Hi David:
Unfortunately, my friend has no number recorded of the exact angle
of climb at the moment the engine began its RPM drop (in my previous
mail I wrote "perhaps nearly 40 deg" as a reference, and as a way to
say "as maximum"). That's why I had preferred to talk about steep or
very steep angle in all other mails. Apart from that, I wrote "The
pilot did not give the engine the opportunity to stop, so immediately
put the nose down ...". The plane was not ascending in such a steep
angle for a long while, surely it can't, it was a short while.
I add one more thing: Elevator travel up from Approved flight manual:
20 deg.
Thank you very much for your answer !
Best Regards
Daniel
From: David Winters <[email protected]>
To: Daniel Arditi <[email protected]>;
[email protected]
Sent: Wednesday, April 22, 2009 6:07:37 PM
Subject: RE: [ercoupe-tech] RPM Drop during Climb Out
A bit of math.
A 40 degree angle of climb is approximately what a U2 accomplishes on
take-off. So, at the end of a 5000 foot runway, he is about 1 mile
high.
For the Ercoupe to accomplish this at 60-70 mph would require a climb
rate of a bit under 5000 ft/minute.
Can't be done.
Now, I know the climb angle will not be the same as the nose angle,
but it for sure will not be enough different to bring these numbers
into line with Coupe performance capabilities.
In short, I cannot believe a coupe is maintaining any sort of climb in
a 40 degrees nose-up attitude.
Make sense?
Dave Winters
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From: [email protected]
[mailto:[email protected]] On Behalf Of Daniel Arditi
Sent: Wednesday, April 22, 2009 2:25 PM
To: [email protected]
Subject: Re: [ercoupe-tech] RPM Drop during Climb Out
Hi Harmut:
I did not make a conclusion yet, I am just trying to separate
things with some order, I mean, in a way, assigning priorities. I 100%
agree with you. We have to be cautious if we don't want to arrive to
a wrong conclusion. Anyway, before next flight, we must check
everything.
The point is that the RPM drop occurred during a very very steep angle
of climb-attack soon after take-off (perhaps nearly 40 deg). I don't
have the exact value as I was not there that day, I am just telling
what my friend told to me.
So:
Model: 415-CD (SN-4849)
What happened: Important RPM drop (not just as 10 or 20 RPM)
When: During take off (first time at about 450 ft AGL, second time at
about 350 ft AGL)
How steep: As I said, and based on what I was told, nearly 40 deg
How long: The pilot did not give the engine the opportunity to stop,
so immediately put the nose down and land.
Conditions: 17 Celsius, 60% humidity, 1016 Hpa. (approx. values)
Fuel: 100LL
Engine: 800 Hs. from last service
Carb.: Revised
Idle, on ground: run properly
Full throttle on ground: run properly
Carb.: Marvel MA-SPA / 10-4252 SN 4010081
Leaning mechanisms status: Really don't know. Have to ask.
Accidental lean by passenger: Discard (pilot alone)
Hope this extra information can help.
Nobody still told me what is the distance between fuel tank output and
carb. input (I sent a drawing in a previous mail and called that
distance "d"). I attached the picture here again.
Thank you very much for your attention.
Daniel
From: Hartmut Beil <[email protected]>
To: [email protected]; Techlist Ercoupe
<[email protected]>
Sent: Tuesday, April 21, 2009 6:05:01 AM
Subject: RE: [ercoupe-tech] RPM Drop during Climb Out
Daniel
Don't jump to conclusions that fast.
As Ed pointed ou, you need to be able to climb very, very steep
to experience a leaning effect to the carburetor strong enough that
the engine will quit. You are basically stalling the plane then big
time. I doubt that this happened.
To really help you, you need to be more elaborate about what happened
when. How steep did you climb for how long etc.
What about the weather conditions? humidity, temperature etc? What
fuel are you using?
How many hours are on the engine? for how many years?
As for now, I would rather point at a stuck valve that messes up the
mixture , not so much the carburetor. But cleaning the carburetor
might help in any case.
How is the engine running otherwise? In idle, at around 1000rpm etc.
With a C-90 engine ( I think you have a C-90) you should have a
Marvel- Schebler carburetor. Does the leaning mechanism work correctly
on that carb?
maybe when you fly with a passenger , the passenger accidentally
actuates the leaning mechanism and starves the engine.
There are too many possibilities.
We need more input from your side, otherwise you might be pointed into
the wrong direction, and not be solving the problem at all.
Hartmut
To: [email protected]
From: [email protected]
Date: Mon, 20 Apr 2009 18:17:55 -0700
Subject: Re: [ercoupe-tech] RPM Drop during Climb Out
Ed:
Fuel flow: Now clear enough to me.
You wrote: "Only if your plane is very light, flying solo, and the
weather is cold so the engine is extra powerful, is it possible to get
the nose so high that fuel does not flow properly to the engine. Not
all Ercoupes can get the nose this high. As soon as the nose is
lowered, power returns."
This is exactly what I was waiting to hear !!!!!!!!
It is hard to believe that this could happen, but we think that this
could be the reason why the power went down soon after take off, when
in a steep angle of climb (that was the case).
It is the first time I hear this, and I insist, it is hard to believe
to me that this could happen to a plane, but of course, physically
possible.
So, now talking about this issue, I attach a drawing I made, so if any
of you can tell me the distance showed in the graphic (I called
"d"). My friend's Erco Engine is a C90 and carburetor has been
changed, so, perhaps is something wrong with that distance.
Best regards, and thank you very much again for all of your help !!!
Daniel Arditi
Buenos Aires, Argentina
From: Ed Burkhead <e...@edburkhead. com>
To: Daniel Arditi <daniel_arditi@ yahoo.com>; ercoupe-tech@
yahoogroups. com
Sent: Monday, April 20, 2009 6:46:54 PM
Subject: RE: [ercoupe-tech] RPM Drop during Climb Out
Daniel Arditi wrote:
Although this explanation sounds very interesting to me, I still have
some doubts:
1.- I don't understand clearly the reason why the fail occurred with
2 people and not with one. Is it that with more weight to lift you need
more power and that extra power (with two people inside) has
exceeded the limit the fuel flow with the .030 could provide?
Daniel,
The number of people and full gross weight should not have anything to
do with loss of power. It is normal to take off and climb at full
power – always.
The fuel flow with the limiter is still many times what the engine can
use (maybe 5 times as much fuel as the engine can use).
2.- Has the take of angle of climb anything to do with this problem ?
Only if your plane is very light, flying solo, and the weather is cold
so the engine is extra powerful, is it possible to get the nose so
high that fuel does not flow properly to the engine. Not all Ercoupes
can get the nose this high. As soon as the nose is lowered, power
returns.
Ed
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