Well, a Columbia has long been on my wish list…and Michael you’re doing a good job of selling it!
AnthonyQ wrote:
Well, a Columbia has long been on my wish list…and Michael you’re doing a good job of selling it!
Well the truth be told: I envied the Ovation ever since it came out …
Then, about a year ago, I was asked to broker a Columbia 300 . Since they’re pretty rare in Europe, this was the first time a got a good up-close look. I had a buddy that now owns a Mooney Screaming Eagle come over and have a look-see at the Columbia in my hangar. He actually was a co-owner on this very plane when it was new. He looked at me and said “Michael, this plane is BETTER than any Mooney in every single category – you should buy it !” That evening I did a side-by-side comparison of the POHs. He was right: the Columbia 300 goes faster, further, with more load and more doors and more cabin than an Ovation. Then there’s the fit & finish and the utter SIMPLICITY of the design. I look after 3 Ovations, so I know the type well.
So I bought it. Paid 60% of the price of a comparably fitted & timed Ovation. 
The Lancair Columbia / Ttx is the most over-looked plane on the market, largely eclipsed by the commercial success of the Cirrus.
I’ve owned both a Robin HR100/200 fixed gear and a Robin HR100/285 retractable. At the 200’s low level cruise at 75% power the 285 would be about 10kts faster at an equivalent power setting. At the 285’s low level cruise at 70% it would be 15kts faster than the 200 at 100% power. So the advantage grows at higher speed just as expected.
However there are disadvantages with RG (hung up nose wheel):
I would also agree that the speed increase of a 4 seater piston RG v FG is up to 20 knots.
On some of the more dragier airframes it makes sod all difference if the gear is up or down.
Not all airframes benefit the same as a retractable.
However, a sleek airframe design is hugely benefiting by tucking the gear away.
Such an efficiency increase will result in a lower fuel flow at a given speed, better overall range, lower CHT’s at a given fuel flow and less sensitivity to speed loss when faced with a headwind during cruise.
Usually, but not always, other benefits come into play that the RG has a higher service ceiling and it will climb better due to less drag.
That does not mean other designs are less worthy, of course.
But the discussion is about sturdiness and efficiency.
Apologies for injecting a bit of fact into this debate…
So I do a simple back-of-the-envelope calculation: I estimate the frontal area of the SR22 to be around 4 square metres – simply from looking at the POH diagrams and using a ruler. 1.5 for the cabin, 2 for the wings, 0.5 for the empennage), and from the same diagram, you can estimate the frontal area of the landing gear as around 0.3 sqare metres, or around 7% of total area.
Assuming that the drag coefficient for the gear is around the same value as the aircraft overall (I can’t get any sensible approximation, since drag coefficients for wings are given per wing area, not frontal area, while drag coefficients for objects in wind are given per frontal area), that would put the drag penalty of the gear in the magnitude of 5-10%.
5-10% more drag translates to a 2.5-5% speed penalty, so at around 200kt TAS this means a 5-10kt speed penalty for the fixed gear.
Given interference drag, and some problematic characteristics around the wheel itself (gaps, rubber sticking out) I guess at the upper end of that range. The weight of the retractable gear is negligible that far high up the drag curve.
So – I put my neck out – the speed penalty will be around 10kt. It is unlikely to be around 5kt, and likewise unlikely to be 25kt.
What would change this estimate?
Where is bookworm when you need him???
Hmm.
Well, estimated calculation back and forth:
I can confirm that with gear tucked away only opening the small cowl flaps on my RG reduces cruise speed by 5 knots.
Lowering the gear into the wind makes a much bigger difference!
Well, that would be 40hp wouldn’t it?
Sorry, after I have replied you have added more detail to your post.
At that speed it’s just under 30hp.
Btw your post does not say it’s been edited….
That is true. It used to do that, but because I (a) virtually never edit someone else’s post and (b) frequently edit peoples’ posts to fix up stuff like corrupted quotes, corrupted copied/pasted text, non-working image links (etc etc etc) it then looked like I was editing a lot of posts to change their meaning etc, so we removed that feature for mods. Nothing sinister
