GP940E 01/97
27.02.97
22
An ENL (Engine Noise Level) value of over 250 indicates engine running or the vibration of takeoff or landing.
Consistently lower ENL values indicate gliding flight.
B5
Calibration of Barograph Function.
The FR can be calibrated in an altitude chamber in the same way
as a drum barograph. After the calibration, the data is downloaded as if it was flight data (see B2.3 above) and
the calibration data file will then be analysed and a correction table produced of true against indicated altitudes.
This table can then be used to correct pressure altitudes which are recorded during flight performances and
which require correction for validation to IGC criteria. These include takeoff, start and landing altitudes for alti-
tude difference and for comparison with QNH readings, and low and high points on gain-of-height and altitude
claims. The maximum height tested by GFAC (Sep 96) was 50,000 ft.
----------------------------------------------
