QNH is the atm pressure at S.L. (Question Nil Height - what is the atm pressure at nil height i.e. sea level)
1) Set QNH as the reference pressure - altimeter reads height above sea level. E.g. QNH of the day is 1022. We set 1022 in the subscale then the altimeter will read the height of the aircraft above the sea. This is called ALTITUDE.
QFE is the atm pressure at a particular field. FE is Field Elevation.
2) Set QFE then the altimeter will read the height above the field. How do we do that? If the hands of the altimeter are forced to read ZERO while the aeroplane is on the ground the reference pressure will be QFE and the altimeter will read height above the field. This is zero as the a/c is on the ground.
3) If the QNH is again set while the a/c is on the ground at this field the altimeter will once again read the height above the sea. In this case it is called ELEVATION.
1) Set QNH as the reference pressure - altimeter reads height above sea level. E.g. QNH of the day is 1022. We set 1022 in the subscale then the altimeter will read the height of the aircraft above the sea. This is called ALTITUDE.
QFE is the atm pressure at a particular field. FE is Field Elevation.
2) Set QFE then the altimeter will read the height above the field. How do we do that? If the hands of the altimeter are forced to read ZERO while the aeroplane is on the ground the reference pressure will be QFE and the altimeter will read height above the field. This is zero as the a/c is on the ground.
3) If the QNH is again set while the a/c is on the ground at this field the altimeter will once again read the height above the sea. In this case it is called ELEVATION.
No comments:
Post a Comment