I am disapointed by the explanation of this question... The result to be given is a pressure altitude, and the explanation gave a result regarding to QNH...

According to the chart the minimum obstruction clearance altitude (MOCA) is 8500 ft. The meteorological data gives an outside air temperature of -20°C at FL 85. The QNH, given by a met. station at an elevation of 4000ft, is 1003 hPa. What is the minimum

this one only requires a temperature correction ?. MOCA 8500ft is QNH ?

Temperature correction ?. 4% per 10° deviation from ISA

ISA at FL85 = -2° C, so temperature condition is ?ISA-18 °C?

Correction 7.2% from 8500ft to DATUM (4000ft).

Datum in this instance is our met station at 4000ft

7.2% x 4500 = 324ft

Is it plus or minus 324ft ? high to low careful go ? temp is low ?. +324ft

Answer 8824ft.

Is there something i did not understand?

According to the chart the minimum obstruction clearance altitude (MOCA) is 8500 ft. The meteorological data gives an outside air temperature of -20°C at FL 85. The QNH, given by a met. station at an elevation of 4000ft, is 1003 hPa. What is the minimum

__pressure altitude__which should be flown according to the given MOCA?this one only requires a temperature correction ?. MOCA 8500ft is QNH ?

Temperature correction ?. 4% per 10° deviation from ISA

ISA at FL85 = -2° C, so temperature condition is ?ISA-18 °C?

Correction 7.2% from 8500ft to DATUM (4000ft).

Datum in this instance is our met station at 4000ft

7.2% x 4500 = 324ft

Is it plus or minus 324ft ? high to low careful go ? temp is low ?. +324ft

Answer 8824ft.

Is there something i did not understand?

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