High Altitude Maneuvering Catherine Davis
Flight Flight Operations Operations Engineering Engineering Boeing Boeing Commercial Commercial Airplanes A...
Flight Flight Operations Operations Engineering Engineering Boeing Boeing Commercial Commercial Airplanes Airplanes May May 2004 2004
737.1
High Altitude Maneuvers Discussion Topics
• Limits to Altitude Capability
• Maneuvering Issues – Impact of thrust limits on turn margins
• Recommendations/Considerations for Operation at High Altitude
The Boeing Company
737.2
Maximum Altitude There are three things that can limit Altitude Capability:
Maximum Certified Altitude (Structural Limit) Thrust-Limited Maximum Altitude Defined by Thrust / Drag relationship • User-defined Residual Rate of Climb (RROC) • Temperature-dependent!
Buffet-Limited Maximum Altitude Defined by Initial Buffet CL • User-defined maneuver margin The Boeing Company
737.3
Flight Management System (FMS) Control Display Unit (CDU) Airline Policy Page 1/2
The Boeing Company
737.4
737-400 Optimum and Maximum Altitude Optimum Altitude
39000
Buffet-limited Maximum Altitude (1.3g)
Max Cert Alt
37000
IS A +1 IS A IS + 1 0C A + 2 5C 0C
Altitude (ft)
35000
Thrust-limited Maximum Altitude (100 fpm)
33000
31000
29000
27000 30
40
50
60
70
Gross Weight (1000 kg)
70 The Boeing Company
80
90
100
11 0
120
130
140
150
(1000 lb)
737.5
737-800 Optimum and Maximum Altitudes Optimum Altitude
Thrust-limited Maximum Altitude (100 fpm)
43000
Max Cert Alt
41000
Altitude (ft)
39000
Buffet-limited Maximum Altitude (1.3g)
IS A +1 IS A + 1 0C 5C IS A +2 0C
37000
35000
33000
31000 40
50
60
70
80
Gross Weight (1000 kg)
90 The Boeing Company
100
110
120
13 0
140
150
160
170
(1000 lb)
737.6
737-800W Optimum and Maximum Altitudes Optimum Altitude 43000
Thrust-limited Maximum Altitude(100 fpm)
Max Cert Alt
41000
Buffet-limited Maximum Altitude(1.3g)
Altitude (ft)
39000
ISA IS A
37000
ISA +
+1
+1
0C
5C
20 C
35000
33000
31000 40
50
60
70
80
Gross Weight (1000 kg)
90 The Boeing Company
100
110
120
13 0
140
150
160
170
(1000 lb)
737.7
Primary Flight Display (PFD) Airspeed Indication The amber band: – displays the maneuver speed – provides 1.3g/40 degrees of bank angle (default) margin to buffet – constant regardless of ambient temperature NOTE: The amber band does not give any indication of thrust limits The Boeing Company
737.8
737-800 Drag vs Mach number Gross Weight = 70000 kg = 154323 lb Altitude = 35000 ft
13500 13000 12500 Drag (lb)
12000 11500 11000 10500 10000
Thrust Available
Margin to Thrust Limit in Level Flight
9500 9000
Drag in level flight
8500 0.6
0.65
Drag in Level Flight LRC
0.7
0.75
0.8
0.85
Mach number The Boeing Company
737.9
737-800 Drag vs Mach number Gross Weight = 70000 kg = 154323 lb Altitude = 35000 ft
13500 13000 12500 Drag (lb)
12000 11500
Drag in a 15º Turn
11000 10500 10000 9500
Thrust Available Drag associated with a 15º turn
Margin to Thrust Limit with 15º turn
9000
Drag in Level Flight LRC
8500 0.6
0.65
0.7
0.75
0.8
0.85
Mach number The Boeing Company
737.10
737-800 Drag vs Mach number Gross Weight = 70000 kg = 154323 lb Altitude = 35000 ft
13500 13000
Drag is higher than available thrust in 30º turn
12500 Drag (lb)
12000 11500 11000
Drag associated with a 30º turn
10500
Thrust Available
10000
Drag in a 30º Turn Drag in a 15º Turn Drag in Level Flight
9500 9000
LRC
8500 0.6
0.65
0.7
0.75
0.8
0.85
Mach number The Boeing Company
737.11
737-800 Drag vs Mach number Gross Weight = 70000 kg = 154323 lb Altitude = 35000 ft
13500 13000
More thrust is available in Max Continuous Thrust (MCT) mode
12500 Drag (lb)
12000
Drag in a 30º Turn
Thrust Available in CNT Mode
11500
Drag in a 15º Turn
11000 10500 10000
Thrust Available Drag in Level Flight
9500 9000
LRC
8500 0.6
0.65
0.7
0.75
0.8
0.85
Mach number The Boeing Company
737.12
737-400 Maneuver Capability at Maximum Altitude Standard Day 39000
Max Cert Alt
Altitude (ft)
37000
MCRT, 100 FPM
35000 LR
33000
C,
1. 3g
O pt im
In itia
um
M lB
CR
uf fe t(
M CR
T, 2
0º
40 ºB
31000
T, 1
Ba n
an
0º Ba nk k
k)
29000 40
The Boeing Company
70
45 80
50 90
55 60 65 Gross Weight (1000 kg) 100
110
120
70 130
75 140
80 150
(1000 lb) 737.13
737-800 Maneuver Capability at Maximum Altitude Standard Day 43000
Max Cert Alt
41000
MCRT, 10º Bank MCRT, 100 FPM 1.3
Altitude (ft)
39000
LR C 37000
,O pti
MC
RT
mu m
,2
gI ni t
0º
Ba
i al
Bu
nk
ffe t
(40 ºB
an
k)
35000
33000
31000 40
50
60
70
80
Gross Weight (1000 kg) 90 The Boeing Company
100
110
120
130
140
150
160
170
(1000 lb) 737.14
737-800 Maneuver Capability at Maximum Altitude ISA + 20ºC Day 43000
MCRT, 10º Bank
Max Cert Alt
41000
MCRT, 100 FPM MCRT, 20º Bank
Altitude (ft)
39000
LR C
37000
1.3
,O
pti
gI ni t
mu m
i al
Bu
ffe t
(40 ºB
an
k)
35000
33000
31000 40
50
60
70
80
Gross Weight (1000 kg) 90 The Boeing Company
100
110
120
130
140
150
160
170
(1000 lb) 737.15
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
737.16
Recommendations/Considerations for Flight at High Altitudes (cont) For LNAV deactivated:
Fly at least 10 knots above the lower amber band
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
Limit bank angles to no more than 10º for manual steering in cruise (set MCP bank angle selector to 10º from TOC to TOD)
