Hi Syd,
Absolutely correct. I stand corrected.
Thanks!
WRB
--
On Sep 11, 2009, at 21:17, Syd Cohen wrote:
WRB and Harry,
I think you both meant to say "1320 lb. gross," not 1340 lb. gross."
Syd
On Sep 11, 2009, at 9:05 PM, William R. Bayne wrote:
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unpublished.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: "[email protected]" <[email protected]>
To: [email protected]
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.
