B737-Reduced_Thrust_Considerations

民航发表于 2010-4-5 01:26:05

B737-Reduced_Thrust_Considerations
 
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民航发表于 2010-4-5 01:26:19

737.1 Reduced Thrust Considerations Taakkeeooffff Peerrffoorrmaanccee Maarrggiinss Dick Mayward Flight Operations Engineering Boeing Commercial Airplanes May 2004 The Boeing Company 737.2 Common Misconceptions • “If reduced thrust is used, then the airplane will not be able to clear the obstacles if an engine fails during takeoff.” • “If the maximum allowable assumed temperature is used, then there will be no stopping margin left if the takeoff is aborted.” The Boeing Company 737.3 Regulatory Compliance Boeing AFM states: “Operations at reduced takeoff thrust based on an assumed temperature higher than the actual ambient temperature is permissible if the airplane meets ALL applicable performance requirements at the planned takeoff weight and reduced thrust setting.” AC//AMJJ 2255--1133 The Boeing Company 737.4 Regulatory Performance Requirements • Have sufficient runway length for: – 115% of all-engine takeoff distance – One engine inoperative takeoff distance – Accelerate-stop distance • Achieve the one engine inoperative minimum climb gradient for: – First segment – Second segment – Final segment • Clear all obstacles in the intended takeoff flight path The Boeing Company 737.5 Effect of Temperature on True Airspeed and Thrust • Air density is lower at higher outside air temperature (OAT) • For a given indicated airspeed (IAS), true airspeed (TAS) is higher at higher OAT • For a given reduced engine power setting (N1 or EPR), lower air density (higher OAT) results in lower thrust The Boeing Company 737.6 The Assumed Temperature Method • Dispatch takeoff performance must assume the higher true airspeed at the assumed higher temperature • Takeoff thrust assumed is the rated thrust at that assumed temperature The Boeing Company 737.7 Inherent Conservatism of the Assumed Temperature Method • The actual thrust will be higher than the rated thrust at the assumed temperature, because the actual air density is higher • The actual true airspeed will be lower, because the actual ambient temperature is lower • The lower true airspeed combined with the higher thrust will result in a shorter ground distance The Boeing Company 737.8 The True Airspeed Effect 148 146 144 142 140 True airspeed, kt Assumed ttemperratturre,, °C OAT – assumed temperature difference Assumed true airspeed Actual true airspeed at OAT, 15°C 30 32 34 36 38 40 The Boeing Company 737.9 737-800W WITH CFM56-7B27 ENGINES PRESSURE ALTITUDE 0 FT RUNWAY LENGTH 7000 FT, DRY NO OBSTACLES FLAPS 5, A/C AUTO, STANDARD TAKEOFF SPEEDS MAXIMUM RATED THRUST (27K) 24K DERATE OAT (C) MTOW (KG) PERF LIM V1 V R V2 (KT) MTOW (KG) PERF LIM V1 V R V2 (KT) 60 60400 FLD 134 135 140 55900 FLD 131 131 134 55 62200 FLD 136 137 142 57700 FLD 133 133 137 50 65000 FLD 138 139 146 59700 FLD 134 135 139 45 67200 FLD 140 141 148 61900 FLD 136 137 142 40 69300 FLD 141 143 150 64100 FLD 138 139 144 38 70300 FLD 142 144 151 65000 FLD 139 140 145 36 71100 FLD 142 145 152 65800 FLD 139 141 146 34 72000 FLD 143 145 153 66700 FLD 140 141 147 32 72900 FLD 143 146 154 67700 FLD 141 142 148 30 73700 FLD 144 147 155 68600 FLD 141 143 149 25 74300 FLD 144 147 156 69200 FLD 142 144 150 20 75000 FLD 145 148 156 69800 FLD 143 144 151 15 75600 FLD 146 149 157 70300 FLD 144 145 151 10 76200 FLD 146 149 157 71000 FLD 144 146 152 Maximum Allowable Assumed Temperature 38°C 27K, OAT 15°C Takeoff Weight 70300 KG The Assumed Temperature Method The Boeing Company 737.10 Margins Between Assumed and Actual Performance at the Maximum Allowable Assumed Temperature Parameter V1 (KIAS / KTAS) VR (KIAS / KTAS) V2 (KIAS / KTAS) Thrust per engine at V1, lb Thrust per engine at VR, lb Thrust per engine at V2, lb One engine inoperative takeoff distance, ft Accelerate-stop distance, ft 115% all-engine takeoff distance, ft OAT 38°C OAT 15°C assume 38°C Extra margin 142 / 148 144 / 150 151 / 157 23855 19833 19857 7000 7000 6942 142 / 142 144 / 144 151 / 151 24061 20019 20034 6507 6507 6464 6 6 6 206 186 177 493 493 478 The Boeing Company 737.11 6800 6600 6400 6200 6000 Field length, ft Assumed ttemperratturre,, °C Runway length Actual balanced field length 30 32 34 36 38 40 Field Length Margin Increases With Lower Assumed Temperature Due to Higher Thrust • 737-800W / CFM56-7B27 • Pressure Altitude 0 ft • Runway Length 7000 ft, Dry • Flaps 5, Standard Takeoff Speeds • OAT 15°C, Takeoff Weight 70300 kg 7200 7000 28 Fiieelldd Leennggtthh Maarrggiinn 875 ft 493 ft The Boeing Company 737.12 25500 25000 24500 24000 23500 Net thrust/ engine at V1, lb Assumed ttemperratturre,, °C Rated thrust Actual thrust 30 32 34 36 38 40 Thrust Margin Decreases With Lower Assumed Temperature 26000 28 Raatteedd Thhrruusstt Veerrssuuss Accttuuaall Thhrruusstt • 737-800W / CFM56-7B27 • Pressure Altitude 0 ft • Runway Length 7000 ft, Dry • Flaps 5, Standard Takeoff Speeds • OAT 15°C, Takeoff Weight 70300 kg 206 llb 139 llb The Boeing Company 737.13 737-800W W ITH CFM56-7B27 ENGINES PRESSURE ALTITUDE 0 FT RUNWAY LENGTH 7000 FT, DRY NO OBSTACLES FLAPS 5, A/C AUTO, STANDARD TAKEOFF SPEEDS MAXIMUM RATED THRUST (27K) 24K DERATE OAT (C) MTOW (KG) PERF LIM V1 VR V2 (KT) MTOW (KG) PERF LIM V1 VR V2 (KT) 60 60400 FLD 134 135 140 55900 FLD 131 131 134 55 62200 FLD 136 137 142 57700 FLD 133 133 137 50 65000 FLD 138 139 146 59700 FLD 134 135 139 45 67200 FLD 140 141 148 61900 FLD 136 137 142 40 69300 FLD 141 143 150 64100 FLD 138 139 144 38 70300 FLD 142 144 151 65000 FLD 139 140 145 36 71100 FLD 142 145 152 65800 FLD 139 141 146 34 72000 FLD 143 145 153 66700 FLD 140 141 147 32 72900 FLD 143 146 154 67700 FLD 141 142 148 30 73700 FLD 144 147 155 68600 FLD 141 143 149 25 74300 FLD 144 147 156 69200 FLD 142 144 150 20 75000 FLD 145 148 156 69800 FLD 143 144 151 15 75600 FLD 146 149 157 70300 FLD 144 145 151 10 76200 FLD 146 149 157 71000 FLD 144 146 152 Lower Takeoff Weight May Permit Higher Maximum Allowable Assumed Temperature The Boeing Company 737.14 145 140 135 130 True airspeed, kt Assumed ttemperratturre,, °C Assumed true airspeed Actual true airspeed at OAT 40 45 50 55 60 65 True Airspeed Effect Increases With Higher Assumed Temperature 150 35 6 kt 10 kt Trruuee Aiirrssppeeeedd Effffeecctt The Boeing Company 737.15 22000 21000 20000 19000 18000 Net thrust/ engine at V1, lb Assumed ttemperratturre,, °C Rated thrust Actual thrust 40 45 50 55 60 65 Thrust Margin Increases With Higher Assumed Temperature 23000 35 650 llb • 737-800W / CFM56-7B27 • Pressure Altitude 0 ft, OAT 15°C • Runway Length 7000 ft, Dry • Flaps 5, Standard Takeoff Speeds 24000 206 llb 25000 Raatteedd Thhrruusstt Veerrssuuss Accttuuaall Thhrruusstt The Boeing Company 737.16 • 737-800W / CFM56-7B27 • Pressure Altitude 0 ft, OAT 15°C • Runway Length 7000 ft, Dry • Flaps 5, Standard Takeoff Speeds 6600 6400 6200 6000 5800 Field length, ft Assumed ttemperratturre,, °C Runway length Actual balanced field length 40 45 50 55 60 65 Field Length Margin Due to the True Airspeed Effect Increases With Higher Assumed Temperature 6800 35 493 ft 1035 ft 7200 7000 Fiieelldd Leennggtthh Maarrggiinn The Boeing Company 737.17 • If performance is limited by the one engine inoperative minimum climb gradient requirements, the higher actual thrust will result in a higher climb gradient • If performance is limited by obstacle clearance, the higher climb gradient combined with the shorter takeoff distance will result in extra clearance margin Extra obstacle clearance margins Performance Margins in Flight Path With Assumed Temperature Reduced Thrust Actual thrust and climb gradient Rated thrust at the assumed temp The Boeing Company 737.18 737-800W W ITH CFM56-7B27 ENGINES PRESSURE ALTITUDE 5000 FT RUNWAY LENGTH 12000 FT, DRY NO OBSTACLES FLAPS 5, A/C AUTO, STANDARD TAKEOFF SPEEDS MAXIMUM RATED THRUST (27K) 24K DERATE OAT (C) MTOW (KG) PERF LIM V1 VR V2 (KT) MTOW (KG) PERF LIM V1 VR V2 (KT) 60 57300 CLB 133 133 136 49300 CLB 124 124 126 55 59900 CLB 136 136 139 51500 CLB 126 126 129 50 62500 CLB 138 139 142 53800 CLB 129 129 132 45 65100 CLB 141 141 145 56200 CLB 132 132 134 40 68100 CLB 143 144 148 58900 CLB 135 135 138 35 71000 CLB 146 147 151 61700 CLB 138 138 141 30 73900 CLB 148 150 154 64600 CLB 140 141 144 25 75400 CLB 149 151 155 67600 CLB 143 144 147 20 76400 CLB 150 152 156 70800 CLB 146 147 151 15 76400 CLB 150 152 156 70900 CLB 146 147 151 10 76500 CLB 150 152 156 71000 CLB 146 147 151 27K, OAT 10°C Takeoff Weight 71000 KG Maximum Allowable Assumed Temperature 35°C Thrust And Climb Gradient Margins At The Maximum Allowable Assumed Temperature Parameter Thrust per engine at V2, lb One engine inoperative climb gradient, % OAT 35°C OAT 10°C assume 35°C Extra margin 20108 2.4 20355 2.54 247 0.14 The Boeing Company 737.19 • 737-800W / CFM56-7B27 • Pressure Altitude 5000 ft • Runway Length 12000 ft, Dry • Flaps 5, Standard Takeoff Speeds • OAT 10°C, Takeoff Weight 71000 kg 2..8 2..6 2..4 2..2 Climb gradient , % Assumed ttemperratturre,, °C Regulatory minimum Actual gradient 20 25 30 35 40 3..0 15 3..4 3..2 Climb Gradient Increases With Lower Assumed Temperature Due to Higher Thrust 0.9 % Clliimbb Grraaddiieenntt Maarrggiinn 0.14 % The Boeing Company 737.20 737-800W WITH CFM56-7B27 ENGINES PRESSURE ALTITUDE 5000 FT RUNWAY LENGTH 12000 FT, DRY NO OBSTACLES FLAPS 5, A/C AUTO, STANDARD TAKEOFF SPEEDS MAXIMUM RATED THRUST (27K) 24K DERATE OAT (C) MTOW (KG) PERF LIM V1 VR V2 (KT) MTOW (KG) PERF LIM V1 VR V2 (KT) 60 57300 CLB 133 133 136 49300 CLB 124 124 126 55 59900 CLB 136 136 139 51500 CLB 126 126 129 50 62500 CLB 138 139 142 53800 CLB 129 129 132 45 65100 CLB 141 141 145 56200 CLB 132 132 134 40 68100 CLB 143 144 148 58900 CLB 135 135 138 35 71000 CLB 146 147 151 61700 CLB 138 138 141 30 73900 CLB 148 150 154 64600 CLB 140 141 144 25 75400 CLB 149 151 155 67600 CLB 143 144 147 20 76400 CLB 150 152 156 70800 CLB 146 147 151 15 76400 CLB 150 152 156 70900 CLB 146 147 151 10 76500 CLB 150 152 156 71000 CLB 146 147 151 Lower Takeoff Weight May Permit A Higher Maximum Allowable Assumed Temperature The Boeing Company 737.21 • 737-800W / CFM56-7B27 • Pressure Altitude 5000 ft, OAT 10°C • Runway Length 12000 ft, Dry • Flaps 5, Standard Takeoff Speeds Climb gradient , % Assumed ttemperratturre,, °C 30 35 40 45 50 55 Climb Gradient Margin Due to the True Airspeed Effect Increases With Higher Assumed Temperature 60 65 2..6 2..4 Regulatory minimum Actual gradient 0.25 % 0.14 % 2..3 2..5 2..7 Clliimbb Grraaddiieenntt Maarrggiinn The Boeing Company 737.22 737-800W WITH CFM56-7B27 ENGINES PRESSURE ALTITUDE 0 FT RUNWAY 9000 FT, DRY OBSTACLE: 50 FT HT AT 1000 FT DIST FROM LIFTOFF END FLAPS 5, A/C AUTO, STANDARD TAKEOFF SPEEDS MAXIMUM RATED THRUST (27K) 24K DERATE OAT (C) MTOW (KG) PERF LIM V1 VR V2 (KT) MTOW (KG) PERF LIM V1 VR V2 (KT) 60 62900 OBS 138 138 143 57000 OBS 132 132 136 55 65200 OBS 140 141 145 59200 OBS 134 134 138 50 68600 OBS 142 144 149 61600 OBS 137 137 141 45 71300 OBS 144 146 152 64200 OBS 139 140 144 43 72400 OBS 145 147 153 65200 OBS 140 141 145 41 73500 OBS 146 148 154 66300 OBS 141 142 146 39 74600 OBS 147 149 155 67400 OBS 142 143 148 37 75700 OBS 147 150 156 68400 OBS 143 144 149 35 76700 OBS 148 151 157 69400 OBS 143 145 150 30 79300 OBS 149 153 160 72200 OBS 146 147 153 25 79800 OBS 150 153 160 72700 OBS 146 147 153 20 80300 OBS 150 154 161 73100 OBS 147 148 153 15 80800 OBS 151 154 161 73500 OBS 147 148 154 10 81300 OBS 151 155 161 73900 OBS 147 149 154 Maximum Allowable Assumed Temperature 41°C 27K, OAT 15°C Takeoff Weight 73500 KG Obstacle Clearance Margin at the Maximum Allowable Assumed Temperature Parameter Net clearance OAT 41°C OAT 15°C assume 41°C Extra margin 35 ft 61 ft 26 ft The Boeing Company 737.23 • 737-800W / CFM56-7B27 • Pressure Altitude 0 ft • Runway Length 9000 ft, Dry • Obstacle: 50 ft Ht at 1000 ft Dist from liftoff end • Flaps 5, Standard Takeoff Speeds • OAT 15°C, Takeoff Weight 73500 kg 80 60 40 20 Net clearance, ft Assumed ttemperratturre,, °C Regulatory minimum Actual net clearance 30 32 34 36 38 100 28 120 Obbssttaaccllee Clleeaarraannccee Maarrggiinn Net Clearance Margin Increases With Lower Assumed Temperature Due to Higher Thrust 26 ft 81 ft 40 42 The Boeing Company 737.24 737-800W WITH CFM56-7B27 ENGINES PRESSURE ALTITUDE 0 FT RUNWAY 9000 FT, DRY OBSTACLE: 50 FT HT AT 1000 FT DIST FROM LIFTOFF END FLAPS 5, A/C AUTO, STANDARD TAKEOFF SPEEDS MAXIMUM RATED THRUST (27K) 24K DERATE OAT (C) MTOW (KG) PERF LIM V1 VR V2 (KT) MTOW (KG) PERF LIM V1 VR V2 (KT) 60 62900 OBS 138 138 143 57000 OBS 132 132 136 55 65200 OBS 140 141 145 59200 OBS 134 134 138 50 68600 OBS 142 144 149 61600 OBS 137 137 141 45 71300 OBS 144 146 152 64200 OBS 139 140 144 43 72400 OBS 145 147 153 65200 OBS 140 141 145 41 73500 OBS 146 148 154 66300 OBS 141 142 146 39 74600 OBS 147 149 155 67400 OBS 142 143 148 37 75700 OBS 147 150 156 68400 OBS 143 144 149 35 76700 OBS 148 151 157 69400 OBS 143 145 150 30 79300 OBS 149 153 160 72200 OBS 146 147 153 25 79800 OBS 150 153 160 72700 OBS 146 147 153 20 80300 OBS 150 154 161 73100 OBS 147 148 153 15 80800 OBS 151 154 161 73500 OBS 147 148 154 10 81300 OBS 151 155 161 73900 OBS 147 149 154 Lower Takeoff Weight May Permit Higher Maximum Allowable Assumed Temperature The Boeing Company 737.25 • 737-800W / CFM56-7B27 • Pressure Altitude 0 ft, OAT 15°C • Runway Length 9000 ft, Dry • Obstacle: 50 ft Ht at 1000 ft Dist from liftoff end • Flaps 5, Standard Takeoff Speeds 60 40 20 Net clearance, ft Assumed ttemperratturre,, °C Regulatory minimum Actual net clearance 40 45 50 55 60 80 Obbssttaaccllee Clleeaarraannccee Maarrggiinn 65 Net Clearance Margin Due to True Airspeed Effect Increases With Higher Assumed Temperature 58 ft 69 ft The Boeing Company 737.26 Issues With Takeoff Speeds • Standard takeoff speeds depend on: – Takeoff weight – Flap setting – Thrust (temperature, pressure altitude, and engine bleed configuration) – V1 also depends on runway slope, wind, and surface condition (dry or wet) • Takeoff speeds vary with thrust, therefore, they vary with assumed temperature The Boeing Company 737.27 Increasing V1 and VR, typically resulting in lower V2, will re-balance field length V1 = 140 VR = 145 V2 = 150 Lower thrust Proper takeoff speeds for a balanced field length V2 = 155 Higher thrust V1 = 135 VR = 140 Effect of Thrust on Takeoff Speeds (IAS) The Boeing Company 737.28 • 737-800W / CFM56-7B27 • Pressure Altitude 0 ft • Flaps 5, Dry Runway, Standard Speeds • OAT 15°C, Takeoff Weight 60400 kg 140 135 130 125 Takeoff speeds, KIAS Assumed ttemperratturre,, °C V1 VR 25 30 35 40 45 50 145 Thhrruusstt Effffeecctt oonn Taakkeeooffff SSppeeeeddss 55 60 Takeoff Speeds (IAS) Vary With Assumed Temperature V2 65 The Boeing Company 737.29 Use the FMC or QRH to Obtain Proper Standard Takeoff Speeds T A K E O F F R E F 1 / 2 F L A P S ° 2 6 K N 1 98. 8 / 98.8% C G TRIM 22.5% 5 . 2 5 RUNW A Y Q R H V 1 V R V 2 G W / T O W S E L E C T QRH OFF> — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — Standard Takeoff Speeds Only Standard takeoff speeds, plus adjustments for clearway and stopway, slippery and contaminated runways, and inoperative system. No optimized V1 or improved climb. Quick Reference Handbook The Boeing Company 737.30 737-800W WITH CFM56-7B27 ENGINES PRESSURE ALTITUDE 0 FT RUNWAY LENGTH 7000 FT, DRY NO OBSTACLES FLAPS 5, A/C AUTO, STANDARD TAKEOFF SPEEDS MAXIMUM RATED THRUST (27K) 24K DERATE OAT (C) MTOW (KG) PERF LIM V1 VR V2 (KT) MTOW (KG) PERF LIM V1 VR V2 (KT) 60 60400 FLD 134 135 140 55900 FLD 131 131 134 55 62200 FLD 136 137 142 57700 FLD 133 133 137 50 65000 FLD 138 139 146 59700 FLD 134 135 139 45 67200 FLD 140 141 148 61900 FLD 136 137 142 40 69300 FLD 141 143 150 64100 FLD 138 139 144 38 70300 FLD 142 144 151 65000 FLD 139 140 145 36 71100 FLD 142 145 152 65800 FLD 139 141 146 34 72000 FLD 143 145 153 66700 FLD 140 141 147 32 72900 FLD 143 146 154 67700 FLD 141 142 148 30 73700 FLD 144 147 155 68600 FLD 141 143 149 25 74300 FLD 144 147 156 69200 FLD 142 144 150 20 75000 FLD 145 148 156 69800 FLD 143 144 151 15 75600 FLD 146 149 157 70300 FLD 144 145 151 10 76200 FLD 146 149 157 71000 FLD 144 146 152 27K, OAT 15°C Takeoff Weight 60400 KG Maximum Allowable Assumed Temperature 60°C Overspeed Use Speeds for the Maximum Allowable Assumed Temperature, Ignoring Thrust Effect on Speeds The Boeing Company 737.31 737-800W / CFM56-7B27 Pressure Altitude 0 ft, OAT 15°C Dry Runway, Standard Speeds Flaps 5, Takeoff Weight 60400 kg 15°C 128 / 131 / 143 45°C 131 / 133 / 142 60°C 134 / 135 / 140 V1 / VR / V2 (kt) Assumed temperature Proper Takeoff Speeds From QRH The Boeing Company 737.32 737-800W WITH CFM56-7B27 ENGINES PRESSURE ALTITUDE 0 FT RUNWAY LENGTH 7000 FT, DRY NO OBSTACLES FLAPS 5, A/C AUTO, STANDARD TAKEOFF SPEEDS MAXIMUM RATED THRUST (27K) 24K DERATE OAT (C) MTOW (KG) PERF LIM V1 VR V2 (KT) MTOW (KG) PERF LIM V1 VR V2 (KT) 60 60400 FLD 134 135 140 55900 FLD 131 131 134 55 62200 FLD 136 137 142 57700 FLD 133 133 137 50 65000 FLD 138 139 146 59700 FLD 134 135 139 45 67200 FLD 140 141 148 61900 FLD 136 137 142 40 69300 FLD 141 143 150 64100 FLD 138 139 144 38 70300 FLD 142 144 151 65000 FLD 139 140 145 36 71100 FLD 142 145 152 65800 FLD 139 141 146 34 72000 FLD 143 145 153 66700 FLD 140 141 147 32 72900 FLD 143 146 154 67700 FLD 141 142 148 30 73700 FLD 144 147 155 68600 FLD 141 143 149 25 74300 FLD 144 147 156 69200 FLD 142 144 150 20 75000 FLD 145 148 156 69800 FLD 143 144 151 15 75600 FLD 146 149 157 70300 FLD 144 145 151 10 76200 FLD 146 149 157 71000 FLD 144 146 152 27K, OAT 15°C Takeoff Weight 60400 KG Maximum Allowable Assumed Temperature 60°C Overspeed Use Speeds for the Lower Assumed Temperature, Ignoring Weight Effect on Speeds The Boeing Company 737.33 6000 6200 6400 6600 6800 7000 7200 28 30 32 34 36 38 40 • 737-800W / CFM56-7B27 • Pressure Altitude 0 ft, OAT 15°C • Runway Length 7000 ft, Dry • Flaps 5, Takeoff Weight 70300 kg • Max Allowable Assumed Temp 38°C Field length, ft Fiieelldd Leennggtthh Maarrggiinn Wiitthh Ovveerrssppeeeedd Overspeed Reduces Field Length Margin Proper speeds Runway length available Overspeed – Max assumed temp Overspeed – Lower assumed temp Assumed ttemperratturre,, °°C The Boeing Company 737.34 • 737-800W / CFM56-7B27 • Pressure Altitude 5000 ft, OAT 10°C • Runway Length 12000 ft, Dry • Flaps 5, Takeoff Weight 71000 kg • Max Allowable Assumed Temp 35°C Climb gradient, % Clliimbb Grraaddiieenntt Maarrggiinn Wiitthh Ovveerrssppeeeedd Proper speeds Regulatory minimum Effect of Overspeed on Climb Gradient 2..2 2..4 2..6 2..8 3..0 3..2 3..4 3..6 15 20 25 30 35 40 Assumed ttemperratturre,, °°C Overspeed – Lower assumed temp Overspeed – Max assumed temp The Boeing Company 737.35 • 737-800W / CFM56-7B27 • Pressure Altitude 0 ft, OAT 15°C • Runway Length 9000 ft, Dry • Obstacle: 50 ft Ht at 1000 ft Dist from liftoff end • Flaps 5, Takeoff Weight 73500 kg • Max Allowable Assumed Temp 41°C Net clearance , ft Assumed ttemperratturre,, °°C Obbssttaaccllee Clleeaarraannccee Wiitthh Ovveerrssppeeeedd Overspeed Reduces Obstacle Clearance Margin 20 40 60 80 100 120 28 30 32 34 36 38 40 42 Proper speeds Regulatory minimum Overspeed – Max assumed temp Overspeed – Lower assumed temp The Boeing Company 737.36 Means to Maximize Thrust Reduction and Performance Margins • Takeoff configuration: – Flaps setting selection – No engine bleed for A/C packs • Takeoff speeds options: – Improved climb – Optimized V1 (unbalanced) • Goal: Increase the difference between the OAT and the assumed temperature, thus increasing the true airspeed effect. The Boeing Company 737.37 7 3 7 -80 0W W ITH C FM 56 -7B 2 7 ENG IN E S PR ESSURE A LT ITUDE 0 FT R U NW A Y LE N G T H 7 0 0 0 F T , D R Y NO O BSTACLES 27K , STANDARD TAKEO FF S P EED S O AT (C ) FLA P S 5 A /C A U TO FLA P S 15 A /C A U TO FLA P S 5 A /C O FF 60 60400 6 0 800 6 1 300 55 62200 6 3 400 6 3 200 50 65000 6 6 100 6 6 000 45 67200 6 8 200 6 8 100 40 69300 7 0 500 7 0 300 38 70300 7 1 400 7 1 100 36 71100 7 2 300 7 2 000 34 72000 7 3 200 7 2 800 32 72900 7 4 100 7 3 600 30 73700 7 5 000 7 4 400 25 74300 7 5 700 7 5 000 20 75000 7 6 300 7 5 600 15 75600 7 6 900 7 6 200 10 76200 7 7 600 7 6 900 Means to Maximize Thrust Reduction and Margin OAT 15°C Takeoff Weight 70300 KG Peerrffoorrmaannccee Liimiitteedd bbyy Fiieelldd Leennggtthh The Boeing Company 737.38 Assumed temperature 38°C 38°C 38°C 40°C 40°C Field length required, ft Extra margin, ft 6507 6314 6360 6416 6461 493 686 640 584 539 Field Length Margin With Optimum Takeoff Configuration Takeoff configuration Flaps 5, A/C Auto Flaps 15, A/C Auto Flaps 5, A/C Off Flaps 15, A/C Auto Flaps 5, A/C Off The Boeing Company 737.39 7 3 7 -800W W ITH CFM5 6 -7B2 7 ENGINES PRESSUR E ALTITUDE 5000 FT RUNW AY L ENGTH 12000 FT , DRY NO O BSTACLES 27K, A /C AUTO OAT (C ) FLA P S 5 NO IMP C LB FLA P S 1 NO IMP C LB FLA P S 5 W ITH IMP CLB 60 57300 59300 60600 55 59900 62000 63200 50 62500 64700 65700 45 65100 67400 68300 40 68100 70500 71100 39 68700 71100 71600 37 69900 72400 72500 35 71000 73100 73400 30 73900 74000 75300 25 75400 74800 76500 20 76400 75500 77300 15 76400 76100 77700 10 76500 76800 78100 Means to Maximize Thrust Reduction and Margin OAT 10°C Takeoff Weight 71000 KG Peerrffoorrmaannccee Liimiitteedd bbyy Clliimbb oorr Obbssttaaccllee Clleeaarraannccee The Boeing Company 737.40 Performance Margins With Optimum Takeoff Option Assumed temperature 35°C 35°C 39°C 40°C Field length required, ft Extra margin, ft 9086 9804 10153 10642 2914 2196 1847 1358 Takeoff option Flaps 5, No Imp Climb Flaps 1, No Imp Climb Flaps 1, No Imp Climb Flaps 5, Improved Climb Climb gradient, % 2.54 2.93 2.58 2.58 The Boeing Company 737.41 The Takeoff Derate Method • Available for use on slippery or contaminated runways and with inoperative antiskid • Can be combined with use of assumed temperature The Boeing Company 737.42 737-800W WITH CFM56-7B27 ENGINES PRESSURE ALTITUDE 0 FT RUNWAY LENGTH 7000 FT, DRY NO OBSTACLES FLAPS 5, A/C AUTO, STANDARD TAKEOFF SPEEDS MAXIMUM RATED THRUST (27K) 24K DERATE OAT (C) MTOW (KG) PERF LIM V1 VR V2 (KT) MTOW (KG) PERF LIM V1 VR V2 (KT) 60 60400 FLD 134 135 140 55900 FLD 131 131 134 55 62200 FLD 136 137 142 57700 FLD 133 133 137 50 65000 FLD 138 139 146 59700 FLD 134 135 139 45 67200 FLD 140 141 148 61900 FLD 136 137 142 40 69300 FLD 141 143 150 64100 FLD 138 139 144 38 70300 FLD 142 144 151 65000 FLD 139 140 145 36 71100 FLD 142 145 152 65800 FLD 139 141 146 34 72000 FLD 143 145 153 66700 FLD 140 141 147 32 72900 FLD 143 146 154 67700 FLD 141 142 148 30 73700 FLD 144 147 155 68600 FLD 141 143 149 25 74300 FLD 144 147 156 69200 FLD 142 144 150 20 75000 FLD 145 148 156 69800 FLD 143 144 151 15 75600 FLD 146 149 157 70300 FLD 144 145 151 10 76200 FLD 146 149 157 71000 FLD 144 146 152 Runway Length Consideration OAT 15°C Takeoff Weight 70300 KG The Boeing Company 737.43 24K Derate OAT 15°C 27K assume 38°C 7000 22353 93.8 6507 24061 97.2 Parameter Field Length Required, ft Thrust per Engine at V1, lb Takeoff N1 Setting Using Derate Reduces Performance Margins The Boeing Company 737.44 737-800W WITH CFM56-7B27 ENGINES PRESSURE ALTITUDE 5000 FT RUNWAY LENGTH 12000 FT, DRY NO OBSTACLES FLAPS 5, A/C AUTO, STANDARD TAKEOFF SPEEDS MAXIMUM RATED THRUST (27K) 24K DERATE OAT (C) MTOW (KG) PERF LIM V1 VR V2 (KT) MTOW (KG) PERF LIM V1 VR V2 (KT) 60 57300 CLB 133 133 136 49300 CLB 124 124 126 55 59900 CLB 136 136 139 51500 CLB 126 126 129 50 62500 CLB 138 139 142 53800 CLB 129 129 132 45 65100 CLB 140 141 145 56200 CLB 132 132 134 40 68100 CLB 141 141 148 58900 CLB 135 135 138 35 71000 CLB 146 147 151 61700 CLB 138 138 141 30 73900 CLB 148 150 154 64600 CLB 140 141 144 25 75400 CLB 149 151 155 67600 CLB 143 144 147 20 76400 CLB 150 152 156 70800 CLB 146 147 151 15 76400 CLB 150 152 156 70900 CLB 146 147 151 10 76500 CLB 150 152 156 71000 CLB 146 147 151 Climb Consideration OAT 10°C Takeoff Weight 71000 KG The Boeing Company 737.45 24K Derate OAT 10°C 27K assume 35°C 2.4 2.54 Parameter One Engine Inoperative Climb Gradient (%) Using Derate Reduces Performance Margins The Boeing Company 737.46 737-800W WITH CFM56-7B27 ENGINES PRESSURE ALTITUDE 0 FT RUNWAY LENGTH 9000 FT, DRY OBSTACLE: 50 FT HT AT 1000 FT DIST FROM LIFTOFF END FLAPS 5, A/C AUTO, STANDARD TAKEOFF SPEEDS MAXIMUM RATED THRUST (27K) 24K DERATE OAT (C) MTOW (KG) PERF LIM V1 VR V2 (KT) MTOW (KG) PERF LIM V1 VR V2 (KT) 60 62900 OBS 138 138 143 57000 OBS 132 132 136 55 65200 OBS 140 141 145 59200 OBS 134 134 138 50 68600 OBS 142 144 149 61600 OBS 137 137 141 45 71300 OBS 144 146 152 64200 OBS 139 140 144 43 72400 OBS 145 147 153 65200 OBS 140 141 145 41 73500 OBS 146 148 154 66300 OBS 141 142 146 39 74600 OBS 147 149 155 67400 OBS 142 143 148 37 75700 OBS 147 150 156 68400 OBS 143 144 149 35 76700 OBS 148 151 157 69400 OBS 143 145 150 30 79300 OBS 149 153 160 72200 OBS 146 147 153 25 79800 OBS 150 153 160 72700 OBS 146 147 153 20 80300 OBS 150 154 161 73100 OBS 147 148 153 15 80800 OBS 151 154 161 73500 OBS 147 148 154 10 81300 OBS 151 155 161 73900 OBS 147 149 154 Obstacle Clearance Consideration OAT 15°C Takeoff Weight 73500 KG The Boeing Company 737.47 Using Derate Reduces Performance Margins 24K Derate OAT 15°C 27K assume 41°C 35 61 Parameter Net Clearance (ft) The Boeing Company 737.48 98 96 94 93 N1 OAT,, °C 27K and max allowable assumed temp 24K Derate at OAT 15 20 25 35 45 50 99 10 For Equivalent Performance, Using Derate Lowers N1 (RPM) and Achieves More Effective Thrust Reduction 30 40 97 95 The Boeing Company 737.49 Other Advantages Of Takeoff Derate • Permitted on slippery or contaminated runways, where the use of assumed temperature reduced thrust is prohibited • Permitted with anti-skid system inoperative • May increase maximum takeoff weight when performance is limited by VMCG • May improve aircraft loadability, for some models, by extending aft takeoff CG limit • Better trimmed for rotation and climbout for most models The Boeing Company 737.50 Summary On Performance Margins • Extra performance margins are inherent in the Assumed Temperature method of reduced thrust, including at the maximum allowable assumed temperature • Using those inherent margins for takeoff weight planning is prohibited! The Boeing Company 737.51

失速发表于 2010-6-11 00:27:31

回复 1# 民航的帖子

先顶后下！！！！！！！！

Virgin 发表于 2010-6-11 23:11:43

解决解决解决解决解决解决解决解决解决解决解决经济就

creek 发表于 2010-6-29 22:47:05

Reduced Thrust Considerations

howie666888 发表于 2010-7-3 15:07:13

gresareeeeeeeeeeeee

ida51737 发表于 2010-10-17 14:16:28

haohaohaoupupup

sdalwm 发表于 2011-3-10 20:13:58

Airbus A320 & A319 Study Guide 空客A320 & A319学习指南

wendellc 发表于 2011-3-11 13:47:45

下来看看学习学习

胖子发表于 2011-4-1 16:57:19

感谢楼主:handshake :handshake

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