raised or maybe LSA. Sell the idea and get her to do the pre-flight checks with you and the nav and the weight and balance and.. Get the idea. Nev