← The Saudi aviation reference, in one place.

Saudi AIP19 sections

Saudi eAIP ENR 1.7 — Altimeter Setting Procedures

Reproduced for study. Always verify against the official GACAR at gaca.gov.sa.

Saudi eAIP, AIRAC AMDT 05/26 — effective 14 MAY 2026. Verify against the current AIP at aimss.sans.com.sa before any operational use.

ENR 1.7 ALTIMETER SETTING PROCEDURES

1.7.1 Introduction

1.7.1.1. The altimeter setting procedures in use generally conform to those contained in ICAO Doc 8168, Vol. Ill, Section 2 and ICAO Doc 4444-PANS ATM are given in full below. Differences are shown in quotation marks.

1.7.1.2. Transition altitudes are given on AD 2.17, instrument approach charts and ATC surveillance Minimum Altitude charts.

1.7.1.3. QNH and temperature data, for use in determining adequate terrain clearance, are included in ATIS broadcasts, where provided, or are available on request from the appropriate ATS unit. QNH values are given in hectopascals (hPa), rounded down to the nearest whole unit.

1.7.2 Basic altimeter setting procedures

1.7.2.1 General

1.7.2.1.1. A common TA of 13 000 FT and a fixed transition level (TL) of FL 150 are established for the whole of Jeddah FIR airspace.

Note 1

: The altitude equivalent of FL 150, calculated from the lowest known MSL pressure in Saudi Arabia (986 hPa), is 14 265 FT and, therefore, a minimum of 1 000 FT of vertical separation exists in the transition layer under all surface atmospheric pressure conditions; thus, simultaneous flight at both TA and TL is always permissible, but level flight within the layer is prohibited.

Note 2

: The classification of the airspace within the transition layer assumes the classification of the airspace within which it resides.

1.7.2.1.2. The vertical position of aircraft is expressed in terms of:

altitude, when at or below the TA and when descending through the transition layer; and

flight level, when at or above the TL and when climbing through the transition layer.

1.7.2.1.3. Flight level zero is located at the atmospheric pressure level of 1 013.2 hPa. Consecutive flight levels are separated by a pressure interval corresponding to 500 FT (152.4 M) in the ICAO International Standard Atmosphere ( ISA ).

1.7.2.1.4. No altimeter correction for pressure and temperature have been applied for minimum levels

1.7.2.2 Take-off and climb

1.7.2.2.1. A QNH altimeter setting is available for take-off either:

Through ATIS broadcast or if available, ATIS data link, or RTF at aerodromes with AFIS, TWR, and APP services; or

from Jeddah ACC for uncontrolled aerodromes.

1.7.2.2.2. Vertical position of aircraft during climb is controlled by reference to altitude until reaching the TA, and by reference to flight level above the TA.

1.7.2.3 Vertical separation enroute

1.7.2.3.1. Vertical separation of aircraft enroute is controlled by reference to:

altitude, when at and below the TA; and

flight level, when at and above the TL.

1.7.2.3.2. Vertical separation is applied by requiring aircraft to fly at the appropriate hemispherical level prescribed in ICAO Annex 2, Appendix 3, according to the magnetic track of the aircraft, except that non hemispherical levels are also assigned on one way airways if necessary to improve traffic flow or avoid double level changes, as shown below:

IFR ALTITUDES 13 000 FT AND BELOW

359°

000°

EVEN

ODD

2 000

4 000

6 000

1 000

8 000

3 000

10 000

5 000

12 000

7 000

9 000

11 000

13 000

180°

179°

IFR FLIGHT LEVELS FL 150 UP TO FL 290

359°

000°

EVEN

ODD

160

180

200

150

220

170

240

190

260

210

280

230

250

270

180°

179°

VFR ALTITUDES BELOW 13 000 FT

359°

000°

EVEN

ODD

2 500

4 500

6 500

1 500

8 500

3 500

10 500

5 500

12 500

7 500

9 500

11 500

180°

179°

IFR FLIGHT LEVELS (FL290 - FL410) INCLUSIVE IN RVSM AIRSPACE "APPLY 2000 INTERVALS"

359°

000°

EVEN

300

ODD

320

290

340

310

360

330

380

350

400

370

430

390

470

410

510

450

550

490

590

530

570

180°

179°

Note 1

: Aircraft operating on ATS routes above FL 600 or below ALT 11 500 FT will be outside controlled airspace and, therefore, will be provided with flight information service only.

Note 2

: Since VFR is not permitted above FL 150, the highest usable VFR level is ALT 12 500 FT.

Note 3

: Some of the lower levels shown above may not be usable due to terrain clearance requirements.

1.7.2.3.3. Current QNH reports are used to determine the terrain clearance for flights operating at or below the TA. The chart on page ENR 6.11 Altimeter Setting Observing Stations - Index Chart depicts the network of observing stations, which report QNH hourly; these reports are provided direct to ATS units established at aerodromes and, in the form of an hourly METAR bulletin, to Jeddah ACC, Dammam Approach, Abha Approach , Riyadh Approach, Tabuk Approach, Jazan approach, Taif approach, Sultan approach, Gassim approach and Hail approach.

1.7.2.4 Approach and landing

1.7.2.4.1 A QNH altimeter setting is available either:

in routine approach and landing information, by ATIS (where applicable) or RTF, at aerodromes with ATS units; or

from Jeddah ACC, Dammam Approach, Abha Approach, Riyadh Approach, Tabuk Approach, Jazan approach, Taif approach, Sultan approach, Gassim approach or Hail approach as appropriate, for aerodrome without ATS units. When altimeter sitting on which approach based not available, approach not authorized.

1.7.2.4.2. A QFE altimeter setting is available on request at aerodromes with ATS units; QFE is NOT readily available at other aerodromes. Where available, the QFE reference datum is either:

runway threshold elevation - for all precision runways and those non-precision runways with a threshold elevation 7 FT or more below aerodrome elevation; or

aerodrome elevation - for all other runways.

1.7.2.4.3. Vertical positioning of aircraft during approach is controlled by reference to flight levels until reaching the TL, and by reference to altitude below the TL. However, this does not preclude pilots from using either:

QNH setting from top of descent, provided that level flight above the TA is neither indicated nor anticipated; or

QFE setting, where available, for terrain clearance purposes during final approach to the runway.

1.7.2.5 Missed approach

The relevant portions of the preceding paragraphs apply in all cases of missed approach.

1.7.3 Description of altimeter setting region

The altimeter setting regions are shown on the Altimeter Setting Observing Stations Index Chart ENR 6.11.

1.7.4 Procedures applicable to operators (including pilots)

1.7.4.1 Flight planning

1.7.4.1.1. The levels at which a flight is to be conducted shall be specified in a flight plan in terms of:

flight level, when the flight is to be operated at or above the TL; and

altitude, when the flight is to be operated at or below the TA.

1.7.4.1.2. The levels selected should:

ensure adequate terrain clearance for the entire route; and

satisfy ATC requirements; and

be compatible with those shown in paragraph 2.3.2.

Note 1

: The information required to determine the lowest level which will ensure adequate terrain clearance may be obtained from the appropriate services unit, e.g. ATS, AIS or MET.

Note 2

: The levels selected will depend upon the accuracy with which the vertical position of such levels relative to the terrain can be estimated which, in turn, is dependent upon the type of meteorological information available. A lower level may be used with confidence when its position is based on current information relevant to the particular route to be flown and when it is known that amendments to this information will be available in flight; but a higher level will be needed when based on information less relevant to the particular route to be flown and the time at which the flight is to be conducted. See chart on page ENR 6.11.

Note 3

: Flights over level terrain may often be conducted at one level, whereas flights over mountainous terrain may require several changes in levels to account for changes in the elevation of the terrain. The use of several levels may also be needed in order to comply with ATS requirements.

1.7.4.2 Pre-flight operational test

1.7.4.2.1. The following test should be performed by flight crew members prior to take-off; the purpose of this test being to establish whether or not the altimeter readout is within the permissible range for that instrument.

1.7.4.2.2. With the aircraft at a known elevation on the aerodrome, set the altimeter pressure scale to the appropriate current value (QNH or QFE). Vibrate the instrument by tapping unless a mechanical vibration is provided. A serviceable altimeter will indicate either:

QNH - the elevation of the point selected plus the height of the altimeter above this point; or

QFE - the height of the altimeter in relation to the QFE reference datum;

within a tolerance of plus/minus 60 FT or 80 FT for altimeters with test ranges up to 30 000 FT or 50 000 FT respectively.

Note 1

: When the altimeter does not indicate the reference elevation or height exactly, but is within the specified tolerance, no adjustment of this indication should be made either by means of the pressure adjustment knob or other adjustment on the altimeter at any stage of a flight. Furthermore, any error that is within tolerance, noted during pre-flight check on the ground, should be ignored by the pilot during flight.

Note 2

: The tolerances specified above are considered acceptable for aerodrome elevations up to 3 500 FT ISA. The tables below indicate the permissible range for different aerodrome elevations and when pressure is lower than ISA.

Table 1

Tolerances for altimeters

with test range up to

30 000 FT.

ELEV

(FT)

Permissible

Range

(FT)

2 000

1 940 to 2 060

3 000

2 930 to 3 070

4 000

3 925 to 4 075

5 000

4 920 to 5 080

6 000

5 915 to 6 085

7 000

6 905 to 7 095

Table 2

Tolerances for altimeters

with test range up to

50 000 FT.

ELEV

(FT)

Permissible

Range

(FT)

2 000

1 900 to 2 100

3 000

2 895 to 3 105

4 000

3 885 to 4 115

5 000

4 875 to 5 125

6 000

5 865 to 6 135

7 000

6 855 to 7 145

1.7.4.3 Take off and climb

1.7.4.3.1. Prior to take-off, one altimeter shall be set to the latest QNH available for the aerodrome.

1.7.4.3.2. During climb, all references to the vertical position of the aircraft in air-ground communications shall be expressed in terms of:

altitude, up to and while at the TA ; and

flight level, above the TA.

1.7.4.3.3. The reference to vertical position of the aircraft shall be changed from altitude (QNH ) to flight level (ISA 1 013.2 hPa ) when leaving or passing the TA.

1.7.4.4 Enroute

1.7.4.4.1. Vertical separation during enroute flight is accomplished as follows:

at or below the TA, aircraft shall be flown at altitudes and references to vertical position in air-ground communications shall be expressed in such terms; and

at or above the TL , aircraft shall be flown at flight levels and references to vertical position in air-ground communications shall be expressed in such terms.

1.7.4.4.2. It is essential that all aircraft operating in the same airspace segment use the same altimeter setting reference to ensure that vertical separation is not infringed and, therefore, aircraft flown entirely in accordance with paragraph 1.7.4.4.1 a) above shall set QNH as follows:

within a TMA, the QNH provided for the area by the controlling ATS unit except that aircraft destined to other aerodromes within that same TMA shall set the appropriate aerodrome QNH when entering the relevant ATZ or, where no ATZ is established, the aerodrome traffic circuit; or

elsewhere, the QNH for the nearest on track station, the changeover from the station QNH behind the aircraft to that ahead being made at the mid point between the two stations.

Note

: This does not preclude aircraft using off-track QNH reports to assess terrain clearance in accordance with paragraph 1.7.4.4.3 below.

1.7.4.4.3. Terrain clearance shall be assessed using the latest and most appropriate QNH altimeter setting reports available.

1.7.4.4.4. Where the adequacy of terrain clearance cannot be assessed with an acceptable degree of accuracy by means of the QNH reports available, other information shall be obtained from the appropriate services unit for checking the adequacy of terrain clearance.

1.7.4.5 Approach and landing

1.7.4.5.1. Prior to descending below the TL, the latest QNH altimeter setting for the aerodrome shall be obtained.

1.7.4.5.2. On descending below the TL, the reference for vertical position shall be changed from flight level (ISA 1 013.2 hPa) to altitude (QNH) and, thereafter, the vertical position of the aircraft shall be expressed in terms of altitude.

Note

: This does not preclude a pilot using either:

QFE for terrain clearance during final approach in accordance with 1.7.4.5.3 below; or

the change of reference for vertical position from flight level to altitude above the TL, when so cleared by the appropriate ATS unit, after approach clearance has been issued and the descent to land commenced, provided that level flight above the TA is neither indicated nor anticipated.

1.7.4.5.3. When an aircraft is cleared as number one to land and is completing its approach using QFE, vertical position shall be expressed in terms of height, above the aerodrome reference datum used in establishing OCH, during that portion of its flight for which QFE may be used.

The relevant portions of the preceding paragraphs apply in all cases of missed approach.

1.7.5 Tables of cruising levels

The cruising levels to be observed when so required are as follows:

in areas where, on the basis of regional air navigation agreement and in accordance with conditions specified therein, a vertical separation minimum (VSM) of 300 M (1 000 FT) is applied between FL 290 and FL 410 inclusive:

TABLE A

TRACK

From 000 degrees to 179 degrees **

From 180 degrees to 359 degrees **

IFR Flights

VFR Flights

IFR Flights

VFR Flights

Altitude

Metres

Feet

Metres

Feet

Metres

Feet

Metres

Feet

-90

300

1000

600

2000

900

3000

1050

3500

1200

4000

1350

4500

1500

5000

1700

5500

1850

6000

2000

6500

2150

7000

2300

7500

2450

8000

2600

8500

2750

9000

2900

9500

100

3050

10000

105

3200

10500

110

3350

11000

115

3500

11500

120

3650

12000

125

3800

12500

130

3950

13000

135

4100

13500

140

4250

14000

145

4400

14500

150

4550

15000

155

4700

15500

160

4900

16000

165

5050

16500

170

5200

17000

175

5350

17500

180

5500

18000

185

5650

18500

190

5800

19000

195

5950

19500

200

6100

20000

205

6250

20500

210

6400

21000

215

6550

21500

220

6700

22000

225

6850

22500

230

7000

23000

235

7150

23500

240

7300

24000

245

7450

24500

250

7600

25000

255

7750

25500

260

7900

26000

265

8100

26500

270

8250

27000

275

8400

27500

280

8550

28000

285

8700

28500

290

8850

29000

300

9150

30000

310

9450

31000

320

9750

32000

330

10050

33000

340

10350

34000

350

10650

35000

360

10950

36000

370

11300

37000

380

11600

38000

390

11900

39000

400

12200

40000

410

12500

41000

430

13100

43000

450

13700

45000

470

14350

47000

490

14950

49000

510

15550

51000

530

16150

53000

550

16750

55000

570

17350

57000

590

18000

59000

etc.

* Except when, on the bases of regional air navigation agreements, a modified table of cruising levels based on a nominal vertical separation minimum of 300 M ( 1000 FT ) is prescribed for use, by aircraft operating above FL 410 within designated portion of the airspace.

**Except where, on the basis of regional air navigation agreements, from 090 to 269 degrees and from 270 to 089 degrees is prescribed to accommodate predominant traffic directions and appropriate transition procedures to be associated therewith are specified.

TABLE B

TRACK

From 000 degrees to 179 degrees **

From 180 degrees to 359 degrees **

IFR Flights

VFR Flights

IFR Flights

VFR Flights

Altitude

Metres

Feet

Metres

Feet

Metres

Feet

Metres

Feet

-90

300

1000

600

2000

900

3000

1050

3500

1200

4000

1350

4500

1500

5000

1700

5500

1850

6000

2000

6500

2150

7000

2300

7500

2450

8000

2600

8500

2750

9000

2900

9500

100

3050

10000

105

3200

10500

110

3350

11000

115

3500

11500

120

3650

12000

125

3800

12500

130

3950

13000

135

4100

13500

140

4250

14000

145

4400

14500

150

4550

15000

155

4700

15500

160

4900

16000

165

5050

16500

170

5200

17000

175

5350

17500

180

5500

18000

185

5650

18500

190

5800

19000

195

5950

19500

200

6100

20000

205

6250

20500

210

6400

21000

215

6550

21500

220

6700

22000

225

6850

22500

230

7000

23000

235

7150

23500

240

7300

24000

245

7450

24500

250

7600

25000

255

7750

25500

260

7900

26000

265

8100

26500

270

8250

27000

275

8400

27500

280

8550

28000

285

8700

28500

290

8850

29000

300

9150

30000

310

9450

31000

320

9750

32000

330

10050

33000

340

10350

34000

350

10650

35000

360

10950

36000

370

11300

37000

380

11600

38000

390

11900

39000

400

12200

40000

410

12500

41000

430

13100

43000

450

13700

45000

470

14350

47000

490

14950

49000

510

15550

51000

490

14950

49000

510

15550

51000

530

16150

53000

550

16750

55000

etc.

* Except when, on the bases of regional air navigation agreements, a modified table of cruising levels based on a nominal vertical separation minimum of 300 M (1 000 FT) is prescribed for use, by aircraft operating above FL410 within designated portion of the airspace.

Related documents