1. Performance
ATC Chapter 2

2. Aim
To determine take-off and landing distances using flight manual data and the factors that affect it.

3. Briefing Objectives State terms and definitions
Calculate Pressure and Density altitudes
State factors affecting take-off performance
Calculate take-off distance required
State factors affecting landing performance
Calculate landing distance required

4. 1. Terms and Definitions Take-Off Distance Required (TODR)
Distance required to take-off and reach a screen height (usually 50ft) above the runway at take-off safety speed
Take-Off Run Required (TORR)
Actual Ground Run Required
Take-Off Safety Speed (TOSS)
Speed which gives an adequate margin above the stall speed in the take-off configuration. Must not be less than 1.2Vs
Screen Height
TORR
TODR

5. 1. Terms and Definitions Clearway
Defined area on the ground or over water that is free of obstacles, over which an aircraft may make its initial climb
Take-Off Run Available (TORA)
Length of the runway available and suitable for the ground run of an aircraft taking off
Take-Off Distance Available (TODA)
Length of take-off run available plus any clear way
Screen Height
Clearway
TORA
TODA

6. 1. Terms and Definitions Stopway
Defined area on the ground at the end of a runway suitable area in which an aircraft may stop in an emergency
Accelerate Stop Distance Available (ASDA)
Distance specified as being the effective length available for use by an aircraft executing an aborted take-off, including any Stopway
Stopway
ASDA

7. 1. Terms and Definitions Landing Distance Required (LDR)
Distance required to land from a height of 50ft above the threshold to where the aircraft comes to a complete stop
Landing Run Required (LRR)
Actual Ground Roll Required
Landing Distance Available (LDA)
Length of runway suitable for the ground roll of an aircraft beginning at the threshold or displaced threshold
50’
LRR
LDR
LDA

8. 2. Pressure and Density Altitude
International Standard Atmosphere (ISA)
ISA provides a yardstick against which we can measure the effects of changing atmospheric conditions against performance figures produced by the aircraft manufacturer
Standard ISA conditions at sea level are:
QNH 1013 hPa
Lapse rate of 1 hPa per 30ft
Temperature 15⁰C
Lapse rate of 2⁰C per 1000ft
Density Kg/M3

9. 2. Pressure and Density Altitude
Pressure Altitude
Aircraft is flying at 4500ft AMSL
QNH is 996 hPa
Temperature is 30⁰C
What is the pressure altitude?
Determine pressure variation from ISA
1013 hPa – 996 hPa = 17hPa
Multiply variation by the pressure lapse rate, 30ft per 1 hPa
17 hPa x 30ft = 510ft
Apply the variation to the aircrafts altitude
Since QNH is less than ISA, pressure altitude will be higher
=5010

10. 2. Pressure and Density Altitude
Pressure Altitude
4500ft on area QNH
Altitude
Pressure height =
=5010ft
MSL
Area QNH 996hPA
( ) x 30 = 17hPa x 30 = +510ft
17hPa difference
ISA MSL
ISA 1013 hPa

11. 2. Pressure and Density Altitude
Pressure altitude is 4000ft
QNH is 1020 hPa
Temperature is 22⁰C
What is the density altitude?
Determine temperature variation from ISA at the pressure altitude
15 ⁰C - (2x4)= 7 ⁰C
Multiply variation by the lapse rate, 120ft per 1⁰C
22⁰C - 7 ⁰C = 15 ⁰C x 120ft = 3300ft
Apply the variation to the pressure altitude
Because the temperature is greater than ISA our density altitude will be greater than our actual altitude
4000ft ft = 7300ft

12. 2. Pressure and Density Altitude
Aerodrome Elevation = 2550 ft
Step 1: Find Pressure Height 1013 – 998 = +15 x 30 = 450ft Step 2: Calculate Density height ISA temperature at 3000ft pressure height = (+15 – (2 x3) +09C Ambient temperature = +24 C Temperature deviation = 15 C Correction to pressure height for ISA +15 is (+15 x 120) = +1800ft Pressure height = 3000ft Density height = 4800ft
MSL QNH 998 hPa
Pressure height =
=3000ft
+15 x 30ft/hPa = 450ft
Std. pressure 1013hPa

13. 2. Pressure and Density Altitude
Declared Density Charts
Declared conditions are the atmospheric temperature, pressure or density altitudes declared by the Secretary as acceptable for a particular aerodrome for the purpose of determining weight limitations for take off and for landing
They are designed for planning at remote strips without a forecast.
To allow for seasonal variations there are three separate charts
Summer (December to February)
Winter (June to august)
Autumn (march to may)
Spring (September to November)
Charts can be found in CAO Apendix 1, 2 or 3
To use the chart:
Select the appropriate chart for the season
Plot the aerodrome position using latitude and longitude
Read the density altitude correction value off the chart and add to the elevation of the aerodrome

14. 2. Pressure and Density Altitude
For example:
Determine the density height of an aerodrome, elevation 1729ft located at 20s and 141 E in Autumn
Select Spring – autumn chart

15. 2. Pressure and Density Altitude
Plot aerodrome latitude and longitude and read off approximate density altitude correction of 3400ft
Add 3400 to elevation of 1729ft to give declared density height of 5129 ft. You would then use this value for your performance charts.

16. 2. Pressure and Density Altitude
Change in density enroute
Should you be flying and encounter an area or airspace less than the density you are currently in you may experience effects such as:
A higher TAS for the same IAS
Decreases the weight of the fuel to air mixture in the engine resulting in decrease in power
Approx 3% power loss for every 1000ft increase in Density Height
Flying from a high density area to a low density will cause the altimeter to increase and will cause the pilot to want to descend. Apply the saying from “high to low, look out below!”

17. 2. Pressure and Density Altitude
A lower air pressure will decrease the density.
Higher Elevated aerodromes lead to longer take off distances.
A higher air temperature will decrease the density.
Power and aerodynamic performance decrease with decrease in air density.
Decrease in density means higher TAS for a given IAS. Therefore T/O IAS remains constant but TAS increase therefore T/O distance increases.

18. 2. Pressure and Density Altitude
Increase in humidity has the Same effect as lowering density.
If flying in tropics, aim to take off in morning or afternoon when temps are cooler.

19. 3. Factors Affecting Take off performance
The pilot in command of an aircraft must ensure the TODR does not exceed the TODA
When calculating TODR the PIC must take into account:
TORA
Aircraft weight
Pressure altitude of aerodrome
Temperature
Surface
Slope
Wind components

20. 3. Factors Affecting Take off performance
Changes in weight
Increase in weight means greater take off distance
Greater mass, greater inertia, slower acceleration, more distance to reach lift off speeds.
Increase in friction resisting acceleration, more distance.
Increase in weight, increase in stalling speed, increase in TOSS, decrease in climb performance therefore increase TODR.
TOSS
50 ft
Higher TOSS due to higher Vs
50 ft
Increased weight (eg: 10%)
Slower acceleration

21. 3. Factors Affecting Take off performance
Surface
During the take-off roll the largest contributor to drag is friction on the wheels, If this friction is increased take-off distance will increase
50ft
Hard Surface, level and dry
50ft
Long, Wet Grass
50ft
Mud, Sand or water

22. 3. Factors Affecting Take off performance
Slope
If an aircraft is taking-off up-hill it will take longer to accelerate to the take-off safety speed
50ft
Up-slope
If an aircraft is taking-off down-hill it will take less time to accelerate to the take-off safety speed
50ft
Down-slope

23. 3. Factors Affecting Take off performance
Wind
Our take-off safety speed is the Airspeed at which we rotate
An aircraft sitting on the end of the runway with a 20KTS headwind will already have an airspeed of 20KTS, the will reduce the take-off distance required

24. 3. Factors Affecting Take off performance
Wind
Our take-off safety speed is the Airspeed at which we rotate
An aircraft sitting on the end of the runway with a 20KTS headwind will already have an airspeed of 20KTS, the will reduce the take-off distance required
An aircraft with a 20KTS tailwind will require a greater distance to take-off, the increased distance may mean there is no longer sufficient runway to take-off

25. 3. Factors Affecting Take off performance
Flap
Flap lowers the stall speed therefore allows us to rotate at a lower take-off safety speed
Once airborne however the increased drag reduces climb performance
Refer to the flight manual for appropriate flap setting for take-off
50ft
Clean configuration
50ft
Flaps extended

26. 3. Factors Affecting Take off performance
CAO
Subject to paragraph 6.3, the take-off distance required is the distance to accelerate from a standing start with all engines operating and to achieve take-off safety speed at a height of 50 feet above the take-off surface, multiplied by the following factors:
(a) 1.15 for aeroplanes with maximum take-off weights of kg or less;
(b) 1.25 for aeroplanes with maximum take-off weights of kg or greater; or
(c) for aeroplanes with maximum take-off weights between kg and kg, a factor derived by linear interpolation between 1.15 and 1.25 according to the maximum take-off weight of the aeroplane.

27. 3. Factors Affecting Take off performance
CAO
Some tables and charts will factor this in. READ THE CONDITIONS ON THE CHART

28. 4. Calculate Take-Off Perf.
Take Off Performance
For your CPL exams you will be required to calculate take off and landing performance using a variety of different graphs.
The graphs you will need to know how to use are:
Cessna style charts
Piper style charts
Echo charts

29. 4. Calculate Take-Off Perf.
Take Off Performance – Typical Cessna Chart
For Example, calculate the Maximum Take-Off Weight for the following conditions:
Pressure altitude 4000ft
Temperature 25⁰C
Take off Distance Available 800m
Surface long dry grass
No slope
15kt Headwind

30. 4. Calculate Take-Off Perf.
Take Off Performance – Typical Cessna Chart
Method:
Enter the chart with 4000’ on the pressure altitude scale and plot a horizontal line to intersect 25⁰C
From this point plot a vertical line to the TODA of 800m. Also from the intersection of the climb weight limit line draw a horizontal line to the right. This gives us the climb weight limit of 1060kg

31. 4. Calculate Take-Off Perf.
Take Off Performance – Typical Cessna Chart
Method:
From the intersection of the TODA (800m) line plot a horizontal line to the reference line
From the reference line follow the lines in the window to the “Long dry grass” line. Plot a horizontal line from here into the slope graph

32. 4. Calculate Take-Off Perf.
Take Off Performance – Typical Cessna Chart
Method:
From the intersection of the horizontal line and the “Level” line plot a vertical line down into the wind graph to intersect 15kt headwind
From this point plot a horizontal line to the Take Off Weight scale. This gives us the runway performance weight limit of 1000kg

33. 4. Calculate Take-Off Perf.
Take Off Performance – Typical Cessna Chart
Method:
The Maximum Take Off Weight is the lesser of the climb weight limit (1060kg) and the runway performance limit (1000kg)

34. 4. Calculate Take-Off Perf.
Take Off Performance – Typical Piper Chart
For Example, calculate the Take-Off Distance Required for the following conditions:
Pressure altitude 2000ft
Temperature 20⁰C
Surface Long dry grass
2% Down slope
5kt Headwind
Take-Off Weight 1000kg

35. 4. Calculate Take-Off Perf.
Take Off Performance – Typical Piper Chart
Method:
Enter the chart with 25⁰C on the Temperature scale and plot a vertical line up to the Pressure altitude of 2000’. Also check the climb weight limit
From this point plot a horizontal line to the surface reference line. Follow the guide lines to the long dry grass line then proceed horizontally to the slope reference line

36. 4. Calculate Take-Off Perf.
Take Off Performance – Typical Piper Chart
Method:
Follow the guide lines to the 2% down slope line then proceed horizontally to the wind reference line
Follow the guide lines to the 5kt headwind line then proceed horizontally to the take off weight of 1000kg

37. 4. Calculate Take-Off Perf.
Take Off Performance – Typical Piper Chart
Method:
Follow the guide lines to determine the Take-Off Distance Required 750m

38. 4. Calculate Take-Off Perf.
Echo Aircraft Details
The Echo aircraft is an imaginary aircraft invented by CASA for the purpose of assessing students in CPL exams
In the exam you will be supplied with:
Take off performance charts
Landing performance charts
Loading charts

39. 4. Calculate Take-Off Perf.
Take Off Performance – Echo Chart
Question:
Using the echo chart determine the maximum possible take of weight and the take off safety speed for the following conditions.
Aerodrome elevation: 3106ft
Temperature: +15°C
QNH: 1016 hPa
TODA: 680m
Surface: long, wet grass
Slope 2%up
Wind: 5kt Head

40. 4. Calculate Take-Off Perf.
Take Off Performance – Echo Chart
Method:
1. Calculate the pressure height.
= -3hPa
-3hPa x 30 = -90 hPa
PHT = 3106 – 90= 3016ft
2. Enter with 3016ft on the airfield pressure height scale and draw a horizontal line to intersect the +15°C line

41. 4. Calculate Take-Off Perf.
Take Off Performance – Echo Chart
Method:
3. Plot a vertical line to intersect the TODA (680m)
4. Plot a horizontal line to the reference line
5. Follow the guide lines down to the surface type (long wet grass)

42. 4. Calculate Take-Off Perf.
Take Off Performance – Echo Chart
Method:
6. Plot a horizontal line to the slope (2% up)
7. Then a vertical line down to the wind (5kt HWC)
6. From this point draw a horizontal line across the whole box then read off the MTOW (2350kg) and TOSS (87kts)

43. 5. Factors Affecting Landing Performance
The pilot in command of an aircraft must ensure the LDR does not exceed the LDA
When calculating LDR the PIC must take into account:
LDA
Wind
Elevation/Altitude
Aircraft weight
Slope
Surface

44. 5. Factors Affecting Landing Performance
Wind
A headwind reduces our landing distance required due to the reduced groundspeed at touchdown

45. 5. Factors Affecting Landing Performance
Wind
A headwind reduces our landing distance required due to the reduced groundspeed at touchdown
A tailwind increases our landing distance required due to the reduced groundspeed at touchdown

46. 5. Factors Affecting Landing Performance
Slope
If an aircraft is landing up-hill it will take less time to slow down therefore the landing distance will reduce
Up-slope
If an aircraft is landing up-hill it will take more time to slow down therefore the landing distance will increase
Down-slope

47. 5. Factors Affecting Landing Performance
Flap
Flap lowers the stall speed therefore allowing us to land at a lower approach speed, reducing our landing distance
Clean configuration
Flaps extended

48. 5. Factors Affecting Landing Performance
Runway Surface
A low friction surface will not allow efficient braking to occur and landing distance will increase.
Aquaplaning is the phenomenon of a tyre skating along a thin film of water and not rotating, even though its free to do so. Wheel braking therefore has no effect.
This most likely at higher ground speeds. The speed at which aquaplaning occurs can be calculated as follows:
9 X Take−off tyre pressure

49. 5. Factors Affecting Landing Performance
CAO
Subject to paragraphs 10.3 and 10.4, an aeroplane must not land unless the landing distance available is equal to or greater than the distance required to bring the aeroplane to a complete stop or, in the case of aeroplanes operated on water, to a speed of 3 knots, following an approach to land at a speed not less than 1.3VS maintained to within 50 feet of the landing surface. This distance is to be measured from the point where the aeroplane first reaches a height of 50 feet above the landing surface and must be multiplied by the following factors:
(a) 1.15 for aeroplanes with maximum take-off weights of kg or less;
(b) 1.43 for aeroplanes with maximum take-off weights of kg or greater;
(c) for aeroplanes with maximum take-off weights between kg and 4500 kg, a factor derived by linear interpolation between 1.15 and 1.43 according to the maximum take-off weight of the aeroplane.

50. 5. Factors Affecting Landing Performance
CAO
Some tables and charts will factor this in. READ THE CONDITIONS ON THE CHART

51. 6. Calculate Landing Perf.
Landing Performance – Typical Cessna Chart
For Example, calculate the Landing Distance Required and Maximum Landing Weight for the following conditions:
Pressure altitude 7000ft
Temperature 15⁰C
No slope
10kt Headwind

52. 6. Calculate Landing Perf.
Landing Performance – Typical Cessna Chart
Method:
Enter the chart with 7000’ on the pressure altitude scale and plot a horizontal line to intersect 15⁰C
From this point plot a vertical line into the Landing Distance Required Window

53. 6. Calculate Landing Perf.
Landing Performance – Typical Cessna Chart
Method:
Enter the chart again from the wind component of 10kts and plot a vertical line up to the slope, in this case level
From this point plot a horizontal line to intersect the vertical line already in the Landing Distance Required window

54. 6. Calculate Landing Perf.
Landing Performance – Typical Cessna Chart
Method:
Follow the guide lines to the left to determine the Landing Distance Required 550m
We also need to check the climb weight limit – in case of a Go-Around – In the climb weight limit window plot a horizontal line from pressure height to the reference line then straight down to read the climb weight limit of 910kg

55. 6. Calculate Take-Off Perf.
Landing Performance – Typical Piper Chart
For Example, calculate the Landing Distance Required for the following conditions:
Pressure altitude 4000ft
Temperature 30⁰C
2% Down slope
10kt Headwind

56. 6. Calculate Take-Off Perf.
Landing Performance – Typical Piper Chart
For Example, calculate the Landing Distance Required for the following conditions:
Pressure altitude 4000ft
Temperature 30⁰C
2% Down slope
10kt Headwind

57. 6. Calculate Take-Off Perf.
Take Off Performance – Typical Piper Chart
Method:
Enter the chart with 30⁰C on the Temperature scale and plot a vertical line up to the Pressure altitude of 4000’. Also check the climb weight limit
From this point plot a horizontal line to the slope reference line. Follow the guide lines to the 2% down slope line then horizontally across to the wind reference line
No climb weight limit with a pressure alt. of 4000’

58. 6. Calculate Take-Off Perf.
Take Off Performance – Typical Piper Chart
Method:
Follow the guide lines to the 10kt headwind line then proceeded horizontally to read the Landing Distance Required of 690m
No climb weight limit with a pressure alt. of 4000’

59. 4. Calculate Take-Off Perf.
Landing Performance – Echo Chart
Question:
Using the echo chart determine the maximum possible landing weight and the approach speed for the following conditions.
Aerodrome elevation: 1410ft
Temperature: +30°C
QNH: 1010 hPa
TODA: 850m
Slope 1%down
Wind: 5kt Head

60. 4. Calculate Take-Off Perf.
Landing Performance – Echo Chart
Method:
1: Calculate the pressure height.
= 3hPa
3hPa x 30 = 90 hPa
Aerodrome elevation = = 1500ft

61. 6. Calculate Take-Off Perf.
Take Off Performance – Echo Chart
Method:
1.Draw a line from Pressure Height of 1500ft to 30C line.

62. 6. Calculate Take-Off Perf.
Take Off Performance – Echo Chart
Method:
2.Draw a line vertically up to an LDA of 850m

63. 6. Calculate Take-Off Perf.
Take Off Performance – Echo Chart
Method:
3.Draw a line horizontally to 1% down slope

64. 6. Calculate Take-Off Perf.
Take Off Performance – Echo Chart
Method:
4.Draw a line vertically down to 5kt headwind

65. 6. Calculate Take-Off Perf.
Take Off Performance – Echo Chart
Method:
Draw a line horizontally to the right to work out approach speed of 84kts
And to the left to work out Landing weight of 2350kg

66. Questions?