Engineering and Research Corporation Ercoupe 415-C, Руководство по эксплуатации для пилотов, Страница: 8 / 27

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density found at sea level when the barometer reads 29.92 inches
of mercury and the temperature is 59⁰ F.
The true air speed may be found with satisfactory accuracy by
adding to the indicated air speed, 1 percent of itself for every 10⁰
above 59⁰ (or subtracting likewise for below)
For example, if the temperature is 89⁰ and the indicated air speed
is 95 MPH, 1 per cent of it is .95 MPH and for 3 percent add 2.85
MPH, making the true air speed 97.85 MPH
For altitudes up to 10,000 feet, at 59⁰, add 1 per cent for every 500
ft. At 6000 feet add to this indicated air speed of 95 MPH, 12 x . 95
or 11.40 MPH, making 106.40 MPH. Since the temperature at 6000
feet is 89⁰ the 2.85 MPH correction should also be added, making
109.25 MPH
There is also a correction for a change in barometric pressure. If
the barometer at sea level is down 0.6” below the normal 29.92,
another 1 percent is added. Therefore, if the barometer reads 29.62
at sea level, add .5 x
. 95 or .47 MPH to the 109.25 MPH, making
109.72 MPH the true airspeed.
The carburetor mixture control is operated by means of a push-pull
knob on the instrument panel near the throttle. At altitudes above
5000 ft, the decreased density of the air may cause the mixture to
become too rich for best power. This may be investigated by
moving the mixture control from the full-rich position while
checking the constant load RPM. If the RPM does not increase as
the mixture is made leaner, the control should be returned to the
full-rich position. For average operation below 5000 feet altitude,
the carburetor should be left in the full-rich position. When at part
throttle, the fuel consumption may be improved by leaning the
mixture, but in no case should the control be moved far enough to
decrease the engine RPM. The control should always be moved
back to full-rich before any change in throttle setting
While cruising, the carburetor air heater is controlled by a
push-pull knob on the instrument panel near the throttle. The
engine should be operated with cold air at all times, except when