737.1 High Altitude Maneuvering Catherine Davis Flight Operations Engineering Boeing Commercial Airplanes May 2004 The Boeing Company 737.2 High Altitude Maneuvers • Limits to Altitude Capability • Maneuvering Issues – Impact of thrust limits on turn margins • Recommendations/Considerations for Operation at High Altitude Diissccuussssiioonn Tooppiiccss The Boeing Company 737.3 Maximum Altitude Defined by Thrust / Drag relationship • User-defined Residual Rate of Climb (RROC) • Temperature-dependent! Thrust-Limited Maximum Altitude There are three things that can limit Altitude Capability: Defined by Initial Buffet CL • User-defined maneuver margin Buffet-Limited Maximum Altitude Maximum Certified Altitude (Structural Limit) The Boeing Company 737.4 Flight Management System (FMS) Control Display Unit (CDU) Airline Policy Page 1/2 The Boeing Company 737.5 27000 29000 31000 33000 35000 37000 39000 30 40 50 60 70 Gross Weight (1000 kg) Altitude (ft) 737-400 Optimum and Maximum Altitude Buffet-limited Maximum Altitude (1.3g) Thrust-limited Maximum Altitude (100 fpm) ISA + 20C ISA + 15C ISA + 10C Optimum Altitude 140 (1000 lb) 70 80 90 100 11 0 120 130 150 Max Cert Alt The Boeing Company 737.6 31000 33000 35000 37000 39000 41000 43000 40 50 60 70 80 Gross Weight (1000 kg) Altitude (ft) 737-800 Optimum and Maximum Altitudes Max Cert Alt Buffet-limited Maximum Altitude (1.3g) Thrust-limited Maximum Altitude (100 fpm) ISA + 20C ISA + 15C ISA + 10C Optimum Altitude 160 (1000 lb) 90 100 110 120 13 0 140 150 170 The Boeing Company 737.7 737-800W Optimum and Maximum Altitudes 31000 33000 35000 37000 39000 41000 43000 40 50 60 70 80 Gross Weight (1000 kg) Altitude (ft) Buffet-limited Maximum Altitude(1.3g) Thrust-limited Maximum Altitude(100 fpm) ISA + 20C ISA + 15C ISA + 10C Optimum Altitude 160 (1000 lb) 90 100 110 120 13 0 140 150 170 Max Cert Alt The Boeing Company 737.8 Primary Flight Display (PFD) Airspeed Indication NOTE: The amber band does not give any indication of thrust limits The amber band: – displays the maneuver speed – provides 1.3g/40 degrees of bank angle (default) margin to buffet – constant regardless of ambient temperature The Boeing Company 737.9 8500 9000 9500 10000 10500 11000 11500 12000 12500 13000 13500 0.6 0.65 0.7 0.75 0.8 0.85 Mach number Drag (lb) 737-800 Drag vs Mach number Gross Weight = 70000 kg = 154323 lb Altitude = 35000 ft Drag in level flight LRC Thrust Available Drag in Level Flight Margin to Thrust Limit in Level Flight The Boeing Company 737.10 8500 9000 9500 10000 10500 11000 11500 12000 12500 13000 13500 0.6 0.65 0.7 0.75 0.8 0.85 Mach number Drag (lb) 737-800 Drag vs Mach number Gross Weight = 70000 kg = 154323 lb Altitude = 35000 ft LRC Thrust Available Drag associated with a 15º turn Drag in a 15º Turn Drag in Level Flight Margin to Thrust Limit with 15º turn The Boeing Company 737.11 8500 9000 9500 10000 10500 11000 11500 12000 12500 13000 13500 0.6 0.65 0.7 0.75 0.8 0.85 Mach number Drag (lb) 737-800 Drag vs Mach number Gross Weight = 70000 kg = 154323 lb Altitude = 35000 ft LRC Thrust Available Drag associated with a 30º turn Drag in a 30º Turn Drag in a 15º Turn Drag in Level Flight Drag is higher than available thrust in 30º turn The Boeing Company 737.12 8500 9000 9500 10000 10500 11000 11500 12000 12500 13000 13500 0.6 0.65 0.7 0.75 0.8 0.85 Mach number Drag (lb) 737-800 Drag vs Mach number Gross Weight = 70000 kg = 154323 lb Altitude = 35000 ft LRC Thrust Available Drag in a 30º Turn Drag in a 15º Turn Drag in Level Flight Thrust Available in CNT Mode More thrust is available in Max Continuous Thrust (MCT) mode The Boeing Company 737.13 29000 31000 33000 35000 37000 39000 40 45 50 55 60 65 70 75 80 Gross Weight (1000 kg) Altitude (ft) 737-400 Maneuver Capability at Maximum Altitude Standard Day 140 (1000 lb) 70 80 90 100 110 120 130 150 LRC, Optimum 1.3g Initial Buffet (40º Bank) MCRT, 20º Bank MCRT, 10º Bank MCRT, 100 FPM Max Cert Alt The Boeing Company 737.14 737-800 Maneuver Capability at Maximum Altitude 31000 33000 35000 37000 39000 41000 43000 40 50 60 70 80 Gross Weight (1000 kg) Altitude (ft) Standard Day LRC, Optimum MCRT, 20º Bank 1.3g Initial Buffet (40º Bank) MCRT, 100 FPM MCRT, 10º Bank 160 (1000 lb) 90 100 110 120 130 140 150 170 Max Cert Alt The Boeing Company 737.15 737-800 Maneuver Capability at Maximum Altitude 31000 33000 35000 37000 39000 41000 43000 40 50 60 70 80 Gross Weight (1000 kg) Altitude (ft) ISA + 20ºC Day LRC, Optimum 1.3g Initial Buffet (40º Bank) MCRT, 100 FPM MCRT, 10º Bank 160 (1000 lb) 90 100 110 120 130 140 150 170 Max Cert Alt MCRT, 20º Bank The Boeing Company 737.16 Recommendations/Considerations for Flight at High Altitudes To get accurate altitude limits from the FMC: Enter an accurate aircraft weight Enter an accurate temperature deviation at the cruising altitude For LNAV operation: the FMC provides a real-time bank angle limiting function this function will protect the commanded bank angle from exceeding the current available thrust limit. this bank angle protection is not available when LNAV mode is deactivated. The Boeing Company 737.17 Recommendations/Considerations for Flight at High Altitudes (cont) For LNAV deactivated: Fly at least 10 knots above the lower amber band Limit bank angles to no more than 10º for manual steering in cruise (set MCP bank angle selector to 10º from TOC to TOD) If speed drops below the lower amber band limit, immediately increase speed by doing one or more of the following: 1. Reduce bank angle (to 10 - 15º maximum) 2. Increase thrust (up to maximum continuous thrust) as required 3. Descend