Hi Richard,
On 7/31/47 ERCO had ended production of the 415-CD. It would not be
until around Christmas that the next two airframes were completed...the
first 415-E Models, and March of '48 (when Fred Weick left ERCO) when
was production resumed after the transfer of the Ercoupe "package" to
Sanders.
Is there a Serial Number on the 337? 827.75 looks to me like the
"Empty Weight" of a CD with that radio installation.
Certification of the original Model 415, 415-C and 415-CD Ercoupe was
under CAA Civil Air Regulations 4a. Applicable structural requirements
were higher than the later CAR 3 applicable to the 415-D, E, G, etc.
Operating at the "light" 1260 lb. gross, limited aerobatics were
permitted.
Accordingly, when the 415-C Service Manual came out (dated January 1,
1947) ERCO expected the 415-C to be allowed to operate in the "new"
Normal Category at the higher 1400 lb. gross weight. This was printed
on p. 9, but asterisked as "Subject to CAA approval (which never came).
If you subtract the "Utility" useful load on this 337 from the "Normal"
useful load, the difference is 140 lbs. That corresponds exactly with
the 140 lb. difference between the 1260 lb. gross of the 415-C and the
later 415-D model which the CAA required of ERCO for 1400 lb. gross
operations.
It was a time of high expectations and uncertainty.
Best regards,
William R. Bayne
.____|-(o(-|____.
(Copyright 2010)
--
On Apr 5, 2010, at 19:56, Richard Wilkens wrote:
I have a question about Normal/Utility.
I have an old 337 dated 7/31/47 for a radio installed by Parks
Aircraft, one of the biggest Coupe dealers of the time. The aircraft
is 415-CD. On the front of the 337 they give the following W&B
information:
Empty Weight: 827.75
Useful Load: Normal 572.25
Utility 432.25
Could a CD have been both a Normal (at 1,400) and a Utility (1,260)?
The type certificate is “Pending.” It has not been approved at his
time.
This was done by a company that knew Coupes. Any ideas?
Richard
NC99904
