Limitations - Boeing

Boeing The Boeing philosophy governing the content of the Operations Manual Limitations Section is a function of EICAS messages and cockpit placards. Any item that generates an EICAS message or is a limitation that is covered by a cockpit placard is not listed in the limitations section. The Operations Manual Limitations Section content, in general, is restricted to those items the crew must commit to memory in order to safely and efficiently operate the airplane.

Operational Limitations

	• Runway Slope	±2%
	• Maximum Operating Altitude	42,000 ft pressure altitude
	• Maximum Take-Off and Landing Altitude	8,400 ft pressure altitude HI ALT OPS 9,500 / 13,500 ft pressure altitude
	• Maximum Take-Off and Landing Tailwind Component	15 kts 10 kts

Miscellaneous Limitations

Emergency Lighting

Photo luminescent Floor Emergency Lighting must be charged in accordance with approved procedures.

ACARS

Air Conditioning

When the airplane is electrically powered for more than 20 minutes on the ground, equipment cooling must be provided as shown below:

Temperature (OAT)	COOLING REQUIRED
34° C to 40° C (94° F to 105° F)	One forward and one aft entry door on opposite sides open, or at least one Air Conditioning pack or equivalent ground cooling operating.
41° C to 49° C (106° F to 120° F)	At least one Air Conditioning pack or equivalent ground cooling operating.
More than 49° C (120° F)	Two Air Conditioning packs or equivalent ground cooling operating.

APU

• Do not start or shutdown APU whilst refuelling. Note: Non-AFM Operational Information.

Auto Flight

• CAA After Take-Off, the autopilot must not be engaged below 500 ft.
• FAA After Take-Off, the autopilot must not be engaged below 200 ft.
• Use of Aileron trim with the autopilot engaged is prohibited.
• HI ALT OPS Do not use the autopilot below 100 ft. Radio Altitude at airport pressure altitudes above 8400 ft.
• Maximum allowable wind speeds when landing weather minima are predicated on autoland operations:

Headwind	25 kts
Crosswind	25 kts
Tailwind	15 kts 10 kts

• On a single channel ILS approach, disengage the autopilot at not less than 180 feet ARTE. (above runway threshold elevation).
• On an approach using VS mode the autopilot must be disengaged at or above 300 feet ARTE.

Autoflight - General Limitations

• The autopilot must be disengaged in severe turbulence unless CWS is installed and selected.
• The flight director has not been assessed in any abnormal configuration except that used in a single engine approach. It may be used in this configuration but must be closely monitored.

Automatic Landing

• All engines must be operating to initiate an automatic landing.
• One engine may be inoperative to initiate an automatic landing.

• The maximum and minimum glide slope angles for automatic landing are 3.1° and 2.5° respectively.
• Automatic landings may be made with Flaps 25 or 30 only.
• All three Hydraulic systems must be operating.
• Two Electrical systems must be operating (The APU generator may be used to power one system).
• The Inertial Reference Systems associated with the engaged autopilots must be in NAV mode.
• At least two autopilots must be engaged and the autoland status annunciators must show LAND 2 or LAND 3 at and below 600 feet.

DH Below 200 Feet but not less than 100 feet

• The Automatic Landing limitations must be observed whether the landing is to be completed manually or automatically.
• The autopilot must be coupled to an ILS which conforms to the requirements of ECAC Document 17 for Category II operations.
• The decision height must be identified by reference to Radio Altitude and must not be less than OCA/H (obstacle clearance altitude / height). Where an OCA/H is not promulgated, the decision height may be determined by an alternative method acceptable to the CAA.

DH Below 100 Feet but not less than 50 feet

• The Automatic Landing limitations must be observed.
• The autopilot must be coupled to an ILS which conforms to the requirements of ECAC Document 17 for automatic landing with a decision height down to 50 feet.
• The decision height must be identified by reference to Radio Altitude.

DH 50 Feet or Less

• The first four Automatic Landing limitations must be observed.
• All three autopilots must be engaged and the autoland status annunciators must show LAND 3 at and below 600 feet.
• The autopilot must be coupled to an ILS which conforms to the requirements of ECAC Document 17 Category III operations.

Autothrottle

• The autothrottle must not be used in a single engine approach.

Bird Strike Protection

• To provide bird strike protection, do not exceed 313 KIAS below 8,000 ft.

Communications

• Do not operate the HF radios during refueling operations. Note: Non-AFM Operational Information.

Crosswind Limitation

• Maximum demonstrated takeoff and landing crosswind is 30 kts (not limiting). Note: Non-AFM Operational Information.

Door Mounted Escape Slides

• Entry Door evacuation slide systems must be armed and engagement of the girt bar with door sill verified prior to taxi, takeoff, or landing whenever passengers are carried.

Engine Fuel System

• The maximum Fuel temperature is 49° C. Note: JP4/Jet B: 29° C.
• The minimum fuel temperature is minus 45° C or 3° C above the freeze point, whichever is higher.
• The center tank may contain up to 907 kg (2000 lb) of fuel with less than full left or right main tanks provided center tank fuel weight plus actual zero fuel weight does not exceed the Maximum Zero Fuel Weight, and center of gravity limits are observed.

• Lateral fuel imbalance must not exceed 880 kilograms for all operations.

Engine Ignition

• Continuous Ignition must be on (engine start selector in the CONT position) while operating in severe turbulence.

  Note: Continuous ignition is automatically provided in icing conditions when Engine Anti-Ice is on.

Time Limits for TO/GA Thrust for Take-Off

The time limits on the use of TO/GA thrust following loss of thrust on one engine or engine failure are as follows:

• 5 minutes
• 10 minutes

Engine Vibration

• Flight crew shall not blank engine vibration display during takeoff.

Fire Protection

• The Cabin Pressurization system must be operable at takeoff whenever cargo is carried in the lower Cargo Compartment.

Flight Controls

• The maximum altitude for Flap extension is 20,000 ft.

  explanation

  
  

  • At low velocities air can be considered an essentially incompressible fluid. However, when an aircraft increases speed and/or climbs to a sufficiently high altitude, the surrounding air increasingly assumes the characteristics of a compressible fluid.
  • It is necessary to either account for these (compressibility) characteristics in the aircraft design or impose limitations to prevent operation in the region of the operating envelope where compressibility effects exist. The Mach number at which compressibility becomes significant ranges from approximately 0.50 to 0.55M.
  • For Flaps up, high-speed flight, the compressibility effects are accounted for in design of the aircraft structure as well as for handling qualities, performance, etc. However, the high lift systems are normally intended for use during relatively low speed flight and consequently are designed using low speed, incompressible aerodynamic data.
  • The flap placard speeds (in knots IAS) are established in relation to the altitude where compressibility effects (Mach Number) could be expected to significantly influence the aerodynamic characteristics of the airplane. In standard atmospheric conditions, flap placard speed approaches the compressibility significant Mach number range at approximately 20000 ft.
  • The operation of high lift devices is limited to altitudes no greater than 20,000 ft. Operation of high lift devices at altitudes greater than 20,000 ft may place the aircraft into a flight regime for which it was not specifically designed and may produce unexpected aerodynamic characteristics.
• Avoid rapid and large alternating control inputs, especially in combination with large changes in pitch, roll, or yaw (e.g. large side slip angles) as they may result in structural failure at any speed, including below VA.
• Speedbrakes: Do not extend in flight when wing flaps are at position 25 or 30.
• Speedbrakes: Do not extend in flight below 800 ft AGL.

Icing Conditions

• The Wing Anti-Ice system should be turned on at the first indication of icing as indicated by ice accumulation on the flight deck front window frames, windshield center post, windshield wiper post, or side windows. The wing anti-ice system should remain on until the airplane has exited icing conditions.

ILS Approaches

The airplane is approved only for the following kinds of ILS approach and landing:

Decision height 200 feet or more:

• Manual approach with or without flight director.
• Single, dual, or triple channel automatic approach and manual landing.
• Dual or triple channel automatic approach and landing.

Decision height below 200 feet but not less than 100 feet:

• Dual or triple channel automatic approach and manual landing.
• Dual or triple channel automatic approach and landing.

Decision height below 100 feet but not less than 50 feet:

• Dual or triple channel automatic approach and landing.

Decision height 50 feet or less:

• Triple channel automatic approach and landing.

No decision height:

• Triple channel automatic approach and landing.

Flight Instruments

Electronic Flight Bag (EFB)

Navigation

• Do not operate under IFR or at night into airports north of 73° North or south of 60° South latitude whose navigation aids are referenced to magnetic north.

• The navigation and display system does not support operations at latitudes greater than 87° North or South. Note: Non-AFM Operational Information.

• For airplanes with the Air Traffic Services options activated, ATC clearance data received through the FMC, which can only be viewed on the cockpit printer, must be independently verified with the originating ground stations.

Precipitation on the Runway

The maximum precipitation depth allowable on the runway for Takeoff:

• Dry Snow - 6 cm
• Standing water, wet snow, or slush - 13 mm

Reduced Vertical Separation Minimum (RVSM) Altimeter Cross Check Limits

• Standby altimeters do not meet altimeter accuracy requirements of RVSM.

Field Elevation	IAS/ Mach	Max Difference Between Captain's and First Officer's Altimeters	Max Difference Between Captain's or First Officer's Altimeters and Field Elevation
Sea Level	0	40 ft	75 ft
5,000 feet	0	45 ft	75 ft
10,000 feet	0	50 ft	75 ft

Max Difference between Captain's and First Officer's Altimeters - Inflight	200 ft

Reverse Thrust

• Reverse Thrust is for ground use only.

Turbulent Air Penetration Speed

• 290 kias / .78 Mach. Note: Non-AFM Operational Information.

Warning Systems

Ground Proximity Warning System (GPWS) Look-Ahead Alerting

Weather Radar

• Do not operate the weather radar in a hanger or within 50 feet of any personnel or fuel spill.

  Note: The hanger and personnel restrictions do not apply to the weather radar test mode.

Weight Restrictions

Note : The following tables are given as examples only. Please refer to FCOM Limitations for current restrictions.

Limitations	757-200 (Light)	757-200 (Heavy)	757-300
Maximum Taxi Weight (MTW)	100,243 kg (221,000 lbs)	116,119 kg (256,000 lbs)	118,387 kg (261,000 lbs)
Maximum Take Off Weight (MTOW)	99,790 kg (220,000 lbs)	115,893 kg (255,500 lbs)	117,934 kg (260,000 lbs)
Maximum Landing Weight (MLW)	89,811 kg (198,000 lbs)	95,253 kg (210,000 lbs)	101,604 kg (224,000 lbs)
Maximum Zero Fuel Weight (MZFW)	83,460 kg (184,000 lbs)	85,000 kg (187,400 lbs)	95,254 kg (210,000 lbs)

Other Weight Restrictions

Note: These weights may be further restricted by Company registered limits, field length limits, climb limits, tire speed limits, brake energy limits, obstacle clearance, or enroute and landing requirements.

Company Limitations

Minimum Flight Crew Oxygen Quantity

Prior to despatch from a main base the minimum Oxygen pressure shall be 1300 psi.

Engine Oil Quantity

Prior to despatch the minimum indicated Engine Oil Quantity shall be 16 US quarts.

Engine, IDG and APU Oil Specification

Mobil Jet II

Hydraulic Oil Specification

Skydrol 500 B4

Approved Fuel Specifications

Fuel Type	Specification	Comments	Freezing Point	Flash Point
Kerosene (AVTUR)	Jet A Jet A1 [NATO F35] JP-8 Grade [NATO 34] British DERD 2453 British DERD 2494 Canadian CAN 2-3.23	ASTM D1655-75 ASTM D1655-75 MIL-T-83133	-40 -47 -47 -47 -47 -47	+38 +38 +38 +38 +38 +38
Wide Cut Fuel (AVTAG) [used in cold climates]	Jet-B JP-4 Grade [NATO F40] British DERD 2454 British DERD 2486 Canadian CAN 2-3.22	ASTM D1655-75 MIL-T-5624K	-50 -58 -58 -50 -50	-18 -18 -18 -18 -18
High Flash Point Fuel (AVCAT)	JP-5 Grade [NATO F44] British DERD 2498	MIL-T-5624K	-46	+60

Aircraft Category

For the purposes of instrument approach procedures and landing minima, B757-200 aircraft are Category 'C'.

For the purposes of instrument approach procedures and landing minima, B757-300 aircraft are Category 'D'.