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Advise a buyer on a 2004 2K vs a 2006 SW... both nice birds?


Acensor

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I have a CT2K and I love it.

 

I think the wing design and profile is the same as the SW... It’s just 2.5 feet (9%) longer.

 

I wouldn't expect the longer wing to be faster. In fact, you usually clip wings to go faster. I certainly haven't noticed a speed advantage in the flights I've made with CTSWs and CTLSs at Page... but I don't think I give up much either.

 

What I would expect is a slightly lower stall speed. Indeed, lift is proportional to the wing area, so at any given speed and angle of attack I have 9% more lift to work with. That doesn't do anything for me in level flight where pitch is adjusted so lift matches the aircraft's weight. But it does help when the coefficient of lift runs up against a hard stop, like the stall angle. But lift is also proportional to the square of speed, so all the 9% extra area only buys me is 4% lower stall speed. That’s less than 2 knots. The performance numbers in the handbook don't even show a difference. None the less, I do feel justified in claiming to be able to land and take off in a shorter distance, all other factors being equal.

 

The higher aspect ratio should also result a higher maximum L/D (lift to drag ratio). That occurs around 80 knots so I think I can probably climb out faster and steeper than the shorter wings, and if I was cruising at such low speeds, I would use less fuel too. Again, the handbook doesn't even bother with the difference - the stated performance of the two planes is the same.

 

I suspect my landing patterns are a little flatter too, and if I come in hot I'll float longer. Thats not desirable. I think that's why Flight Design changed to the shorter wing - to make it easier to land. I admit to occasionally putting some pretty hefty loads on idle stop and I've become proficient at side slips.

 

My 2K has the chute but there are other features on the later planes that I don't have. The CTSWs have three axis trim, I have one... but I don't miss the others. The SWs have heavier duty wheel struts and engine mounts. I don't think that came out on the first SWs - I think it was phased in a bit later – But I think it’s well worth the added weight. The instrument panel layout on the SW is a little nicer too. There is an issue with the engine cases on early aircraft. Rotax does not offer a TBO extension for them. Again, I think that issue affects early SWs as well. I'm suspicious that there may also be a difference of a degree or two in the angle of incidence of the wing, but I have not seen that mentioned anywhere. Does anyone know?

 

All-in-all there's not a whole hell of a lot of difference between a CT2K and a CTSW. I think there are more significant differences between the CTSW and CTLS, but I'll leave that for others to argue.

 

Mike Koerner

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Nice analysts re: wingspan effects.

 

As far as three axis trims, I have the same reaction as I do with three glass panels in an LSA - Why?

 

Historically, virtually no small planes ever had anything other than pitch trim.

 

Rudder trim only came with more powerful engines, where holding prolonged right rudder in a climb could get tiring*.

 

Aileron trim was unheard of.

 

Sky Arrows have the option of rudder trim, but it's only added as part of a "handicapped kit" for people without use of their legs. For regular folks I guess they figure it's just not worth the additional weight and complexity.

 

I guess each could be considered "nice to have", but there is no free lunch - more systems means more weight and more complication.

 

Anyway, I would not kick three-axis trim out of bed, so to speak. But it's presence or absence in a small plane would not be a deciding factor, for me at least.

 

 

* The very first Cirrus SR22's were equipped with rudder trim. That particular install was problematical, and was eliminated. Mine did not have it, and even with 310hp the right rudder needed in the climb was not a major hassle. Only much later could you buy a Cirrus with a full yaw damper, emiminating the need for rudder in the climb, or elsewhere for that matter.

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Rudder trim is not only useful for flying coordinated it is my #1 tool for fuel management.  I disagree that it isn't a big deal in a CTSW, without 3-axis I would have a heavy wing when solo or with passenger (take your pick) and would need rudder pedal pressure much of the time, no thanks.

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I agree with ED.

 

Just because older aircraft didn't have it doesn't mean it isn't valuable. It means to mean that others have progressed passed old way thinking and older aircraft failed to perform to a higher standard early on. Just like Rotax moved away from old air cooled, loose tolerance heavy engines like Cont. and Lycoming.  It shows forward thinking and throwing away thinking that holds you back.

 

I'll take three axis trim any day and the weight is marginal.I can trim and fly hands and feet off for quite a while in smooth air. That just reduces pilot load. If you want to save weight then you wouldn't carry all that extra gear that you have in the plane. 

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I will stipulate the CT is an odd duck in this case.

 

I have flown a lot of high wing small planes without a L/R selector, and none required continued (slightly) uncoordinated flight to balance fuel.

 

But if that's the case here (bug or feature?), I can see how rudder trim would help.

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There are other GA aircraft over the years that have been the same way. I believe if you really were exact you would find the panel and the instrument slightly out of perfect trim. Flat fuel tanks make this show up a little more than another style. It would be more critical. What's the difference in saying a plane that drops a wing hard in a stall is bad verses our plane that doesn't? It's just a quirk of that plane and something the owner should know and not be afraid of. It's all education. 

If you own a Ford it's different from a Chevy.

 

It's not for the progressive people or Mfg's to slow down and wait for others, but for others to hurry and catch up.

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I have three axis trim, but I don't use it (yet) for fuel management. The legs I have flown so far have been short, so if I notice a fuel imbalance I just put the ball out a little with the pedals and hold it for a few minutes. Where I have used the trim is when flying and notice a slight roll or yaw imbalance, whether caused by a passenger, wind, or whatever. If I'm cruising straight and level and notice an imbalance, I will trim it out. It usually takes very little rudder trim to make a change, aileron takes more turns to get results.

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I ask BRS directly that question about opening speed. It will open just fine well past our published Vne speed and carry more weight than 1320.

 

It isn't the issue of the parachute opening, it's the airframe. Past 124 kts in a CTLS, the chance for recovery begins to drop, because the stress on the airframe is so great.

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TAS is calculated two ways dependent on speed.

 

For low speeds, the static air temp, pressure altitude and IAS (which is affected by wind). Above approximately 100 knots, the compressibility error rises so TAS is calculated by the Mach speed.

 

(predict this opens up the usual arguments over the basics now)

 

IAS is not affected by wind (while in flight)

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CTLSi,

 

You are right that TAS and IAS are related.  Wind does not affect either it affects your ground speed.

 

Altitude reduces your IAS and TAS adjusts for that reduction.

 

Today there is a 10kt east wind at 10,000'  

  • As I fly west WOT my IAS will be ~ 105kts, TAS will be 123kts and ground speed 133kts.
  • As I fly east WOT my IAS will be ~ 105kts, TAS will be 123kts and ground speed 113kts.

There is a wind today but it does not affect TAS or IAS only GS.  We fly in the relative wind.

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Eddie, as for the 3 axis trim. I think with the smaller and lighter plane the trim is more important. Just by adding or taking away a passenger you will need to make a correction in roll. For a long cross country having to hold the stick all the time to keep wings level would be a big deal, especially in someting that has lite stick forces like a CT. The CT also has some pretty big changes in yaw for such a low powered airplane. If you are flying for much time at a different power setting the rudder trim is needed. I do flight training with a power setting of about 4800 so I stay close to Va. I want the airplane trimmed hands off for the student, so they are not always fighting it. When I go some place I turn 5300 for cruise, and I also want the airplane to fly hands off for a lighter work load.

I know some people with another small airplane that with 2 people moving just thier heads from side to side could make the airplane turn

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Good points.

Just by adding or taking away a passenger you will need to make a correction in roll.

 

Not in a tandem!

 

But I get your point.

 

I remember in my Tiger in smooth air if trimmed properly I could  maintain altitude by just leaning forward or back a hair.

 

Maybe I am a luddite, in that none of the plane's I've owned have had anything other than pitch trim, and I've found that perfectly adequate.

 

But I can see how they'd be nice to have.

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Eddie, as for the 3 axis trim. I think with the smaller and lighter plane the trim is more important

 

I guess it depends on the plane.  I have trim tabs for aileron and rudder that I pretty much have set and not adjusted in many years (other than when my rudder tab was inadvertently bent the wrong way).  I need very little stick pressure, if any, to keep the wings level.  Ball stays centered with minimal rudder.  3-axis electric trim wouldn't buy me much.

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The CT can hold 100 lbs of fuel in each wings, and the thanks are far from center.

Flying solo...you want more  fuel on the right sight..but no selector valve :angry:

I'm seriously thinking of installing a valve for the right wing, so I'll burn the left side first

I have only the pitch trim,,,   and a couple of small bungees

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I guess it depends on the plane.  I have trim tabs for aileron and rudder that I pretty much have set and not adjusted in many years (other than when my rudder tab was inadvertently bent the wrong way).  I need very little stick pressure, if any, to keep the wings level.  Ball stays centered with minimal rudder.  3-axis electric trim wouldn't buy me much.

 

Only the new CT's have electric trim from the factory, and it is only for pitch.

 

There are many planes that just have fixed trim tabs, and they work OK. The thing is the trim can only be set for one speed and power setting. If that is where you fly most of the time it will be OK, but if you are trying to fly at a different speed or power setting it will be out of trim.

 

I flew a Thorp T18 to Oshkosh this past year. I checked out in the airplane the day before we left for the trip. With 2 of us in tha airplane it flew fairly wings level. When I departed the next day the airplane was had a faily significant roll to the left because I didn't have the right seat passenger. At our fuel stop they adjusted the trim by massaging the aileron, and put in to much correction. Now it was rolling to the right. For my trip home I knew I would have someone in the right seat, so we made another thrim change. I still had to hold some aileron pressure all the way home. Aileron trim sure would have been nice for that trip.

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Only the new CT's have electric trim, and it is only for ......

Guess that depends where you draw the line fir "new."

I flew a 2006 SW yesterday and it had three way electric trim. Owner said he's almost never use anything but pitch trim.

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