Mooney Acclaim vs. Columbia 350/400 (which has fixed landing gear??)

"Justin Gombos" wrote in message
news:HNFbi.8949$Ar5.5244@trndny01...
Doesn't it bother you Columbia fanatics that the manufacturer designed
the landing gear to be fixed?


Not at all.

Here's a pricey high-end aircraft where
most of the design decisions favored speed and range, then they
compromised the aerodynamics of it by using fixed landing gear.

Retractable gear would have added over 120 lbs to the weight and gained
about 3 knots.


Columbia is claiming their 400 model is the fastest single engine prop
aircraft on the planet (max cruise speed of 235 kts on their
comparison chart), though it's surprising that they can claim that
title with fixed landing gear.

Super-clean design, high aspect ratio wing...

That number is probably worthless
since the manual spec'd the never exceed speed to be 230 kias.

INDICATED Air Speed, not TAS (you do know the difference, don't you?

Mooney is also claiming to have the fastest single engine - in their
Acclaim which allegedly has a normal cruise speed of 237 kts (at
FL250), yet Columbia is claiming that the same model has a max cruise
of 220 kts. The Columbia has 40 HP more, but I'm inclined to think
that some of that extra horsepower is being wasted on the drag of the
landing gear.

Not to mention the much bigger/wider cabin.


Mooney didn't publish their manual, so a realistic comparison on the
performance is difficult. It's not real useful to compare marketing
spin to marketing spin, or even the Columbia manual to Mooney's
marketing spin.

How about cost of insurance?

Does anyone have a better idea of the performance and
efficiency differences?

I can verify the C400 numbers, at least to 21,000 feet. As for the Mooney,
it achieves it's performance (a review by FLYING, verified them both at
235kts. IIRC, the Mooney would be running hotter to do it.).

BTW, is the Columbia they only single engine prop that has a side
stick?

Nope, Cirrus.
--
Matt Barrow
Performace Homes, LLC.
Cheyenne, WY

On 2007-06-13, Matt Barrow wrote:

Retractable gear would have added over 120 lbs to the weight and
gained about 3 knots.

Good point, if it's true. So the question is why would retractable
landing gear ever be used? Are there any publications to support the
idea that fixed landing gear induces such an insignificant drag?

That number is probably worthless since the manual spec'd the never
exceed speed to be 230 kias.

INDICATED Air Speed, not TAS (you do know the difference, don't you?

Yes, in fact I have a PC. The figure from Columbia I was comparing
that to did not specify TAS - and a TAS figure is worthless without
other parameters, so I naturally expected it to be in KIAS or KCAS in
that context. But after looking at the cruise performance table for
25k ft. in the Columbia 400 manual, I can see that marketing was using
a cruise TAS value assuming everything pegged at max altitude.

How about cost of insurance?

I've never shopped it out. What difference can I expect?

--
PM instructions: do a C4esar Ciph3r on my address; retain punctuation.

Justin Gombos wrote:
On 2007-06-13, Matt Barrow wrote:
Retractable gear would have added over 120 lbs to the weight and
gained about 3 knots.

Good point, if it's true. So the question is why would retractable
landing gear ever be used? Are there any publications to support the
idea that fixed landing gear induces such an insignificant drag?

Well, it's not a "publication" as such, but a couple guys on the VAF forums have
built/flown RV-4's with retractable gear. One guy built two airplanes, one retract and
one fixed, and said the performance (speed for a given power setting) was virtually
identical. The fixed-gear one not only weighed a fair bit less (as expected), but also
had more fuel capacity and higher structural limits (due to the location of the landing
gear).

Justin Gombos wrote:



How about cost of insurance?


I've never shopped it out. What difference can I expect?

I pay $1900 per year for my apparently now passe' Bonanza. If I were to
buy a new Columbia I would be looking at at least $8-10,000 per year for
the same insurance. I have 250 pounds more useful load than the
Columbia with 300 pounds less gross weight(3300 vs 3600 lbs) so it looks
to me as though the Columbia is already a bloated pig. Pretty small
tires, better stay on the pavement, a deal breaker in my book. A high
stall speed, another downer. As far as I can see all I give up is
speed, not a fair trade.

"Newps" wrote in message
. ..


Justin Gombos wrote:



How about cost of insurance?


I've never shopped it out. What difference can I expect?

I pay $1900 per year for my apparently now passe' Bonanza. If I were to
buy a new Columbia I would be looking at at least $8-10,000 per year for
the same insurance.

I'm paying $4735.

I have 250 pounds more useful load than the Columbia with 300 pounds less
gross weight(3300 vs 3600 lbs) so it looks to me as though the Columbia is
already a bloated pig.

Is your's certified in the "Utility" category? Does it have dual everything
including dual wing spars?

Does yours have A/C and anti-ice/de-ice?

Pretty small tires, better stay on the pavement, a deal breaker in my
book. A high stall speed, another downer.

60 knots is a high stall speed? If it does stall, it won't spin like your's
will.

As far as I can see all I give up is speed, not a fair trade.

Next time you're in your Bo, raise your knees six inches, or expand your
shoulders...

Matt Barrow wrote:

I have 250 pounds more useful load than the Columbia with 300 pounds less
gross weight(3300 vs 3600 lbs) so it looks to me as though the Columbia is
already a bloated pig.


Is your's certified in the "Utility" category?



Yes, up to gross weight.


Does it have dual everything
including dual wing spars?

No idea.



Does yours have A/C and anti-ice/de-ice?

No, that's why the Columbia is a bloated pig.




Pretty small tires, better stay on the pavement, a deal breaker in my
book. A high stall speed, another downer.


60 knots is a high stall speed?


Yes.



If it does stall, it won't spin like your's
will.


Mine doesn't spin in a stall. I believe that's a certification requirement.




As far as I can see all I give up is speed, not a fair trade.


Next time you're in your Bo, raise your knees six inches,

Why?


or expand your
shoulders...

How do you do that?

On 2007-06-15, Matt Barrow wrote:
60 knots is a high stall speed? If it does stall, it won't spin like your's
will.

Hmm. I've stalled an S-35 Bonanza plenty of times. It never entered a
spin.

--
Yes, the Reply-To email address is valid.
Oolite-Linux: an Elite tribute: http://oolite-linux.berlios.de

Justin,

So the question is why would retractable
landing gear ever be used? Are there any publications to support the
idea that fixed landing gear induces such an insignificant drag?


Not any landing gear. The Columbia and Cirrus gear is specifically
designed for low drag.

Why do retract at all? More drag at higher speeds (for fast airplanes),
marketing, lack of materials for efficient gear design, among others.

--
Thomas Borchert (EDDH)