ENR 1.7  Altimeter Setting Procedures

1.7.1   Introduction

The altimeter setting procedures in use conform to those contained in ICAO PANS-OPS Doc. 8168 - Volume III and are given in full below.

Transition altitudes are given in Sub-section 1.7.2 below and AD-2.17 for each aerodrome. In addition, transition altitudes are given on instrument approach charts.

QNH reports and temperature information for use in determining adequate terrain clearance is provided in MET broadcasts and is available on request from air traffic service units. QNH values are given in whole hectopascals.

1.7.2   Basic altimeter setting procedures

1. General

1.1 A transition altitude is specified for each aerodrome.

1.2 Vertical positioning of aircraft when at or below the transition altitude is expressed in terms of altitudes where as such positioning at or above the transition level is expressed in terms of flight levels. While passing through the transition layer, vertical positioning is expressed in terms of altitude when descending, and in terms of flight level when ascending.

1.3 Flight level zero is located at the atmospheric pressure level of 1013.2 HPA (29.92 inHg). Consecutive flight levels are separated by a pressure interval corresponding to 500 feet (152.4 metres) in the Standard Atmosphere.

1.4 Lisboa FIR - Table of transition altitudes and levels

LocationTransition Altitude (FT)QNH
<942.2942.2
to
959.4
959.5
to
977.1
977.2
to
995.0
995.1
to
1013.2
1013.3
to
1031.6
1031.7
to
1050.3
>1050.3
Transition Level
Cascais AD
Faro AD
Lisboa AD
Porto AD
Beja AD
Évora AD
40007570656055504540
Madeira AD
Porto Santo AD
50008580757065605550
Vila Real AD
Bragança AD
800011511010510095908580

1.5 Santa Maria FIR - Table of transition altitudes and levels

LocationTransition Altitude (FT)QNH
<942.2942.2
to
959.4
959.5
to
977.1
977.2
to
995.0
995.1
to
1013.2
1013.3
to
1031.6
1031.7
to
1050.3
>1050.3
Transition Level
Santa Maria AD40007570656055 504540
Flores AD
Horta AD
Lajes AD
Pico AD
Graciosa AD
S. Jorge AD
Corvo AD
50008580757065605550
Ponta Delgada AD60009590858075 706560

2. Take-off and climb

QNH altimeter setting is made available to aircraft prior to take-off.

QFE altimeter setting shall be passed to aircraft on request.

Vertical positioning of aircraft during climb is expressed in terms of altitudes until reaching the transition altitude above which vertical positioning is expressed in terms of flight levels.

3. Vertical separation en-route

Vertical separation during en-route flight shall be expressed in terms of flight levels at all times.

4. Approach and landing

A QNH altimeter setting is made available in approach clearances and in clearances to enter the traffic circuit.

A QFE altimeter setting shall be passed to aircraft on request.

The transition level is made available in approach clearances.

Vertical positioning of aircraft during approach is controlled by reference to flight levels until reaching the transition level below which vertical positioning is controlled by reference altitudes.

5. Missed approach

The relevant portions of paragraphs 1.2, 2 and 4 and shall be applied to the case of a missed approach.

1.7.3   Altimeter setting region(s)

NIL

1.7.4   Procedures applicable to operators (including pilots)

Flight planning

The levels at which a flight is to be conducted shall be specified in a Flight Plan:

  1. in terms of flight level if the flight is to be conducted at or above the transition level, and
  2. in terms of altitudes if the flight is to be conducted in the vicinity of an aerodrome and at or below the transition altitude.

1.7.5   Table of cruising levels

NOTE: Examples of the relationship between flight levels and altimeter indications are given in the following table, the metric equivalents being approximate:

MAGNETIC TRACK
From 090 degrees to 269 degrees (ODD’s)From 270 degrees TO 089 degrees (EVEN’s)
IFR FlightsVFR FlightsIFR FlightsVFR Flights
FLALTITUDEFLALTITUDEFLALTITUDEFLALTITUDE
MetresFeetMetresFeetMetresFeetMetresFeet

10

300

1000

-

-

-

20

600

2000

-

-

-

30

900

3000

35

1050

3500

40

1200

4000

45

1350

4500

50

1500

5000

55

1700

5500

60

1850

6000

65

2000

6500

70

2150

7000

75

2300

7500

80

2450

8000

85

2600

8500

90

2750

9000

95

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

210

6400

21000

220

6700

22000

230

7000

23000

240

7300

24000

250

7600

25000

260

7900

26000

270

8250

27000

280

8550

28000

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

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