User's Guide ______________________________________________________________________  
278 _________________________________________________________________ M211296EN-A 
QFE/QFF Pressure 
The reduced air pressure QFE (pressure at a certain level) or QFF 
(pressure at sea level) are calculated as follows: 
1
T
L
A
ePQF   
where 
T
1
  =  7996 + 0.0086 * L + 29.33 * T
A
 
L  =  Reduction level in meters 
T
A
 = 
Air temperature [C] 
P
A
  =  Atmospheric pressure [hPa] 
QF  =  Reduced pressure (QFE or QFF) [hPa] 
 
Table 114  Inputs for QFE/QFF Pressure Calculation 
Input Variable 
Air temperature (T
A
) TAAVG1M; see Table 4 on page 22 
Atmospheric pressure (P
A
) OFE  PAAVG1M; see Table 5 on page 23 
Atmospheric pressure (P
A
) QFF  QFEAVG1M; see Table 5 on page 23 
Reduction level (L) QFE  Station parameter 'pslevel' 
Reduction level (L) QFF  Station parameter 'altitude'