Dave wrote:

> 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.

 

 

Dave,

 

You’re right.  40° nose up is pretty unlikely (except for a zoom climb).

 

Now, let’s test Mrs. Grooms’s teaching of trigonometry, 50 years ago:

 

At 17°C (62°F) and solo, I bet he wouldn’t be getting much better than 600
fpm at 60 mph.  That would be about a 6½° climb.

 

For discussion, let’s say the Coupe wing stalls at a 23° angle of attack.
So, 23° + 6.5° = about 30°.

 

I’m making a WAG (wild a** guess) that there’s about a meter (39 inches)
front-to-rear from the tank fuel outlet forward to the carburetor inlet.  At
that distance, a 30° nose up would put them level at anything less than
about 58 cm (22-23 inches) vertical separation.

 

I don’t think there is that much vertical separation, “d” on Daniel’s
diagram.

 

A correctly rigged Coupe can’t get to the stall angle of attack.  The 13°
elevator up travel limitation prevents this.  Ditto the elevator up travel
limits for the other models.

 

But, even in a plane with only 9° elevator up travel, flying solo I managed
to get the nose up so steep on a cold winter day that I got to the engine
starved condition.  It wasn’t 40° but it was enough.

 

Here’s a proposed test.  The wisdom of doing this test belongs to the pilot.

 

On a cold day, flying solo, take off and do a moderate angle climb to
altitude – at least 3,000’ above the airport (1,000m or more).  Be near
enough to the airport to guarantee you can glide there if you lose power and
don’t get it back.  Then, very slowly pull up into a full power climb and
see if you get the same temporary loss of power.  (The moment the nose
drops, the power should come back.)

 

When doing tests like this, it’s very good to have a good place to land
right under you and to be well practiced in getting there.  JMHO

 

Ed

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