This is an area of Ercoupe history where many have not been as specific
as is necessary to be absolutely correct.
Every Ercoupe historian stands on the shoulders of those who wrote
before and sees more clearly for it. But every enthusiast that would
purport to speak knowledgeably has the obligation to "get it right"
when they write. At this late date there is very little about the
Ercoupe that remains genuinely unknown or that should be confusing.
Unfortunately a lot of new information is as of yet unpublished.
Some time ago I decided that it would be better "for the fleet" to
share some of what I have learned before I publish. In some cases it
is because it will, in my opinion, result in greater safety. In other
cases this is because published information is so wrong.
While everyone is entitled to their own opinion(s), I believe each of
us has an obligation to try our best not to confuse; and by that I mean
that opinion should be clearly differentiated from speculation, and
speculation similarly differentiated from supportable fact.
When I speak of the over 100 415-Cs that were factory-converted to
415-CD specifications, I speak factually. I have ERCO letter copies
containing serial numbers, and have personally seen and photographed
such dataplates. These materials will be published in the future.
Individuals may certainly choose until then to dismiss my assertions as
speculation. To such extent as they refuse to give reasonable
consideration to what I say it is their credibility that will suffer in
the end. My research will be published someday whether or not I manage
to do it myself, and facts I cite can be proven by anyone and everyone
capable of visiting my sources. It is much harder to discover facts
few, if any, know than to verify them later and independently.
Comments interspersed below.
WRB
--
On Sep 11, 2009, at 17:40, Harry L. Francis wrote:
Roberto and the Group,
First, let's try to define the models, and then you will see the
qualifications:
The Ercoupe 415 s/n 1, was first certified with the ERCO IL-116, 65
hp 4 cyl, Inverted air cooled, engine, and simply specified as Model
415.
Before any were sold, Continental made the A-65-8 engine available at
about a $500 saving per engine, thus making the 415C (for
Continental). All Ercoupes have been sold with versions of the
Continental engine..
When CAA made new specifications for aircraft - (Normal and Utility
Catagory), this allowed for a higher gross weight
allowance......making the 415C elgible for a higher gross weight......
Thus, was born the 415D with a higher gross weight (1400lbs).
Well....sort of. When the CAA updated their previous standards
applicable to the certification of light aircraft, several things
happened.
Whereas before there had been no category of aircraft certified as
"incapable of spinning", there had been a level playing field. ERCO
and Fred Weick surprised everyone with their Ercoupe design, which
represented a huge leap forward in light plane design. When prewar
production ended due to materials unavailability, there were
approximately 600 airframes "on order". Everyone's attention was
quickly elsewhere "for the duration", but a number of manufacturers and
other "powers that be" were extremely concerned that ERCO might
dominate the postwar light plane market.
It may be impossible to discover precisely where and when the idea came
to the CAA to update their design standards, but at some point there
was incorporated into them a set of test standards applied only to
aircraft certified as "incapable of spinning" (i.e. the Ercoupe).
These were clearly far in excess of standards applicable to other light
aircraft, and were so draconian in detail as to discourage further
development. It was these test standards that proved an Ercoupe was as
spinproof with 18º up elevator movement as with 13º up movement, but
then "approved" only four degrees less than that. 13º - 4º = the
infamous 9º.
I have an Ercoupe Service Manual with a date of January 1, 1947 as
signed by Service manager Ro. Sanders. It clearly shows that as of
that date ERCO expected that the CAA would approve all 415-C Ercoupes
produced under the older standards for the higher 1400 lb. gross
weight. We now know that didn't happen. The CAA insisted on testing
according to the grossly unfair new "rule", and the resulting
"approval" for their latest model was under an entirely new type
certificate and elevator movement was limited to the entirely arbitrary
9º up movement.
Initially, many folks were not satisfied with the higher weight
aircraft, which required a higher approach speed than the 415C, due to
the limited elevator up travel of 9 degrees (C and CD models have 13
deg up); to prevent the coupe from potentially achieving a stall
attitude.
No. Only two 415-D models were sold. Those two purchasers and ERCO
were not satisfied with the reduction in landing flair capability
resulting from the reduction in available elevator "up" travel. What
to do? The production line had already switched over to producing the
"new" model, which had a revised instrument panel and improved fuel
tank plumbing allowing wing tank caps without vents.
The "solution was to apply for certification of the 415-CD model under
the original type certificate with the lower gross weight. Production
could continue. It was simply that both existing and new owners would
be denied the additional gross weight allowed under the new standards.
Owners of both 415-Ds produced had their aircraft modified to 415-CD
specification, and so, for some time, there were NO 415-D models
flying.
None of the above had anything whatsoever to do with preventing "...the
coupe from potentially achieving a stall attitude" other than in a
sense so abstract as to be ridiculous.
So, very shortly the factory incorporated the
modification/improvements that were made in the D model (such as a
stainless steel cover over the header tank, etc) but maintained the
elevator up travel in the C model, and certified the revised coupe at
the C model GW of 1260 #. This model was called the CD model.
The factory didn't have to do a thing. This was what was rolling off
the line already. They just needed paperwork allowing them to rig the
airframes as before and sell them. Yes, they did then sell those
airframes identical in every respect to the D model as their 415-CD.
There is no such thing as a C/D model, tho many people call a C model
thas been converted to D specs ( higher GW, etc.) a C/D model.
Those people, as you say, would be simply wrong.
The conversion requires inspection and approval by a FAA field
inspector, and issuance of a new Airworthiness Certificate. There are
over 100 415C models registered that have been modified to D specs. I
think many have been inspected and approved, and many that have been
modified with a 337, but actually still have a 415C Standard
Airworthiness Certificate.
As I have said before, over 100 415-C models in dealer hands and unsold
when the 415-CD was announced were of no interest whatsoever to a
purchaser who wanted the "latest and greatest" from the factory. ERCO
understood and factory modified these airframes in the field. After
modification they were identical to the 415-D. Physically they could
become a 415-D merely by re-rigging to 9º up elevator. Paperwork was
another matter, in particular since a new name plate showing they now
operated under Type Certificate 787, and a new Airworthiness
Certificate would seem to be necessary at a minimum. In any event, a
majority of 415-C serialed airframes that later became 415-D models per
FAA records were ones the factory had upgraded from 415-C to 415-CD
before sale.
(Some folks understand the Model of an Aircraft can only be changed by
the manufacturer; but that an aircraft can be modified to the later
specs, by simply following the Manufacture's Service Memorandums, with
the use of a 337. I would call this change as a C model modified to D
model Specs....
The factory apparently agreed. The 415-Cs it Modified to 415-CD
specification received ERCO plates stating they were "modified" as
415-CD and had the date of that modification thereon stamped. Skyport
may sell these plates for the conversion to 415-D. If not, they did at
one time.
Here-in lies the problem:
The LSA rules specifically state that an aircraft that has been
operated at a legal GW higher than the LSA GW specs of 1340 pounds,
does not qualify for certification as a LSA.
Of course lots of discussion enters here ...just what does the rule
really say..... and lots of arguments.
The rule says what it says. Lots of opinions. Arguments are optional
;<)
There is NO Difference between the C/CD/ D model Ercoupes....except
simple modifications to throttle, carb heat, and trim control
operation, minor changes to the landing gear, Gross Weight difference,
and *stainless /steel over the header tank in the D and CD models..
I believe you meant minor changes to the main gear oleo orifices above.
Obviously the "up" elevator movement rigging was a difference deemed
of substantial impact to comparative landing qualities. In addition,
the splitting of the header tank overflow line to go to both wing tanks
was the original change to unvented wing tank caps. This is obvious by
comparing the fuel diagrams of the Ercoupe Instruction Manual and the
FAA-Approved Flight Manual for the 415-D. The gross weight difference
of 140 lbs. more for the 415-D made huge operational differences as to
Service Ceiling, takeoff and landing distances, etc. that should not be
so lightly dismissed.
*This regulatory safety requirement was missed in the original
Certification of the C model with the Continental engine, because the
IL-116 engine cowling stopped at the S/S firewall, and the change to
the Continental engine required larger cowling that went past the
firewall.
Strictly speaking, the Continental cowling ignored the position and
shape of the original firewall, covering parts of the aluminum fuselage
that would now be vulnerable in case of an engine compartment fire.
The D model up elevator limit is set at 9 deg to supposedly prevent
the heavier GW coupe from approaching a stall attitude at full
throttle climb.
This is unsubstantiated speculation. The 415-C is capable of full
throttle climb attitudes that cannot be sustained if power is lost.
Put more weight in that same airframe and the same engine simply cannot
get the aircraft's nose up as high.
The 1260# GW of the C and the CD model elevator travel is 13 deg up.
There is now an STC for raising the C and CD model GW to 1340 # GW.
Interestingly this STC requires limiting the elevator up travel to the
D specs of 9 degrees..
John Cooper has explained that the FAA was willing to accept the
testing ERCO had done for the 415-D model for the 1340# gross.
I think we will eventually see the D model @ 1400 GW (maybe even 1450
GW, which would include the later Ercoupe models, Forney, Alon, ertc.,
all approved as LSA; ,,, tho the LSA industry will fight it to the
end. Of course this would also lead to the Cessna 150, and other light
aircraft to be approved as LSA.
As you probably know, the creation of the LSA aircraft designation was
simply to encourage the development of light, low cost, new
airplanes.....and were develped with specifications set by the
manufactures with the use of ASTM consensus type development.
Hopefully , we will see the inclusion of the D, E, F, G, Ercoupes
into the LSA catagory. Interestingly the H model qualifies, except
those that now weigh more because the owners added Battery, Starter
and Generator.
Just my opinion....
Fly Safe - Have Fun
Harry Francis
N93530
From: "r3...@warwick.net" <r3...@warwick.net>
To: ercoupe-tech@yahoogroups.com
Sent: Friday, September 11, 2009 11:35:03 AM
Subject: [ercoupe-tech] 415-C/D - When it is an LSA and when it is not?
As subject says.
I've seen ads for 415's C/D including lines such as:
"LSA",
"not an LSA",
"qualifies as LSA",
"light sport eligible",
"light sport status dubious",
"previous owner bought it as LSA, but it was not"
"its a 415-CD, selling as a D model" (??)
What are the criteria for determining if a C/D is a LSA or not?
Thanks,
Roberto Waltman.
