b737 high altitude-maneuvering

737.1

High Altitude ManeuveringHigh Altitude Maneuvering

Catherine DavisFlight Operations Engineering

Boeing Commercial AirplanesMay 2004

Catherine DavisFlight Operations Engineering

Boeing Commercial AirplanesMay 2004

737.2The Boeing Company

High Altitude ManeuversHigh Altitude Maneuvers

• Limits to Altitude Capability

• Maneuvering Issues – Impact of thrust limits on turn margins

• Recommendations/Considerations for Operation at High Altitude

• Limits to Altitude Capability

• Maneuvering Issues – Impact of thrust limits on turn margins

• Recommendations/Considerations for Operation at High Altitude

Discussion TopicsDiscussion Topics


Maximum AltitudeMaximum Altitude

Defined by Thrust / Drag relationship

• User-defined Residual Rate of Climb (RROC)

• Temperature-dependent!

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)


Flight Management System (FMS)Control Display Unit (CDU)

Flight Management System (FMS)Control Display Unit (CDU)

Airline Policy Page 1/2


27000

29000

31000

33000

35000

37000

39000

30 40 50 60 70

Gross Weight (1000 kg)

Alti

tude

(ft)

737-400 Optimum and Maximum Altitude737-400 Optimum and Maximum AltitudeBuffet-limited Maximum

Altitude (1.3g)

Thrust-limitedMaximum

Altitude (100 fpm)

ISA + 20C

ISA + 15C

ISA + 10C

OptimumAltitude

140(1000 lb)

8070 10090 110

120 130 150

Max Cert Alt


31000

33000

35000

37000

39000

41000

43000

40 50 60 70 80


Alti

tude

(ft)

737-800 Optimum and Maximum Altitudes737-800 Optimum and Maximum Altitudes

Max Cert AltBuffet-limited

MaximumAltitude (1.3g)


Altitude (100 fpm)

ISA + 20C

ISA + 15C

ISA + 10C

OptimumAltitude

160(1000 lb)

10090 120110 130

140 150 170


737-800W Optimum and Maximum Altitudes737-800W Optimum and Maximum Altitudes

31000

33000

35000

37000

39000

41000

43000

40 50 60 70 80


Alti

tude

(ft)

Buffet-limitedMaximum

Altitude(1.3g)


Altitude(100 fpm)

ISA + 20C

ISA + 15C

ISA + 10C

OptimumAltitude

160(1000 lb)

10090 120110 130

140 150 170

Max Cert Alt


Primary Flight Display (PFD) Airspeed Indication

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 amber band:– displays the

maneuver speed– provides 1.3g/40

degrees of bank angle (default) margin to buffet

– constant regardless of ambient temperature


850090009500

1000010500110001150012000125001300013500

0.6 0.65 0.7 0.75 0.8 0.85

Mach number

Dra

g (lb

)

737-800 Drag vs Mach number 737-800 Drag vs Mach number Gross Weight = 70000 kg = 154323 lbAltitude = 35000 ft

LRCDrag in level flight

Thrust Available

Drag in Level Flight

Margin to Thrust Limit in

Level Flight


850090009500

1000010500110001150012000125001300013500

0.6 0.65 0.7 0.75 0.8 0.85

Mach number

Dra

g (lb

)


LRC

Thrust Available

Drag associated with a 15º turn

Drag in a 15º Turn


Margin to Thrust Limit with 15º turn


850090009500

1000010500110001150012000125001300013500

0.6 0.65 0.7 0.75 0.8 0.85

Mach number

Dra

g (lb

)


LRC

Thrust Available

Drag associated with a 30º turn

Drag in a 30º Turn

Drag in a 15º Turn


Drag is higher than available thrust in

30º turn


850090009500

1000010500110001150012000125001300013500

0.6 0.65 0.7 0.75 0.8 0.85

Mach number

Dra

g (lb

)


LRC

Thrust Available

Drag in a 30º Turn

Drag in a 15º Turn


Thrust Available in CNT Mode

More thrust is available in Max Continuous Thrust (MCT) mode


29000

31000

33000

35000

37000

39000

40 45 50 55 60 65 70 75 80Gross Weight (1000 kg)

Alti

tude

(ft)

737-400 Maneuver Capability at Maximum Altitude

Standard Day

140(1000 lb)

8070 10090 110 120 130 150

LRC, Optimum

1.3g Initial Buffet (40º Bank)

MCRT, 20º Bank

MCRT, 10º Bank

MCRT, 100 FPM

Max Cert Alt




31000

33000

35000

37000

39000

41000

43000

40 50 60 70 80Gross Weight (1000 kg)

Alti

tude

(ft)

Standard Day

LRC, Optimum

MCRT, 20º Bank


MCRT, 100 FPMMCRT, 10º Bank

160(1000 lb)

10090 120110 130 140 150 170

Max Cert Alt




31000

33000

35000

37000

39000

41000

43000

40 50 60 70 80Gross Weight (1000 kg)

Alti

tude

(ft)

ISA + 20ºC Day

LRC, Optimum


MCRT, 100 FPM

MCRT, 10º Bank

160(1000 lb)

10090 120110 130 140 150 170

Max Cert Alt

MCRT, 20º Bank


Recommendations/Considerationsfor Flight at High Altitudes

Recommendations/Considerationsfor Flight at High Altitudes

To get accurate altitude limits from the FMC:Enter an accurate aircraft weightEnter an accurate temperature deviation at the cruising altitude

To get accurate altitude limits from the FMC:Enter an accurate aircraft weightEnter 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.

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.


Recommendations/Considerationsfor Flight at High Altitudes (cont)

Recommendations/Considerationsfor 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

required3. Descend

b737 high altitude-maneuvering

Education