Ground Limitations

Eng. Bruno Moreira

Ground Limitations
Take off lengths
Take off distances
Departure sector
Obstacle limitations
Turn limitations
Conclusion
2

Eng. Bruno Moreira

Take Off Lenghts

Runway

Rigid or flexible rectangular area on concrete or asphalt

used for take off and landing

Eng. Bruno Moreira

Take Off Lenghts

Runway : dry

neither wet nor contaminated,

including runways specially prepared to retain effectively
dry braking action even when moisture is present.

Eng. Bruno Moreira

Take Off Lengths

Runway : contaminated

when more than 25% of the area in use is covered by :

Surface water, slush or loose snow, equivalent to more than 3mm

of water;

Compacted snow;

Ice, including wet ice.

Eng. Bruno Moreira

Take Off Lengths

Runway : wet

when the area in use has a shiny appearance,

being covered by surface water, slush or loose snow,
equivalent to less than 3mm of water
6

Eng. Bruno Moreira

Take Off Lengths

Runway : damp

when the surface is not dry, but when moisture on it doesnt

give a shiny appearance.

Eng. Bruno Moreira

Take Off Lengths

Stopway

Rectangular area beyond the take off runway :

centered on the same (center)line, at least as wide as the runway,

designated by the airport authorities for use in decelerating the

aircraft in case of aborted take off.
Eng. Bruno Moreira

Take Off Lengths

Clearway

Rectangular area beyond the runway, located on the same centerline, and
under control of the airport authorities ...

Eng. Bruno Moreira

Take Off Lengths

Clearway

500 ft min

Rectangular area beyond the runway, located on the same centerline, and
under control of the airport authorities, featuring :

10

Minimum width : 500 ft

Eng. Bruno Moreira

Take Off Lengths

Clearway

500 ft min

1.25 % max

Rectangular area beyond the runway, located on the same centerline, and
under control of the airport authorities, featuring :

11

Minimum width : 500 ft

Slope < 1.25 %

Eng. Bruno Moreira

Take Off Lengths

ok
not ok
(26 max)

Clearway

500 ft min

1.25 % max

Rectangular area beyond the runway, located on the same centerline, and
under control of the airport authorities, featuring :

12

Minimum width : 500 ft

Slope < 1.25 %

No prominence except threshold lights ( if < 26 above surface)

Eng. Bruno Moreira

Take Off Lengths

Clearway

runway length

clearway length
runway

In addition, clearway cant exceed half the runway length.

( for limitation computation )
13

Eng. Bruno Moreira

Take Off Lengths

Clearway

runway length

clearway length
runway

A clearway increases the TOW, ...

... but its useless over 15% of the runway length.
14

Eng. Bruno Moreira

Ground Limitations
Take off lengths
Take off distances
Departure sector
Obstacle limitations
Turn limitations
Conclusion
15

Eng. Bruno Moreira

Take Off Distances

TORA
( Take Off Run distance Available )
TORA

Airport authorities :

16

TORA is the part of the t.o. surface free of obstacles.

It consists of a surface capable of carrying the aircraft under all

normal operating conditions.

Eng. Bruno Moreira

Take Off Distances

TORA
( Take Off Run distance Available )
TORA

Airport authorities :

TORA is the part of the t.o. surface free of obstacles.

It consists of a surface capable of carrying the aircraft under all

normal operating conditions.

It is equal to the runway length available for take off .

17

Eng. Bruno Moreira

Take Off Distances

ASDA
( Accelerate Stop Distance Available )
TORA

ASDA

It is the runway length available for acceleration and

subsequent deceleration, including stopway, if any.

18

Eng. Bruno Moreira

Take Off Distances

TODA
( Take Off Distance Available )
TORA

ASDA
TODA

It is the runway length available for take off plus adjoining

clearway, if any.

19

Eng. Bruno Moreira

Take Off Distances

Lineup adjustments

20

When the access to the runway doesnt allow positioning the

aircraft at the threshold. (e.g. 900 taxiway entry)

Depends on the type of aircraft AND runway.

Used when computing t.o. performance.

Eng. Bruno Moreira

Take Off Distances

Lineup adjustments

90 Degree Runway Entry

e.g..

21

A320
A330-300
A340-300

TODA

ASDA

42 ft
74 ft
85 ft

83 ft
158 ft
169 ft

Adjustment to ASD
TOD ::
from the nose
main gear
gear to
to the
the beginning
beginning of
of the
the runway
runway

Eng. Bruno Moreira

Summary
Take off lengths
Take off distances
Departure sector
Obstacle limitations
Turn limitations
Conclusion
22

Eng. Bruno Moreira

Departure sector
Start of flight path :
At the end of TOD
( 35 ft height )

Forecast flight path

Start of
flight path
23

Eng. Bruno Moreira

Departure sector
Start of departure sector :
End of TOD, or
End of TOD computed in the worst conditions,or
End of clearway if the planned departure route crosses this point.
1/2E0
Planned departure route

Start of
Departure sector
Start of
flight path
24

Eng. Bruno Moreira

Departure sector
Sector :

1/2E0

E = 90 m + 0.125 D

12.5 % ( 7.10 )

Forecast flight path

AIRCRAFT
TYPE

Start of
Departure sector
Start of
flight path
25

WINGSPAN

Semi-width at the
start of the
departure sector
(1/2E0)

A310-200/300

43.90 m (144 ft 1 in)

82 m (269 ft)

A318/A319/A3
20/A321

34.10 m (111 ft 10 in)

78 m (253 ft)

A330-200/300

60.30 m (197 ft 10 in)

90 m (269 ft)

A340-200/300

60.30 m (197 ft 10 in)

90 m (269 ft)
Eng. Bruno Moreira

Departure sector
Maximum width :

1/2E0

12.5 % ( 7.10 )

300 m
required navaid accuracy

Forecast flight path

Lateral distance,
Startwhen
of heading changes 15 0 :
Departure sector

if the pilot is able to maintain the required navigation accuracy

(IFR or night operations), the distance is 300 m wide.
Start of
flight path

26

Eng. Bruno Moreira

Departure sector
Maximum width :

1/2E0

12.5 % ( 7.10 )

600 m
insufficient navaid accuracy

300 m
required navaid accuracy

Forecast flight path

Lateral distance,
Startwhen
of heading changes 15 0 :
Departure sector

27

if the pilot is able to maintain the required navigation accuracy

(IFR or night operations), the distance is 300 m wide.
Start of
otherwise
a 600 m margin is required.
flight path

Eng. Bruno Moreira

Ground Limitations
Take off lengths
Take off distances
Departure sector
Obstacle limitation
Turn limitations
Conclusion
28

Eng. Bruno Moreira

Obstacle limitations
GROSS flight path :

29

the flight path actually flown by the aircraft

the f.p. computed by performance software

Eng. Bruno Moreira

Obstacle limitations
GROSS flight path :

the flight path actually flown by the aircraft

the f.p. computed by performance software

NET flight path :

Gross flight path minus mandatory reductions (JAR, FAR)

It is the reference for obstacle clearance

Mandatory reductions :
2 engines
0.8 %
30

4 engines
1%
Eng. Bruno Moreira

Obstacle limitations
GROSS flight path :

the flight path actually flown by the aircraft

the f.p. computed by performance software

NET flight path :

Gross flight path minus mandatory reductions (JAR, FAR)

It is the reference for obstacle clearance

Ex: Gross f.p: 3 %

Mandatory reductions :
2 engines
0.8 %
31

4 engines
1%
Eng. Bruno Moreira

Obstacle limitations
GROSS flight path :

the flight path actually flown by the aircraft

the f.p. computed by performance software

NET flight path :

Gross flight path minus mandatory reductions (JAR, FAR)

It is the reference for obstacle clearance

Ex: Gross f.p: 3 %

Mandatory reductions :
2 engines
0.8 %
32

4 engines
1%

obstacle min. height

Net f.p: 3 - 0.8 = 2.2 %

Eng. Bruno Moreira

Ground Limitations
Take off lengths
Take off distances
Departure sector
Obstacle limitations
Turn limitations
Conclusion
33

Eng. Bruno Moreira

Turn limitations
No track changes allowed before :
achieving
Flight
path a height equal to one half the wingspan, AND
being at least 50 ft above the end of TORA.
t.o. dist.

take off flight path

climb

straight
track

End

35 ft
Segments :
34

final
Eng. Bruno Moreira

Turn limitations
Aircraft type wingspan - minimum height to Initiate a Track Change
AIRCRAFT TYPE

35

WINGSPAN

Minimum height above end of

TORA to start a track change =
Max {Half of Wingspan , 50 ft}

A300-B2/B4/600

44.84 m (147 ft 1 in)

Half of wingspan = 74 ft

A310-200/300

43.90 m (144 ft 1 in)

Half of wingspan = 73 ft

A318/A319/A320/A321

34.10 m (111 ft 10 in)

Half of wingspan = 56 ft

A330-200/300

60.30 m (197 ft 10 in)

Half of wingspan = 99 ft

A340-200/300

60.30 m (197 ft 10 in)

Half of wingspan = 99 ft

A340-500/600

63.50 m (208 ft 2 in)

Half of wingspan = 105 ft

Eng. Bruno Moreira

Turn limitations
Underpath
a 400 ft height, no bank angle should exceed 15
Flight
t.o. dist.

take off flight path

straight
track

30 0

climb

bank :
150 max

End

400 ft

35 ft
Segments :
36

final
Eng. Bruno Moreira

Turn limitations
Above
400 ft height, bank angles must be under 25
Flight
path
t.o. dist.

50 0

take off flight path

straight
track

bank :
150 max

climb

bank :
250 max

End

400 ft

35 ft
Segments :
37

final
Eng. Bruno Moreira

Turn limitations
when bank angle >150, the whole net flight path

Flight
path
must clear all obstacles by at least 50 ft.
t.o. dist.

50 0

take off flight path

straight
track

bank :
150 max

climb

bank :
250 max

End
50 ft
min
400 ft

35 ft
Segments :
38

final
Eng. Bruno Moreira

Turn limitations
Departure sector

E0

12.5 % ( 7.10 )

Start of
Departure sector
Start of
flight path

39

Eng. Bruno Moreira

Turn limitations
Departure sector

90 m

12.5 % ( 7.10 )

Start of
Departure sector
> 30 0

Start of
flight path

40

Forecast flight path,

with heading change > 150
Eng. Bruno Moreira

Turn limitations
Departure sector
600 m
required navaid accuracy
90 m

12.5 % ( 7.10 )

Start of
Departure sector
> 30 0

Start of
flight path

41

Forecast flight path,

with heading change > 150
Eng. Bruno Moreira

Turn limitations
Departure sector

900 m
insufficient navaid accuracy
600 m
required navaid accuracy

90 m

12.5 % ( 7.10 )

Start of
Departure sector
> 30 0

Start of
flight path

42

Forecast flight path,

with heading change > 150
Eng. Bruno Moreira

Ground Limitations
Take off lengths
Take off distances
Obstacle limitations
Departure sector
Turn limitations
Conclusion
43

Eng. Bruno Moreira

Ground Limitations
Take off lengths
Take off distances
Obstacle limitations
Departure sector
Turn limitations
Conclusion
44

Eng. Bruno Moreira

Conclusion
Obstacle clearance in IFR

ground

45

Eng. Bruno Moreira

Conclusion
Obstacle clearance in IFR

46

Gross flight path

- Mandatory reduction
=
Net flight path

Eng. Bruno Moreira

Conclusion
Obstacle clearance in IFR

47

Gross flight path

- Mandatory reduction
=
Net flight path

Eng. Bruno Moreira

Conclusion
Obstacle clearance in IFR

Gross flight path

- Mandatory reduction
=
Net flight path

300 m
( 600 m if track changes > 150 )
35 ft
( 50 ft if bank angle > 150 )

48

Eng. Bruno Moreira

Conclusion
Obstacle limitations can lead to :
a lower MTOW
Obstacle
clearance in IFR
a change in t.o. route if its too penalizing

Gross flight path

- Mandatory reduction
=
Net flight path

300 m
( 600 m if track changes > 150 )
35 ft
( 50 ft if bank angle > 150 )

49

Eng. Bruno Moreira

Conclusion
Gross flight path
- Mandatory reduction
=
Net flight path

Obstacle clearance in IFR

Vertical distances :
bank angle 15 0

bank angle > 15 0

35 ft

50 ft

Lateral distances :
heading changes 15 0

heading changes > 15 0

IFR or night operations day VFR IFR or night operations day VFR
300 m
50

600 m

600 m

900 m
Eng. Bruno Moreira