1 Introduction
1.1 The Altimeter setting procedures in use generally conform to those contained in ICAO Doc 8168, Volume 1 Part 6 and are given in full below.
1.2 Transition altitudes are given on the instrument approach charts.
1.3 QNH reports and temperature information for use in determining adequate terrain clearance are provided in MET broadcasts, and are available on request from air traffic services units;
QNH values are given in hectopascals(hpa).
2 Basic altimeter setting procedures
2.1 General
2.1.1 The Transition Altitude is fixed at 13 000 FT
AMSL and the Transition Level is fixed at FL 150 within Doha
FIR.
2.1.2 Vertical displacement of aircraft at or below the Transition Altitude is expressed in terms of altitude. Vertical displacement of aircraft at or above the Transition Level is expressed in terms of Flight Levels. While an aircraft is passing through the Transition Layer, vertical displacement is expressed as altitude when descending, and as Flight Levels when climbing.
2.1.3 Flight Level Zero is located at the atmospheric pressure level of 1013.2 hPa (29.92"). Consecutive Flight Levels are separated by a pressure interval corresponding to 500 FT in the Standard Atmosphere below FL 290, and by a pressure interval corresponding to 1 000 FT above FL 290.
2.1.4 Simultaneous flight at both the Transitional Altitude and the Transition Level is permissible as a minimum of 1 000 FT separation exists between the two layers; however, level flight within the Transition Layers is not permitted.
2.2 Take-off and climb
2.2.1 A
QNH altimeter setting is made available to aircraft in the routine take-off and climb instructions.
2.2.2 Vertical displacement of aircraft during climb is controlled by reference to altitudes until reaching the Transition Altitude, above which vertical displacement is controlled by reference to Flight Levels.
2.2.3 In this context, the word
“controlled” is used in composite sense in that a pilot will wish to fly his aircraft at predetermined Flight Levels or altitudes, and
ATS will wish to advise the pilot of the availability of Flight Levels and altitudes. Both are concerned with the vertical position of aircraft.
2.3 Vertical separation - en route
2.3.1 Aircraft shall be flown En-route at Flight Levels at all times when above 13 000 FT AMSL.
2.3.2 When complying with the semi-circular system of cruising levels of Annex 2, an aircraft shall be flown at Flight Levels or Flight Altitudes corresponding to the magnetic track as shown in the following table:
| Magnetic Track | 000˚ - 179˚ | 180˚ - 359˚ |
|---|
| Flight Rules | IFR | VFR | IFR | VFR |
|---|
| Flight Altitudes | | 1 500 | 2 000 | 2 500 |
| 3 000 | 3 500 | 4 000 | 4 500 |
| 5 000 | 5 500 | 6 000 | 6 500 |
| Up to 13 000 | Up to 11 500 | Up to 12 000 | Up to 12 500 |
| Flight Levels | 150 | | 160 | |
| 170 | | 180 | |
| 190 | | 200 | |
| Up to 290 | | Up to 280 | |
| 310 | | 300 | |
| 330 | | 320 | |
| 350 | | 340 | |
| 370 | | 360 | |
| 390 | | 380 | |
| etc | | etc | |
2.4 Approach and landing
2.4.1 A
QNH altimeter setting is made available in the routine approach and landing instructions.
2.4.2 Vertical displacement of aircraft during approach is controlled by reference to Flight Levelsuntil reaching the Transition Level, below which vertical displacement is controlled by reference to altitudes.
Note: This does not preclude a pilot from using a QFE setting for terrain clearance purposes during the final approach to the runway.
2.5 Missed approach
The relevant portions of 2.1 and 2.2 shall be applied to the case of a missed approach.
3 Altimeter pressure setting within QATAR Airspace
3.1 All aircraft operating within DOHA
FIR and below FL 150 are required to use
DOHA QNH during climb and descend phase.
3.2 All
VFR traffic operating outside controlled airspace within Qatar airspace, should use
DOHA QNH.