TEORIJA KONTROLE ZRAČNOG PROMETA I - e-Studente-student.fpz.hr/Predmeti/T/Teorija_kontrole...Teorija k ontrole zračnog prometa I– Nastavna cjelina 7 43 Transition Altitude •

Teorija kontrole zračnog prometa I –

nastavna cjelina 71

Level in aviation

Altimeter setting procedures

Biljana Juričić, DSc

Fakultet prometnih znanosti

Zavod za aeronautiku

Katedra za kontrolu leta

TEORIJA KONTROLE ZRAČNOG

PROMETA I

Teorija kontrole zračnog prometa I–

Nastavna cjelina 72

5.ODREĐIVANJE I DODJELA VISINE (ALTIMETRY AND LEVEL ALLOCATION)

• 5.1.Određivanje visine(Altimetry)Razumjeti odnos između visine, visine leta i razine leta; QFE, QNH, standardni pritisak.(Appreciate the relationship between height, altitude and flight level; QFE, QNH, standard pressure)

• I5.2.Prijelazna razina(Transition Level)Razumjeti odnos između prijelazne razine, prijelazne visine leta i prijelaznog sloja; ICAO Doc 4444, ICAO Doc 8168.(Appreciate the relationship between transition level, transition altitude and transition layer; ICAO Doc 4444, ICAO Doc 8168). Izračun prijelazne razine leta (Calculate transition levels)

• I5.3.Dodjela razine(Level Allocation)Opisati sustav dodjele razine krstarenja; Annex 2, tablice putnih razina.(Describe the cruising level allocation system; ICAO Annex 2, tables of cruising levels). Odabir prikladne visine; razine leta, visine u odnosu na srednju razinu mora, visine u odnosu na referentnu točku.(Choose appropriate levels; Flight levels, altitudes, heights)3Teorija kontrole zračnog prometa I

Ciljevi osposobljavanja –

- Learning Objectives:


Nastavna cjelina 73

Level in aviation

Level in aviation – generic term meaning variously:

• Altitude

• Flight Level

• Height


Nastavna cjelina 74

Altitude

• The vertical distance of a level, at which point or

an object considered as a point, is measured

from mean sea level (MSL) taking into

consideration QNH pressure.


Nastavna cjelina 75

Height

• The vertical distance of a level, at which a point

or an object is considered as a point, measured

from a specified datum taking into consideration

QFE pressure


Nastavna cjelina 76

Flight level

• A surface of constant atmospheric pressure

which is related to a specific pressure datum of

1 013.2 hPa (standard pressure - QNE) and is

separated from other such surfaces by specific

pressure intervals (18 hPa=500 ft).


Nastavna cjelina 77

Elevation

• The vertical distance of a point or an object at

surface measured from mean sea level (MSL)

taking into consideration QNH pressure.


Nastavna cjelina 78

QNH

• altimeter subscale setting of pressure value at the

aerodrome elevation which is calculated using pressure

reduction to MSL

• The altimeter sub-scale setting to obtain elevation when

on the ground.


Nastavna cjelina 79

QNE

• altimeter subscale setting of pressure value of ISA

standard atmosphere 1013,25 hPa


Nastavna cjelina 710

QFE

• altimeter subscale setting of pressure value

measured at the aerodrome elevation



USS

QNE

QFE

Height

Altitude

Flightlevel (FL)

QNE<QNH

QNE>QNH

QNE=QNH

QNE

Elevation



Characteristic of atmosphere

hp

1∝ 1 hPa ≈ 30 ft



Atmospheric rule...

• The higher the level, the lower the pressure

• The lower the level, the higher the pressure



Altimeter

• equipment that measures pressure difference

between pressure reference datum and actually

mesured pressure value and calculates

corresponding vertical distance

• reference data: QNH, QNE, QFE



• setting the right pressure datum is essential for calculating the real vertical position of the aircraft

• if not, altimeter indicates correct value but real altitude of the aircraft is different (aircraft is higher or lower then it should be)

• the pressure datum in such cases is higher or lower in accordance with MSL



Example 1.

• QNH is 1000 hPa

• aircraft 1 is at altitude 7500 ft

• aircraft 2 is entering the same airspace at altitude

8500 ft but with incorrect pressure of 1036 hPa

What is the real vertical distance between aircraft??



8500 ft

7500 ft

USS

QNH=1000 hPa

MSL

QNH=1036 hPa

36*30=1080 ft

1080 ft !!1

2

Incorrect reference datum!

Altitude7420 ft



Example 2

• upper limit of the defined airspace is 9000 ft MSL

• QNH is 1036 hPa

• aircraft 1 is at altitude 7500 ft

• aircraft 2 is entering the same airspace at altitude

8500 ft but with incorrect pressure of 1000 hPa



7500 ft

8500 ft

9000 ft

9580 ft

USS

QNH=1036 hPa

MSL

QNH=1000 hPa

36*30=1080 ft

8500 ft !!

1

2


Altitude

36*30=1080 ft



• same problems can appear with obstacle

clearance

• if IFR aircraft is on the flight level which coinside

with minimum obstacle clearance altitude and

QNH is less then QNE, then minimum obstacle

clearance is less then it should be CFIT – Controlled Flight Into

Terrain



FL

USS

MSLIncorrect reference datum!

Altitude

if QNH<<<<QNE

MOCA

y<<<<x

IFR flight

x

FL 0



if QNH<<<<QNE VFR flight

USS

MSL∆∆∆∆pIncorrect reference datumof QNE!

Altitude

MOCA

xy



• two aircraft are on head-on directions but with differently set pressure (aircraft 2 has wrong setting)

• What is the real vertical distance between

aircraft??

Example 3



USS

QNH=990 hPa

MSL20*30=600 ft

1

2


Altitude

QNH=1010 hPa1000 ft

Real vertical distance between aircraft is 400 ft!

600 ft

400 ft



Example 4

• aircraft 1 is on the runway with altimeter set to

the QNH and shows 510 ft

• aircraft 2 is in the vicinity of aerodrome with

altimeter set to the QFE=990hPa an shows 650 ft

• altitude of aircraft 2?

• QNH?



USS

MSL

650 ft, QFE=990 hPa

510 ft, QNH

510 ft, QNH

Altitude

Height

QNH=1007 hPa!



• aircraft 1 is at height 3500 ft with altimeter set to QFE = 980 hPa

• elevation of aerodrome is 150 m

• What is the altitude of aircraft 1 and QNH?

• aircraft 2 enters same airspace with altitude of 4500 ft, but with wrongly set QNH of 1010 hPa

• What is the real vertical separation between aircraft?

Example 5



3500

4500

USS

MSL

3500 ft, QFE=980 hPa

510 ft, QNH=?

150 m

Altitude

Height

ft

4500 ft, QNH=1010 hPa

x=?



RWY

TA

TL

TLY

QNH

QNE

QNE

QNE

QNE

QNH

QNH

QNH

MSL

Altimeter setting procedures



Altimeter setting

When approaching and departing from aerodrome pilot shall set altimeter according to following levels:

Transition Altitude (TA)

Transition Level (TL)

Transition Layer (TLY)



Transition Altitude (TA)

• highest possible altitude at which aircraft can

operate with alimeter set to QNH

• designated by the State and published in AIP

• it can be different for every aerodrome or unique

for whole airspace



Transition Level (TL)

• lowest possible flight level at which aircraft

can operate with alitimeter set to QNE

• depends on QNH

• ATC gives information about TL when aircraft

is in approach



Transition Layer (TLY)

• area between transition level and transition

altitude

• depends on QNH



Calculation of transition levels

• 3 different cases:

QNH < QNE

QNH = QNE

QNH > QNE



if QNH < QNE

QNE

QNH

QNH<QNE ⇒ ∆∆∆∆ P

∆ h = ∆ P*30 ft

0

FL

alt.

∆ h = ∆ P*30 ft



if QNH = QNE

QNE

QNH

QNH=QNE ⇒ ∆∆∆∆ P=0

0

TL

TA



if QNH > QNE

QNH

QNE

QNH>QNE ⇒ ∆∆∆∆ P

∆ h = ∆ P*28 ft

0

alt.

TA

∆ h = ∆ P*28 ft



Example 1 TA=4000 ftQNH<QNE ⇒ ∆ PQNH=1000 hPa∆ P= 13 hPa ⇒13*30=390 ft

QNH

∆∆∆∆ h =390 ft

0 QNE

10

20

30

40

50

1000

2000

3000

4000

5000

∆∆∆∆ h =390 ft

TL=FL45

TLY=110 FT45



Example 2 TA=4000 ftQNH=QNE ⇒ ∆ PQNH=1013 hPa∆ P= 0 hPa

QNH

∆∆∆∆ h = 0 ft

0

QNE

10

20

30

40

50

1000

2000

3000

4000

5000

∆∆∆∆ h =0 ft

TL=FL40

TLY= 0 FT



USS

MSL∆∆∆∆p=QNH1-QNH2Indicated altitude 1- but Incorrect reference datum of QNH1!

Altitude1

xy

QNH1

QNH1

QNH2

Actual altitude AMSL(altitude1- ∆∆∆∆p*30)



• if aircraft set altimeter at departure aerodrome at QNH1 and is flying en-route at altitude 7000 ft with the same pressure towords the high terrain, aircraft will be at lower level above terrain with possible obstacle clearance infringed



• to avoid such errors it is necessary to update QNH (QNH2 at previous picture) using values supplied by an aerodrome with ATC nearest to the route of flight



Transition Altitude

• A transition altitude shall normally be specified

for each aerodrome by the State in which the

aerodrome is located

• Where two or more closely spaced aerodromes

are located so that coordinated procedures are

required, a common transition altitude shall be

established. This common transition altitude shall

be the highest that would be required if the

aerodromes were considered separately



• As far as possible, a common transition altitude should be established for

– groups of aerodromes of a State or all aerodromes of that State

– aerodromes of adjacent States (on the basis of an agreement)

– States of the same flight information region (on the basis of an agreement)

– States of two or more adjacent flight information regions or one ICAO region (on the basis of an agreement)

– for aerodromes of two or more ICAO regions when agreement can be obtained between these regions

Transition Altitude



Transition Altitude

• The height above the aerodrome of the transition

altitude shall be as low as possible but normally

not less than 900 m (3 000 ft)

• Transition altitude may be established for a

specified area on the basis of regional air

navigation agreements

• Transition altitudes shall be published in

aeronautical information publications and shown

on the appropriate charts



Transition

• in TMA, in approach procedures aircraft fly at flight levels

with altimeter set to QNE till reaching transition level.

Then pilot change altimeter setting to QNH and vertical

position of aircraft is exspressed as altitude

• when departing, aircraft receive QNH information and

set altimeter to QNH. Its level is express as altitude untill

aircraft reach transition altitude when pilot set altimeter

to QNE and vertical position of aircraft is expressed as

flight level



• ATC may clear aircraft (turbo-prop) to operate

using QNH above transition level if so required

for the purpose of the uninterrupted descent

• ATC gives altitude to descent to and QNH

Transition-exception



• if TA is defined for every aerodrome then aircraft

outside TMA fly according to semicircular system

of cruising levels

• ICAO Annex 6, Doc 8168:

– when no transition altitude is established for the

area, aircraft in the en-route phase shall fly at

flight levels



Terrain clearance

• QNH altimeter setting reports should be provided from sufficient

locations to permit determination of terrain clearance with an

acceptable degree of accuracy

• For areas where adequate QNH altimeter setting reports cannot be

provided, the appropriate authorities shall provide the information

required to determine the lowest flight level which will ensure

adequate terrain clearance. This information shall be made

available in the most usable form.

• Appropriate services shall at all times have available the

information required to determine the lowest Flight level which will

ensure adequate terrain clearance for specific routes or segments

of routes. This information shall be made available for flight

planning purposes and for transmission to aircraft in flight, on

request.



• ATC is responsible for terrain clearance of aircraft only if

aircraft is under radar vectoring procedures and ATC

takes into consideration MRVA

• MRVA – Minimum Radar Vectoring Altitude

• MRVA - the lowest altitude which may be used for radar

vectors for IFR flights taking into account the minimum safe

height (of 1000 ft above the highest obstacle within a radius

of 8 km) and airspace structure (lower limit of the controlled

airspace plus a buffer of 500 ft). The MRVA is rounded to the

nearest 100-ft interval.



Transition layer

• in some States, the minimum depth of transition

layer may be established



• aircraft shall fly corresponding to the magnetic track in the table of cruising levels in Annex 2

• Flight level zero shall be located at the atmospheric pressure level of 1 013.2 hPa. Consecutive flight levels shall be separated by a pressure interval corresponding to at least 500 ft (152.4 m) in the standard atmosphere.

Semi-circular table of cruising levels



ODD

000

179°180°

359°

EVEN




• VFR flight level is IFR flight level + 500 ft

(IFR FL 70, VFR FL 75)

• if TA is established for whole FIR then VFR flights

above TA will fly using flight levels and at or

below will fly at altitudes (in Croatia)...

• pilot of VFR flight selects flight level


for VFR flights



• ATC allocates flight level or altitude for IFR flights

in controlled airspace


for IFR flights



Non-RVSM Airspace



RVSM airspace



ODD EVENIFR VFR IFR VFR1000 20003000 3500 4000 45005000 5500 6000 65007000 7500 8000 85009000 9500 TA 100 105110 115 120 125... ... ... ...270 275 280 285290 - 310 -


for FIR Zagreb



Calculations of TL, TLY

1. QNH=990 hPA, TA=5000 ft. Calculate TL, TLY.

2. QNH=1043 hPa, TA=8000 ft. Calculate TL, TLY.

3. QNH=980 hPa, TA=7500 ft, TLY=min 500 ft. Calculate TL.






Example 1– flight level

USS

MSL

QNH=1020 hPa QNH=1025 hPa QNH=1020 hPa QNH=1030 hPa

TA=6000 ft

QNE=1013 hPa

∆∆∆∆p=QNH-1013



USS

MSL

QNH=1010 hPa QNH=1015 hPa QNH=1020 hPa QNH=1030 hPa

TA=6000 ft

Example 2– flight level

∆∆∆∆p=1013-QNH

QNE=1013 hPa



Calculations of TL, TLY1. QNH=995 hPA, TA=5000 ft. Calculate TL, TLY.

2. QNH=1040 hPa, TA=6500 ft. Calculate TL, TLY.



5. QNH=1036 hPa, TA=4500 ft, TLY=min 1000 ft. Calculate TL.6. TA=5000 ft, QNH=970 hPa. A/c is at FL050. Where is FL 0? What is the altitude of the a/c?

7. TA=6500 ft, A/c is constantly at FL080. In QNH=1040 hPa. Where is FL 0? What is the altitude of the a/c?

8. In Area 1 QNH =991 QNH, in Area 2 QNH=999 hPa and in Area 3=1022 hPa. Draw path of the a/c. A/c is at FL100.

9. A/c is approaching aerodrome with height=650 ft. QNH=1015 hPa. Another a/c is at the same level but with altimeter set to QNH. Its altimeter shows 3500 ft. Calculate QFE and aerodrome’s elevation in meters.

10. Third aircraft is entering the same airspace with FL050. What is the vertical separation between these aircraft?

11. Aircraft is at 6000 ft, QNH=980 hPa and its MSH is 2000 ft above the highest obstacle in the radius of 8 km. Another aircratf is entering the same airspace with the wrong altimeter setting QNH=1028. What is the vertical terrain separation of the second aircraft?

12. Elevation of the terrain is 2000 m. What must be the lowest altitude or FL at which aircraft will have MSH=2000 ft. TA=9000 ft.



1. TA=4000 ft, QNH=970 hPa. A/c is at FL040. Where is FL 0?

What is the altitude of the a/c?

2. TA=4500 ft, A/c is constantly at FL070. In QNH=1035

hPa. Where is FL 0? What is the altitude of the a/c?

3. In Area 1 QNH =980 QNH, in Area 2 QNH=1000 hPa

and in Area 3=1030 hPa. Draw a path of the a/c.

A/c is at FL120. Draw FL0.

Procedures Applicable to

Operators and Pilots



Flight Planning

• the 3 requirements altitudes or flight levels

selected by the Operator should:

– ensure adequate terrain clearance at all points

along the route to be flown

– satisfy ATC requirements

– be compatible with the cruising levels appropriate

to the magnetic tracks



Pre-flight Operational Test

• QNH – AD elevation + the height of the altimeter within the tolerance ± 60 ft for altimeters with the test range of 0 to 30000 ft and ± 80 ft for altimeters with the test range of 0 to 50000 ft

• QFE - the height of the altimeter within the tolerance ± 60 ft for altimeters with the test range of 0 to 30000 ft and ± 80 ft for altimeters with the test range of 0 to 50000 ft



Thank you!! ☺

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TEORIJA KONTROLE ZRAČNOG PROMETA I - e-Studente-student.fpz.hr/Predmeti/T/Teorija_kontrole...Teorija k ontrole zračnog prometa I– Nastavna cjelina 7 43 Transition Altitude •