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

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Presentation on theme: "Performance ATC Chapter 2. Aim To determine take-off and landing distances using flight manual data and the factors that affect it."— Presentation transcript:

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 1.State terms and definitions 2.Calculate Pressure and Density altitudes 3.State factors affecting take-off performance 4.Calculate take-off distance required 5.State factors affecting landing performance 6.Calculate landing distance required

4 1. Terms and Definitions TORR TODR Screen Height 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 Take-Off Run Required (TORR) Actual Ground Run Required 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

5 TORA TODA Screen Height Take-Off Distance Available (TODA) Length of take-off run available plus any clear way 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 Clearway 1. Terms and Definitions

6 ASDA 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 1. Terms and Definitions

7 LRR LDR 50’ Landing Distance Available (LDA) Length of runway suitable for the ground roll of an aircraft beginning at the threshold or displaced threshold Landing Run Required (LRR) Actual Ground Roll Required 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 LDA 1. Terms and Definitions

8 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 2. Pressure and Density Altitude

9 Pressure Altitude 1.Determine pressure variation from ISA 1013 hPa – 996 hPa = 17hPa 2.Multiply variation by the pressure lapse rate, 30ft per 1 hPa 17 hPa x 30ft = 510ft 3.Apply the variation to the aircrafts altitude Since QNH is less than ISA, pressure altitude will be higher =5010 Aircraft is flying at 4500ft AMSL QNH is 996 hPa Temperature is 30⁰C What is the pressure altitude? 2. Pressure and Density Altitude

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

11 Density Altitude Pressure altitude is 4000ft QNH is 1020 hPa Temperature is 22⁰C What is the density altitude? 1.Determine temperature variation from ISA at the pressure altitude 15 ⁰C - (2x4)= 7 ⁰C 2.Multiply variation by the lapse rate, 120ft per 1⁰C 22⁰C - 7 ⁰C = 15 ⁰C x 120ft = 3300ft 3.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 2. Pressure and Density Altitude

12 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 Std. pressure 1013hPa +15 x 30ft/hPa = 450ft Aerodrome Elevation = 2550 ft MSL QNH 998 hPa Pressure height = =3000ft 2. Pressure and Density Altitude

13 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: 1.Select the appropriate chart for the season 2.Plot the aerodrome position using latitude and longitude 3.Read the density altitude correction value off the chart and add to the elevation of the aerodrome 2. Pressure and Density Altitude

14 For example: Determine the density height of an aerodrome, elevation 1729ft located at 20s and 141 E in Autumn 1.Select Spring – autumn chart 2. Pressure and Density Altitude

15 2.Plot aerodrome latitude and longitude and read off approximate density altitude correction of 3400ft 3.Add 3400 to elevation of 1729ft to give declared density height of 5129 ft. You would then use this value for your performance charts. 2. Pressure and Density Altitude

16 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!” 2. Pressure and Density Altitude Change in density enroute

17 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. 2. Pressure and Density Altitude

18 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. 2. Pressure and Density Altitude

19 Take-Off 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 3. Factors Affecting Take off performance

20 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. Changes in weight Increased weight (eg: 10%) Slower acceleration 50 ft TOSS Higher TOSS due to higher Vs 3. Factors Affecting Take off performance

21 Hard Surface, level and dry Long, Wet Grass Mud, Sand or water 50ft 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 3. Factors Affecting Take off performance 50ft

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

23 Wind 3. Factors Affecting Take off performance 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 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 3. Factors Affecting Take off performance

25 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 3. Factors Affecting Take off performance 50ft Clean configuration 50ft Flaps extended

26 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. 3. Factors Affecting Take off performance

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

28 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 4. Calculate Take-Off Perf.

29 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 Take Off Performance – Typical Cessna Chart

30 4. Calculate Take-Off Perf. Method: 1.Enter the chart with 4000’ on the pressure altitude scale and plot a horizontal line to intersect 25⁰C 2.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 Take Off Performance – Typical Cessna Chart

31 4. Calculate Take-Off Perf. Method: 3.From the intersection of the TODA (800m) line plot a horizontal line to the reference line 4.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 Take Off Performance – Typical Cessna Chart

32 4. Calculate Take-Off Perf. Method: 5.From the intersection of the horizontal line and the “Level” line plot a vertical line down into the wind graph to intersect 15kt headwind 6.From this point plot a horizontal line to the Take Off Weight scale. This gives us the runway performance weight limit of 1000kg Take Off Performance – Typical Cessna Chart

33 4. Calculate Take-Off Perf. Method: 7.The Maximum Take Off Weight is the lesser of the climb weight limit (1060kg) and the runway performance limit (1000kg) Take Off Performance – Typical Cessna Chart

34 4. Calculate Take-Off Perf. 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 Take Off Performance – Typical Piper Chart

35 4. Calculate Take-Off Perf. Method: Take Off Performance – Typical Piper Chart 1.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 2.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. Method: Take Off Performance – Typical Piper Chart 3.Follow the guide lines to the 2% down slope line then proceed horizontally to the wind reference line 4.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. Method: Take Off Performance – Typical Piper Chart 5.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. Question: Take Off Performance – Echo Chart 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. Method: Take Off Performance – Echo Chart 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. Method: Take Off Performance – Echo Chart 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. Method: Take Off Performance – Echo Chart 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 Landing

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

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

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

48 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: Runway Surface 5. Factors Affecting Landing Performance

49 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. 5. Factors Affecting Landing Performance

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

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

52 6. Calculate Landing Perf. Method: 1.Enter the chart with 7000’ on the pressure altitude scale and plot a horizontal line to intersect 15⁰C 2.From this point plot a vertical line into the Landing Distance Required Window Landing Performance – Typical Cessna Chart

53 6. Calculate Landing Perf. Method: 3.Enter the chart again from the wind component of 10kts and plot a vertical line up to the slope, in this case level 4.From this point plot a horizontal line to intersect the vertical line already in the Landing Distance Required window Landing Performance – Typical Cessna Chart

54 6. Calculate Landing Perf. Method: 5.Follow the guide lines to the left to determine the Landing Distance Required 550m 6.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 Landing Performance – Typical Cessna Chart

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

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

57 6. Calculate Take-Off Perf. Method: Take Off Performance – Typical Piper Chart 1.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 2.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. Method: Take Off Performance – Typical Piper Chart 3.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. Question: Landing Performance – Echo Chart 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. Method: Landing Performance – Echo Chart 1: Calculate the pressure height = 3hPa 3hPa x 30 = 90 hPa Aerodrome elevation = = 1500ft

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

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

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

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

65 6. Calculate Take-Off Perf. Method: Take Off Performance – Echo Chart 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?


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