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Author Topic: Geared v Straight - A spirited discussion!  (Read 9553 times)

Russell Legg

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Geared v Straight - A spirited discussion!
« on: October 10, 2015, 12:16:56 am »
Hello Folk,

The following is a series of raw conversations regarding TCFG members' thoughts/experience with operating the Geared and Straight engines as installed in piston Commanders. 
These spirited conversations are sourced from the TCFG Chatlist in the early 2000's and are strictly the opinions of members at the time.
While I am sure the experiences discussed are still as relevant in 2015, it should be noted that some key members featured have since passed out of Commander ownership.



560E s/n 726

Geared or Straight

With respect to all my friends currently flying geared engined Commanders I have recommended to Paul not to buy any airplane with ageared engine.
It's not that there is anything wrong with these airplanes, far from it. Sadly both Lycoming and Continental refuse to do anything further to support these airplanes. Parts will become more scarce and expensive. I like the idea of the slow turning quiet geared engined airplanes but their time has come and gone.
There's a reason a comparable direct drive airplane brings so much more at resale.
I bought my Colemill with very high time everything for under 50k and built a new 2001 ship "to die for" exactly the way I wanted it. Even if she was factory new I could not have done better. I now have arguably the best 500 in the world (I'm sorry to let my modesty get in the way of my true feelings).I've put alot of money into her but would get it and then some if I was to sell.
Regardless of the approach you take when buying your dream I recommend you stay away from the geared engined birds.
I hope I have not offended anyone as your Commanders are as good as any ever built but time and economics make a geared bird a less than desirable decision.
One mans opinion.

Gary wrote:
>time and economics make a
>geared bird a less than desirable decision.

Valid point Gary - especially to some just considering geting
into a Commander.
Parts are indeed becoming difficult to acquire.  They ARE
available _today_, but are hard to find.  As Gary points out,
the market prices reflect this fact: look at the asking prices
for a 560 vs a straight 500.  Personally, I highly prefer the
geared engines (from a flying standpoint).  I wish Lycoming
had continued to evolve the GSO-480 line.  By now it would
be the ideal engine for many applications.

The only debate here is the age-old Lycoming vs. Continental debate.  (It's
right up there with Ford vs. Chevy, Pratt&Whitney vs. Garrett and
Peanutbutter vs. Vegemite.)

On the Con side of the Continental,

1) Unless you go with the "Colemill conversion" you're getting less power for
the equivalent Lycoming powered airframe.

2) The reputation for crank case cracking, which Continental knows of and
allows within certain limits.  Presumably, Continental has remedied this
problem and an up-to-date replacement would fix this.   ?Anyone up to speed
on this issue?

The Lycomings seem to enjoy a better reputation -- but look how many
Beechcraft and 300 & 400 series Cessnas are Continental powered.

As mentioned by Gary Loff and echoed by a few others last night, any direct
drive engine Commander is always sought after.

I've got to agree with Capt. JimBob...There's nothing like a geared engine! I'm really glad that most people feel there's something inherently bad about them as this keeps the price of these birds down to where I can afford them.
I don't have as much Commander time as many on this list have, but I have flown 520's, 500B's, 500U's, 560F's and 680E's. My favorite so far is the 520. It's the ultimate $100.00 hamburger airplane. Incredible takeoff and landing performance, excellent cruise speed, and it's just plain fun to fly. After flying a 520, any of the 500 series birds seem to be a bit anemic. Things change when strapping on a 560F or a 680E. Push the throttles up on one of these big boys and you know you've arrived! The 560F is really a Shrike on steroids. It just out-performs them on every occasion. The only limitation with a 560F in my humble opinion is that it is an excellent flatland airplane. To go to the high country get yourself a 680E or better yet a 680F(P). If money was not a problem (Drat! I hate it that it is!) I would be driving a 680F(P) and pulling up to the pump without a care!
I would also love to fly a -FLP, however not out of my 2050' grass strip.
As to the geared engine horrors, my 520 has 1050 hrs. on one of the engines, and the gear box lash is the same as my 140 hr. 560F engines, about 1/4".
With all of that said there is one other advantage to a geared  engine in a 'Bathtub nacelle'......ain't nothing on this earth that sounds like a big geared Lycombing dumping its exhaust into four augmentor tubes on takeoff!


I agree w/ John's assessment and also highly recommend Sun West in Tucson.

I'd add that I transitioned from a Cherokee 6. I completely agreed w/ the single engine is more reliable than two or the "second engine carries you to the scene of the crash...." statistics, but knowing what I now know, the commander is the one piston twin that is the exception to that rule. I did my twin training in a dutchess and have since flown an apache(on floats) and Baron. The more I fly other twins the more I appreciate the commander!

In my training the SunWest instructor showed me a single engine stall turning into the dead engine. I don't recommend it, but I had to fight every fiber of my experience to cut the throttles on him, but in fact the plane did it and he showed that he still had full aeleron authority!

No twin is fun or easy on one engine at rotation, but most piston twins aren't safe or even capable of single engine flight at low speeds. The commander is.

The commander is the only piston twin I would encourage anyone to consider for a low time transition! The question I'd caution you to focus on is are you ready to make the commitment to a safe transition, I wouldn't even consider another aircraft.


Hi Paul,

In September of 1999 I was in exactly the same position you are. I had 80
hours: 79 in a Cherokee and 1 in a Cessna 182. Not exactly a bounty of
experience. Also like you, I arrived at Chris' Commander page, albeit
through a different path. My first inkling that there could be more to the
Commanders than meets the eye was seeing what Bob Hoover could do with one
at an airshow. My first look at his plane, I nicknamed it the "flying pickup
truck" and wondered what the heck it was doing in an airshow. Needless to
say, he blew my socks off with his routine. Anyway, I also had the great
good fortune to live about 15 minutes away from Commander Services, in
Hayward, CA, owned by Morris Kernick--who knows more about Commanders than
anyone I've been able to meet. He spent a couple of weeks educating me (with
hands-on tours!) on Commanders. By October of 1999 I was the proud owner of
a turbocharged & deice-equipped '62 500-B. Of course, I had not one solitary
minute in Commanders. Now I've got about 175 hours in my plane, and will be
completing my instrument rating within the month. So I'll answer your
questions from the standpoint of personal experience. One caveat: I am a
dyed-in-the-wool Commander junkie now, and that colors my attitude. Don't
expect a perfectly objective reply ;-).

1.  Assuming I complete my ME complex certification in a Seneca. Is it
reasonable/safe for someone with my limited
    flying skills to jump to a Commander such as a (500A/B/S, 520 or a 560)
    Obviously each aircraft is different, I am asking generally.

I learned to fly a twin in my aircraft. I also got some time in a Baron, and
the Commander is far more predictable on one engine. To quote Chris, the
quality of instruction and the effort you put into understanding your
Commander is far more important than the vehicle itself. Although I'm sure
it would have been beneficial for me to have had some experience before
jumping into a complex twin, I also feel that I had no bad habits to
unlearn, and I was geared from the start to gain mastery of only one
aircraft--MINE. Also, I was trained by Sunwest Aviation in Tucson, AZ. They
have an "insurance certified" Twin Commander training program that also
helped with my insurance woes. The instructors there have about 11,000 hours
of Commander time among them and have an intimate understanding of Aero
Commander systems & procedures. I credit them with my proficiency. I visit
twice per year for recurrent training.

2.  Is there a minimum number of hours (translate: experience level) that
one might recommend before learning to fly Commanders?

I'm definitely not qualified to answer this! Subjectively though, it was a
bit intimidating to jump into such a large, powerful machine at first, and
it was 3 or 4 days of constant flying with the instructor before I started
to feel comfortable with the dimensions & speed of a Commander. Now, I feel
so at home in my plane I can't remember what it was like to be intimidated
by such an intelligently designed, comfortable, dependable aircraft.

3.  I have read that the Commanders "fly like a big 172", and also, that
"twin-commanders are complex and difficult birds"
    I am interested in your opinions on these quotes.

Personally I feel that the "complex and difficult" part is a misnomer, given
to the airplane by people who failed to properly maintain the aircraft. It
has extremely robust, redundant systems reminiscent of those on much larger
aircraft (like WWII bombers). Consequently, the occasional system failures I
have had in flight have all turned out to be non-events. But I work hard at
maintaining the aircraft in tip-top shape. Which is expensive. People who
don't spend the money on maintenance and then end up spouting hydraulic
fluid like a lawn sprinkler when they start the engines are quick to label
them troublesome beasts. Like anything else, an ounce of prevention is worth
a pound of cure.

It does indeed fly like a big 172. At an airport with large jet operations &
long runways, I can fly the plane on like an airliner at 110 knots and roll
out on a hi-speed taxiway just like the big boys....but I can also set her
down light as a feather in nearly a full stall at 63 knots and get a
complete stop in 900 feet....with no bad habits or unpredictability on the
part of the airplane. It is super stable in slow flight, and all the flight
maneuvers you did for your SE rating are no more difficult in the Commander.
And when you're in turbulence, it's *better* than any Cessna!

4.  Setting aside questions like operating costs (a topic of another email).
Is a complex twin like the Commander a good
    "first" aircraft, or would I be wiser to buy an single, build
experience, and hold the dream for later?

The only thing I know for sure is that there is no better *twin* to have as
a first aircraft. Name another where Vmc is below stall speed (not that it
matters, I've done several single-engine stalls with no problem), can carry
anything you can squeeze into it, is nearly impossible to mismanage fuel on,
and has a 99% dispatch reliability rating. This aircraft has allowed me to
plan trips far in advance, because it's never failed to launch. With a
little attention to the maintenance, you will discover that
things...just...don't...break on these airplanes.

Again, to paraphrase Chris, being aware of your own limitations is far more
important. I applied a great amount of effort to making sure that I did NOT
bite off more than I could chew. I planned my flight profiles very carefully
based on my experience and my instruction. I learned to handle the aircraft
at a slow enough pace so that I was fully confident of every procedure
before it could conceivably become a reality. I also devote much time to
maintaining the aircraft. I spend a lot of time with Morris learning the
systems and participating in repairs, so that I might have an intimate
enough understanding of the airplane to get an additional 2-second jump on
an emergency in flight. And I make a great effort to stay sharp on all my
emergency procedures. I believe in the value of recurrent training. And when
I got into mountain flying, and took off from Tahoe (9,500' density
altitude) at max gross from a short runway, that airplane kept me & the gang doing exactly what the POH said it could do. I'll be
commercial/instrument rated before February is out, to add more to my
skillset. And most importantly, I fly, fly, fly, every chance I get so that
I stay current & proficient.

Sorry for the long-winded reply. If you'd like to chat in person, you can
reach me at 408-482-4668.

Good luck,

/John Vormbaum

Anyway, I will just briefly state (in hopes of staving off any
such war here) that both of these engines are good.  Continental
has had problems with cracked cases and a rash of bad cranks,
but these seem to have been mostly resolved.  If you have one
of the older style 520 "light case" engines and a non-VAR crank,
you will automaticly get a new style case and new crank at no
additional charge with a factory reman.  That should pretty
much give you a reliable engine.
The various flavors of Lycoming 540s are pretty much bullet-
proof.  Lycoming has also had a few manufacturning blunders
including forgetting how to make an oil pump and piston pins.
These issues have also been resolved.  The 300HP twin-turboed
IO-540 on my Viking provided me with 2000 trouble-free hours
of service without ever removing a jug.  I opted for a custom
overhaul at 2000hrs out of guilt and the desire to trouble-
free operation and found no internal trauma at teardown.  I
am quite certain that my new engine will run another 2k.

Bottom line: take care of your engines, fly often, and keep
clean oil in 'em (I change every 20 hours).  Either engine
will provide good service if not abused.


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Re: Geared v Straight - A spirited discussion!
« Reply #1 on: October 10, 2015, 12:21:39 pm »
Awesome post.  I've never had a geared engine and with my new to me 680FP I now own 2.  I have been a bit concerned based on everyone (that doesn't have one's) opinion of how bad they are.  Hoping I find them as reliable as those here.

You can't win an argument with an ignorant person,  they'll just drag you down to their level and beat you with experience.