ENR 1.7  Altimeter setting procedures

1.   Introduction

1.1  The altimeter setting procedures in use conform to those specified in ICAO Doc 8168 - PANS OPS/611 and Doc 4444 - PANS ATM/501.
1.2  The purpose of these procedures is to provide pilots with suitable pressure information which will assist them in maintaining adequate terrain clearance and also to ensure a safe standard of flight separation by the general use of altimeters set at 1013.2 hPa.

2.   Basic altimeter setting procedures

2.1   Flight levels
2.1.1  Flight level zero shall be located at the atmosphere pressure level of 1013.2 hPa. Consecutive flight levels shall be separated by a pressure interval corresponding to at least 500 FT (152.4 M) in the standard atmosphere.
2.1.2  Flight levels shall be numbered according to the table of cruising levels given in ENR 1.7.5 which indicates the corresponding height in the standard atmosphere in feet and the approximate equivalent height in metres.
2.2   Transition altitude
2.2.1  Transition altitude is the altitude at or below which the vertical position of an aircraft is controlled by reference to altitudes.
2.2.2  Transition altitude established for the Tirana FIR is 10000 FT.
2.3   Transition level
2.3.1  Transition level is the lowest flight level available for use above the transition altitude.
2.3.2  Transition level is located at least 300 M (1000 FT) above the transition altitude to permit the transition altitude and the transition level to be used concurrently in cruising flight, with vertical separation ensured.
2.3.3  The transition level is determined by reference to the following table:
Transition Level Reference Table
QNHTransition Level
≥1013 hPaFL 110
1012 – 978 hPaFL 120
≤ 977 hPaFL 130
2.3.4  Based on current and anticipated atmospheric pressure distribution, area control centre shall coordinate, when required, the lowest flight level to be used.
2.4   Transition layer
2.4.1  Transition layer is the airspace between the transition altitude and the transition level.
2.4.2  Level flight is not permitted within the transition layer, unless otherwise specified by the appropriate ATS authority.
2.5   Expression of vertical position of aircraft
2.5.1  For flights in the vicinity of aerodromes and within terminal control areas, the vertical position of aircraft shall be expressed in terms of altitudes at or below the transition altitude and in terms of flight levels at or above the transition level. While passing through the transition layer, vertical position shall be expressed in terms of flight levels when climbing and in terms of altitudes when descending.
2.5.2  For flights en-route, the vertical position of aircraft shall be expressed in terms of:
  1. flight levels at or above the lowest usable flight level; and
  2. altitudes below the lowest usable flight level.
2.6   Take-off and climb
2.6.1  The QNH altimeter setting shall be passed to an aircraft as part of the departure weather and data.
2.6.2  In addition, where the departure clearance requires an aircraft to maintain a specified altitude after departure, the QNH setting shall also be repeated as part of the departure clearance.
2.6.3  A QNH altimeter setting is included in the routine weather report transmitted to aircraft on initial contact.
2.6.4  Before taking off, one altimeter shall be set on the latest QNH altimeter setting for the aerodrome.
2.6.5  During climb to, and while at the transition altitude, references to the vertical position of the aircraft in air-ground communications shall be expressed in terms of altitudes.
2.6.6  On climbing through the transition altitude, the reference for the vertical position of the aircraft shall be changed from altitudes (QNH) to flight levels (1013.2 hPa), and thereafter the vertical position shall be expressed in terms of flight levels.
2.7   En-route
2.7.1  During en-route flight at or below the transition altitude, an aircraft shall be flown at altitudes. References to the vertical position of the aircraft in air-ground communications shall be expressed in terms of altitudes.
2.7.2  During en-route flight at or above transition levels or the lowest usable flight level, whichever is applicable, an aircraft shall be flown at flight levels. References to the vertical position of the aircraft in air-ground communications shall be expressed in terms of flight levels.
2.7.3  Where adequate QNH altimeter setting reports are available, the latest and most appropriate reports shall be used for assessing terrain clearance.
2.7.4  Where the adequacy of terrain clearance cannot be assessed with an acceptable degree of accuracy by means of the QNH reports available or forecast lowest mean sea level pressure, other information shall be obtained for checking the adequacy of terrain clearance.
2.8   Approach and landing
2.8.1  Before beginning the initial approach to an aerodrome, the number of the transition level shall be obtained.

Note: The transition level is normally obtained from the appropriate air traffic services unit.

2.8.2  Before descending below the transition level, the latest QNH altimeter setting for the aerodrome shall be obtained.

Note: The latest QNH altimeter setting for the aerodrome is normally obtained from the appropriate air traffic services unit.

2.8.3  As the aircraft descends through the transition level, the reference for the vertical position of the aircraft shall be changed from flight levels (1013.2 hPa) to altitudes (QNH). From this point on, the vertical position of the aircraft shall be expressed in terms of altitudes.
2.9   Missed approach
2.9.1  The relevant parts of “Take-off and climb”, “En route”, and “Approach and landing” shall apply in the event of a missed approach.

3.   Description of altimeter setting region(s)

3.1   Regional pressure setting
3.1.1  Aircraft flying at or below the transition altitude in Class G airspace within the Tirana FIR shall use the current reported QNH of Tirana Airport as the regional pressure setting.
3.1.2  Regional QNH are provided in MET broadcasts and are available on request from the appropriate ATS units.
3.1.3  QNH values provided to aircraft shall be rounded down to the nearest lower whole hectopascal.

4.   Procedures for operators and pilots

4.1   Flight planning
4.1.1  The levels at which a flight is to be conducted shall be specified in a flight plan:
  1. in terms of flight levels if the flight is to be conducted at or above the transition level, and
  2. in terms of altitude if the flight is to be conducted at or below the transition altitude.
4.1.2  The altitudes or flight levels selected for a flight shall ensure terrain clearance at all the points along the route to be flown and shall meet ATC requirements.
4.1.3  The levels at which a flight is to be conducted shall be specified in a flight plan:
  1. as flight levels if the flight is to be conducted at or above the transition level (or the lowest usable flight level, if applicable); and
  2. as altitudes if the flight is to be conducted at or below the transition altitude.
4.1.4  The altitudes or flight levels selected for flight:
  1. should ensure adequate terrain clearance at all points along the route;
  2. should satisfy air traffic control requirements; and
  3. should be compatible with the table of cruising levels in ENR 1.7.5, if relevant.
4.2   Terrain clearance
4.2.1  The determination of lowest usable flight levels by air traffic control units within controlled airspace does not relieve the pilot-in-command of the responsibility for ensuring that adequate terrain clearance exists, except when an IFR flight is being vectored by radar.

Note: Minimum vectoring altitudes are published on the ATC Surveillance Minimum Altitude Chart.

4.2.2  If an aircraft is cleared by ATC to an altitude which the pilot-in-command finds unacceptable due to low temperature, then the pilot-in-command should request a higher altitude. If such a request is not received, ATC will consider that the clearance has been accepted and will be complied with.
4.2.3  The pilot is responsible for altimeter corrections for pressure, temperature and, where appropriate, wind and terrain effects, except when under radar vectoring. In that case, the radar controller issues clearances such that the prescribed obstacle clearance will exist at all times, taking the cold temperature correction into account.
4.3   Provision of altimeter setting information
4.3.1  Appropriate ATS units shall at all times have available for transmission to aircraft in flight, on request, the information required to determine the lowest flight level which will ensure adequate terrain clearance on routes or segments of routes for which this information is required.
4.3.2  ACC shall have available for transmission to aircraft, on request, an appropriate number of QNH reports or forecast pressures for the adjacent FIRs.
4.3.3  The flight crew shall be provided with the aerodrome QNH, temperature and transition level in due time prior to reaching it during descent. This may be accomplished by voice communications or ATIS broadcast.
4.3.4  The transition level shall be included in approach clearances or requested by the pilot.
4.3.5  A QNH altimeter setting shall be included in the descent clearance when first cleared to an altitude below the transition level, in approach clearances or clearances to enter the traffic circuit, and in taxi clearances for departing aircraft, except when it is known that the aircraft has already received the information.
4.3.6  QNH values are given in hectopascals (hPa). QNH in milimetres (Hg) are available on request.
4.3.7  Altimeter settings provided to aircraft shall be rounded down to the nearest lower whole hectopascal.

5.   Table of cruising levels

TRACK
From 000 degrees to 179 degrees From 180 degrees to 359 degrees
IFR FlightsVFR FlightsIFR FlightsVFR Flights
LevelLevelLevelLevel
FLFeetMetresFLFeetMetresFLFeetMetresFLFeetMetres
101000300---202000600---
303000900353500105040400012004545001350
5050001500555500170060600018506565002000
7070002150757500230080800024508585002600
90900027509595002900100100003050105105003200
110110003350115115003500120120003650125125003800
130130003950135135004100140140004250145145004400
150150004550155155004700160160004900165165005050
170170005200175175005350180180005500185185005650
190190005800195195005950200200006100205205006250
210210006400215215006550220220006700225225006850
230230007000235235007150240240007300245245007450
250250007600255255007750260260007900265265008100
270270008250275275008400280280008550285285008700
290290008850300300009150
310310009450320320009750
33033000100503403400010350
35035000106503603600010950
37037000113003803800011600
39039000119004004000012200
41041000125004304300013100
45045000137004704700014350
49049000149505105100015550
etc.etc.etc.etc.etc.etc.

Note 1: For VFR flights above 3000 FT above ground or water.

Note 2: For flights above the TA, the lowest FL to be selected is the first appropriate flight level corresponding with, or immediately above, the common TL for the Tirana FIR.