----[Please read http://ercoupers.com/disclaimer.htm before following any advice in this forum.]----
Hi Tim,
Ercoupe Service Memorandum 59A is clear as mud on this subject.
When rudder pedals are installed in a 415-C or CD (with the full 13º up
elevator available), oblong placard 415-51077 or round plastic plate
415-51143 (each originally stating "THIS AIRPLANE CHARACTERISTICALLY
INCAPABLE OF SPINNING") are changed to read "INTENTIONAL SPINS
PROHIBITED". This says to me that under certain circumstances these
rudder-pedal coupes can spin!
It goes on to say that "Models D, E and G do not require any additional
placards for they have one stating, "THIS AIRPLANE CHARACTERISTICALLY
INCAPABLE OF SPINNING--NO ACROBATIC MANEUVERS ARE APPROVED--THIS
AIRPLANE MUST BE OPERATED IN COMPLIANCE WITH THE APPROVED OPERATING
LIMITATIONS."
You are unlikely to make a 415-D stall at 1400 lbs. with only 9º up
elevator available. That can NOT be said for the 'E' and 'G', so I
fail to see why the same change in wording was not considered
appropriate. What follows is not nearly as brief and clear.
The Approved Airplane Flight Manual for the 'E' and 'G' Models says, p.
6, "Low Speed Warning Cushion:
A signal is provided to let the pilot know when he is in the
region of
low speeds below that required in ordinary flight.
When he is starting an approach to a landing, as he reduces the
airspeed by gradually pulling back on the control wheel,
he feels a cushion resisting further rearward travel at about 60
mph.
At this point there is sufficient speed margin above
minimum speed to enable him to flare off the glide path for a
smooth
landing under average conditions. The control wheel
should not be pulled back through this cushion of additional force
until the airplane is within a few feet from the ground
and ready for the final leveling out of the glide path for gentle
contact."
Ercoupe Service Memorandum 35A states that "Power off minimum airspeed
is 60 MPH", while the above infers that "minimum speed" is reached
AFTER pulling the control wheel fully through the "low speed warning
cushion". So it appears there exists the "in-flight" minimum speed of
60 mph, and some "Landing" (ONLY) minimum speed (unspecified, but
probably 45-50 mph) with the control wheel all the way back through the
warning cushion.
With or without rudder pedals, the factory did not sanction the use of
the additional elevator authority of the split elevator for in-flight
stalls! Anyone (mis) using this additional elevator authority to
intentionally stall (or whip-stall) and cross-control successfully into
a spin immediately becomes an unauthorized and unpaid test pilot of
questionable intelligence. Our small rudders are of reduced
effectiveness by design. When one rudder moves out 22º and the other
moves in only 3º, rudder movement is only 57% effective (as compared
to having 22º movement available both ways)!
The SeaCoupe testing Edo floats needed additional elevator (to get
floats off the water) and rudder movement (water rudders). This made
it spinnable, so the CAA insisted it be spin tested. The aircraft was
destroyed after entering an uncontrollable spin.
Regards,
William R. Bayne
<____|-(o)-|____>
(Copyright 2004)
--
On Nov 24, 2004, at 8:28 PM, Tim and Martha Briggs wrote:
>
> Ercoupers:
>
> (I have rudder pedals)-...I have yet try stalling my Ercoupe while
> banked and skidding or slipping.
> Exploring that region of the flight envelope just doesn't appeal to
> me. Maybe sometime with a
> seasoned CFI or aerobatics pilot.
>
> Is there any info out there on how the Coupe behaves in a banked,
> uncoordinated stall??
>
> Thanks
>
> Tim
>
> Ercoupe 415G
> N94413
==========================================================================
====
To leave this forum go to: http://ercoupers.com/lists.htm
Search the archives on http://escribe.com/aviation/coupers/
<<attachment: winmail.dat>>
