Professionally built?

In a previous article, Orval Fairbairn said:
What we found (and corrected):

1. The oil cooler had insufficient airflow (both in and out). Remember
-- any cooling MUST provide an exit path for the air, as well as an
entry path. This installaltion had neither.

2. There was no blockage of cooling air in the nose bowl behind the
spinner, allowing air to exit behind the spinner. We installed the
appropriate baffles and seals there.

[etc]

Ok, this is where I get confused. I'm not a builder (yet). Don't the
plans or kit instructions tell you how to do all this? Do people diverge
that much from the plans, and if so, why?


--
Paul Tomblin http://blog.xcski.com/
Microsoft: bringing the world to your desktop -- and your desktop to
the world.
-- Peter Gutmann

Paul Tomblin wrote:


Ok, this is where I get confused. I'm not a builder (yet). Don't the
plans or kit instructions tell you how to do all this? Do people
diverge that much from the plans, and if so, why?

On many if not most kits the FWF instructions is not as nearly as complete
as the airframe instructions/plans. One reason for this is simple, The kit
maker also has little to do with the engine used in a lot of planes. For
example in the Zenith 601XL there are people that have installed multiple
flavors of Conts & Lycs, and Rotaxs, Jabirus, Subaru's, Corvairs, Suzukis,
and even Harley Davidsons.

On Nov 28, 7:40 am, Ron Natalie wrote:

The words PROFESSIONAL and AMATEUR are not mutually exclusive.
Get a dictionary.

Ok, I did.

You're right, someone could be an amateur as in experienced while
doing something for hire as opposed to doing it for personal
achievement and satisfaction. For home builts planes, I'm sure it is
"buyer beware" anyway.

"Orval Fairbairn" wrote in message
news
The "professionally built" term really doesn't amount to a hill of
beans. A friend here bought a Harmon Rocket that an A&P built. The metal
work was good, but the engine installation was very poor. I coined the
term "flyable but not airworthy" to describe the plane as purchased.

He could not maintain cruise power in vevel flight without overtemping
the oil. Our "Spruce Creek Skunk Works" took on the job of sorting it
out.

What we found (and corrected):

1. The oil cooler had insufficient airflow (both in and out). Remember
-- any cooling MUST provide an exit path for the air, as well as an
entry path. This installaltion had neither.

2. There was no blockage of cooling air in the nose bowl behind the
spinner, allowing air to exit behind the spinner. We installed the
appropriate baffles and seals there.

3. The air entering the cowling inlets passed over a sharp lip behind
the inlets. We added some internal fairing to the inlets.

4. Baffle seals were poorly thought out, allowing air to leak out the
top of the baffles, rather than passing over the cylinder fins.

5. Exhaust pipes were cantilevered, creating the opportunity for fatigue
failure. We added some support to reduce stress there.

6. The owner had the pipes ceramic coated, both inside and out, to
reduce heat transfer into the engine compartment. IMHO, it is more
important to coat the INSIDE of an exhaust pipe than the outside -- to
reduce heat transfer into the metal.

Result: The plane runs cool and FAST!

Very good example Orval. The phrase might mean a lot or it could mean
nothing. Based on the rules for constructing amateur built aircraft, it
"certifies" absolutely nothing.

In article ,
(Paul Tomblin) wrote:

In a previous article, Orval Fairbairn said:
What we found (and corrected):

1. The oil cooler had insufficient airflow (both in and out). Remember
-- any cooling MUST provide an exit path for the air, as well as an
entry path. This installaltion had neither.

2. There was no blockage of cooling air in the nose bowl behind the
spinner, allowing air to exit behind the spinner. We installed the
appropriate baffles and seals there.

[etc]

Ok, this is where I get confused. I'm not a builder (yet). Don't the
plans or kit instructions tell you how to do all this? Do people diverge
that much from the plans, and if so, why?

As "gig601builder" pointed out, a lot of plans are sketchy, at best, FWF.

That said, there are some decent books out there on FWF installations,
plus the exercise of common sense.

The biggest mistakes relate to airflow management, as on my friend's
plane.

A few basic principles:

1. Air must have a path out, as well as in. I have seen oil coolers
mounted with only 1/2 inch clearance between firewall and the aft face
of the cooler. No matter how much air you blow at the front side, it
cannot escape the back.

2. Use all of the air that comes in for cooling. Make sure that baffles
and their seals fit tight and that there are no gaps on their periphery.

3. You need blast tubes on the mags and alternator, as well as the oil
cooler.

4. Air inside the cowl will seek the lowest pressure areas to exit. A
common place is the front of the cowl, behind the spinner. That air
creates unnecessary drag and doe no cooling work. Baffle that area and
force the air past the cylinders, oil cooler, etc.

5. Exhaust pipes are an excellent heat source inside the bottom of the
cowl. You need some airflow there.

6. The more eyes that see your plane before it flies, the better. It is
far better to discover your errors (remember -- everybody makes some) on
the ground than to have them discover YOU in flight!

7. Get active with your local EAA Chapter and get to know the wise ones
-- they can save you a lot of grief!

Ron Natalie schreef:

The words PROFESSIONAL and AMATEUR are not mutually exclusive.
Get a dictionary.

Sorry, but as non-native English speaker I am confused here.
To my poor bit of learning, the meanings a
-) professional: mainly for profit, some fun not excluded
-) amateur: mainly for fun, some profit not excluded.
I don't have a dictionary handy - what does yours say?

The word "professionally" can be pretty vague. When I build my second
RV-4, I will sell it in Trade A Plane as "Professionally Built" since I
will be a "pro" at it having built one previously.

Scott
http://corbenflyer.tripod.com/
Gotta Fly or Gonna Die
Building RV-4 (Super Slow Build Version)

Bob Kuykendall wrote:
On Nov 27, 12:32 pm, es330td wrote:

I searched controller.com for lancair and found an entry that says
"Professionally built." Now I know that a homebuilt owner does not
have to build the entire thing themself but I thought it still had to
be an amateur undertaking. How does this pass muster with the FAA?


"Professionally Built" isn't a problem for Experimental aircraft. Many
aircraft were so built and subequently issued Experimental Racing and
Experimental Exhibition special airworthiness certificates.

However, it can be a big problem for an aircraft issued an
Experimental Amateur-Built special airworthiness certificate. The
rules are pretty clear that the major part of such aircraft are to be
constructed by folks who undertook the work solely for the purposes of
education and entertainment, that is, without money changing hands.
The word "Professional" implies here, as it does in the sports world,
financial transactions that likely violate the spirit if not the
letter of the Amateur-Built rules.

In at least one prior case, the FAA has moved a non-"51% rule"
aircraft out of Amateur-Built and into Racing or Exhibition. While
this is a relative non-issue for a glider or a single-seat acro
airplane, the additional operating limitations and Program Letter
requirements can put a huge onerous kink in your plans for a four-seat
cruiser.

Checking the controller.com site, I find not one but three Lancairs
that claim "professional construction," and at least one of those
lists a corporate entity as the manufacturer. Hopefully it's a non-
profit corporation...

I'm thinking that the sellers might be folks who haven't observed that
the FAA seems to have been cracking down on hired gunmanship, and that
they seem to be using sport aviation publications and circulars to do
it.

Thanks, Bob K.

--

In article ,
jan olieslagers wrote:

Ron Natalie schreef:

The words PROFESSIONAL and AMATEUR are not mutually exclusive.
Get a dictionary.

Sorry, but as non-native English speaker I am confused here.
To my poor bit of learning, the meanings a
-) professional: mainly for profit, some fun not excluded

Close enough. The job/work implication is the important part.

Notice that it doesn't necessarily preclude enjoying that work.

-) amateur: mainly for fun, some profit not excluded.
I don't have a dictionary handy - what does yours say?

Amateur literally derives from "lover of" something. You might get some
payback, but the love of the doing is the main point, and you'd probably
continue doing the thing with no received income.

jan olieslagers wrote:
Ron Natalie schreef:

The words PROFESSIONAL and AMATEUR are not mutually exclusive.
Get a dictionary.

Sorry, but as non-native English speaker I am confused here.
To my poor bit of learning, the meanings a
-) professional: mainly for profit, some fun not excluded
-) amateur: mainly for fun, some profit not excluded.
I don't have a dictionary handy - what does yours say?


The 4th definition of Professional in my dictionary.


4. Having or showing great skill; expert: a professional repair job.

Scott wrote:
The word "professionally" can be pretty vague. When I build my second
RV-4, I will sell it in Trade A Plane as "Professionally Built" since
I will be a "pro" at it having built one previously.


I don't know if I'd do that. It seems that it should be just a matter of
time until somebody at FAA get's a hair up their ass and sends down a memo
to all the FSDOs to investigate all such claims. Not that you would be in
violation of the law but why stir the pot?