Hey Don: The way to determine what is required is to read the type
certificate/installation instructions. Item 110 of the type certificate states:
110. Engines
Continental C-85-12 or -12F
Engine limits for all operations: 2575 r.p.m. (85 hp.)
(Eligible with item 1(c), 3, 4, 6, 7, or 8 propeller only).
Eligible on model 415-CD; eligible on model 415-C provided the following
are accomplished:
(a) Modifications specified under item 106 for installation of C-75 engine.
(b) Wide elevator trim tab (1-3/8 in chord) installed per Erco dwg.
415-22031 or narrow trim tab (3/4 in. chord) installed per
Erco dwg. 415-22027 (or item 401).
Note: Conversion of continental C-75 engine to C-85 must be
accomplished in accordance with Continental Service Bulletin M47-16,
dated 6-7-48 and the oil sump dip stick recalibrated to indicate full when
So I think it is clear that the trim tab be installed. However, it
does not have to be the wide (1-3/8 in. chord) that is required when you
convert a C model to a D model.
Lynn Nelsen
In a message dated 8/28/2010 10:57:57 P.M. Eastern Daylight Time,
[email protected] writes:
This is very confusing to me. I have a C75 upgraded to C85. My plane came
with the extra oil tank and carb baffles NOT INSTALLED. I have been under
the impression I was not correct until I installed them (although it has
been flown for years with them in a box in the hangar. Am I reading this that
there is no requirement to add those baffles on my 415C model? I am also of
the belief that I must add a trim tab system to fully be in compliance with
the C85 conversion (again it has flown for years that way without the trim
tab, mine is an early model that came without a trim tab)
--- In [email protected]_ (mailto:[email protected])
, "Kevin" <kgass...@...> wrote:
>
> For the 1320 STC the aircraft must be in compliant with A-718 so
therefore no additional cooling baffles needed.
>
> Kevin1
>
>
>
> --- In [email protected]_
(mailto:[email protected]) , William R. Bayne <ercoguru@> wrote:
> >
> >
> > The question (as I interpret it) seems an important one inasmuch as
> > the answer essentially addresses the "airworthiness" of a given
> > Ercoupe, with or without said baffles. Always remember I'm NOT a
> > mechanic...I do have considerable engineering and legal experience
> > reading and interpreting applicable specifications necessary to the
> > supervision and inspection of installations by others.
> >
> > As previously stated here, there are NO special cooling baffles
> > involved with a 415-C, or 415-CD with a 75 hp engine.
> >
> > If one upgrades the original C-75 to C-85 spec. for operation at the
> > 1400 lb. gross wt. of the 415-D under Type Certificate 787, then the
> > extra cooling baffles around the oil tank shown in the Ercoupe Parts
> > Manual, Fig. 17, Items 13, 14 & 15 are required (as explained in the
> > description of these items on p. 23).
> >
> > Since the 1320 lb. STC was approved using data from the 415-D Model
> > under TC 787, logic would seem to dictate that flight operations at
> > the higher weight would require the extra cooling baffles that are
> > required on the 415-D when a C-85 is fitted.
> >
> > I seem to recall someone knowledgeable having previously commented
> > that there was no actual flight testing associated with the review
> > and approval of said STC. It may be that the actual wording of the
> > STC paperwork does not specifically require the installation of these
> > baffles (I don't have a copy for reference, but would appreciate a
> > copy if anyone has the time and the inclination ;<).
> >
> > It is likely demonstrable that at 1320 lbs. with "standard day"
> > conditions the extra baffles are not necessary to meet applicable
> > cooling criteria, but that's a potential financial mine field in
> > today's regulatory climate probably best not entered.
> >
> > Hope this helps,
> >
> > WRB
> >
> > --
> >
> >
> > On Aug 27, 2010, at 16:05, Ronin Sensei wrote:
> >
> > >
> > >
> > >
> > >
> > > Can anybody direct me to, or send me, a detailed diagram and
> > > instructions for installing the cooling baffles on a 1320 lb
> > > Coupe? (or a D model, since they are the same, I understand).
> > > This is driving my A&P crazy.
> > > Any help will be appreciated.
> > > Dave Winters
> >
>
