General and airplane-wide limitations
Limitations define the edges of approved or recommended operation. This page first separates formal AFM material from other operating information, then collects the limits that apply to the aircraft as a whole.
What appears in this chapter
The source groups its material as AFM limitations, AFM operating information and non-AFM operating information. An item is included when it matters operationally or is demanded by an airworthiness directive or another regulatory rule. Material already built into a normal, supplementary or non-normal procedure is normally left there, and information printed on a placard, display or marking is normally not repeated.
Runway, wind, speed and altitude
| Area | Limit or action | Classification |
|---|---|---|
| Runway slope | Up to 2 percent uphill or downhill | AFM limitation |
| Takeoff and landing tailwind | 15 kt maximum Memory item | Capability was shown for takeoff and manual landing. Under the cited FAA rules, demonstration above 10 kt does not itself grant operating approval. |
| Maximum speeds | Comply with the gear and flap placards | AFM limitation |
| Operating altitude | 41,000 ft pressure altitude maximum | AFM limitation |
| Takeoff and landing altitude | 8,400 ft pressure altitude maximum | AFM limitation |
| Severe-turbulence penetration in climb or descent | 280 KIAS or Mach 0.76, whichever is lower Memory item | For cruise, use the severe-turbulence supplementary procedure. |
Latitude limits and installed ADIRU data
The permissible latitude depends on the magnetic-variation table installed in the ADIRU. The general boundary is 82 degrees north and south, but two longitude sectors impose a lower value: 70 degrees north between 80 degrees west and 130 degrees west, and 60 degrees south between 120 degrees east and 160 degrees east.
Departure and revenue-flight checks
When passengers are carried, verify before departure that the overwing-exit handle covers are fitted. During every flight day, perform one approved functional test of the flight-deck door entry system. On a revenue flight, the escape-slide retention bar, often called the girt bar, is installed for taxi, takeoff and landing.
RVSM altitude indications
The standby altimeters are not accurate enough to satisfy RVSM airspace requirements. In flight, the Captain and First Officer altitude displays may differ by no more than 200 ft during RVSM operation.
| Field elevation | Captain versus First Officer | Either primary display versus field elevation |
|---|---|---|
| Sea level through 5,000 ft | 50 ft | 75 ft |
| 5,001 through 10,000 ft | 60 ft | 75 ft |
Weight limitations
Certified weight limits are issued per tail number. Another AFM restriction may still reduce the usable value for a particular operation.
Which publication governs
The AFM certificate-limitations material can impose a lower weight than the headline figures shown here. Separate issue dates can also create a temporary disagreement between manuals. If that happens, the AFM value takes priority.
| Weight | Certified limit |
|---|---|
| Maximum taxi weight | 71,214 kg |
| Maximum takeoff weight | 70,987 kg |
| Maximum landing weight | 65,770 kg |
| Maximum zero fuel weight | 61,688 kg |
Air, automatic flight and communications
These limits protect the pressure vessel, prevent unsuitable automatic-flight use and define what the communication systems may be relied upon to do.
Air systems
If either engine bleed switch is ON, a pack must not be selected HIGH for takeoff, approach or landing. Fire-protection non-normal action has priority, so an operating pack is selected HIGH when the CARGO FIRE or SMOKE/FUMES REMOVAL checklist needs the added ventilation.
Autopilot and flight director
| Operation | Limitation |
|---|---|
| Aileron trim | Never apply it while the autopilot is engaged. Memory item |
| Autopilot engagement after takeoff | Do not engage below 400 ft AGL. Memory item |
| Single-channel approach under the cited FAA rules | Disengage by 50 ft AGL. Memory item |
| FAA-rule autoland winds | Headwind 25 kt, crosswind 20 kt, tailwind 15 kt. Memory item |
| Autoland glideslope | Between 2.5 and 3.25 degrees. Memory item |
| Autoland | Both engines operative, flaps 30 or 40. Memory item |
| LVL CHG on final | Do not use below 1,000 ft AFE. Memory item |
HF and communications
A flight must not be planned on HF frequencies 29.489 MHz or 29.490 MHz.
For primary ATC communication while on the ground, select the VHF installation connected to the upper fuselage antenna.
Engines and APU
Engine indications use colour to distinguish hard boundaries from caution regions. APU limits then depend on whether bleed air, electrical power or both are being supplied.
Engine operating limits
Red markings identify maximum and minimum engine limits; amber marks a caution range. Ignition is ON for takeoff, landing, heavy-rain operation and whenever anti-ice is operating. Assumed-temperature reduced takeoff thrust is not allowed when anti-skid is inoperative.
APU altitude envelope
| APU use | Maximum altitude | Applicability |
|---|---|---|
| Bleed plus electrical load in flight | 10,000 ft Memory item | Cited FAA rules |
| Bleed plus electrical load on the ground | 15,000 ft Memory item | Cited FAA rules |
| Bleed load only | 17,000 ft Memory item | All stated operations |
| Electrical load only | 41,000 ft Memory item | All stated operations |
Bleed valve and starting discipline
Close the APU bleed valve in any of these configurations: ground air connected with the isolation valve open; engine No. 1 bleed open; or both the isolation valve and engine No. 2 bleed open. It may stay open during engine start, but engine thrust should remain at or close to idle.
Three aborted starts in succession require 15 minutes of cooling. Before asking the APU to supply bleed air, let it run for a full 2 minutes.
Flight controls and navigation systems
The limits on this page protect structure and system validity. Several are easy to confuse because they use similar altitude figures for very different systems.
Flaps, speedbrakes and control inputs
| System or condition | Limit |
|---|---|
| Flaps extended | 20,000 ft maximum altitude. Memory item |
| Holding in icing | Do not hold with flaps extended. Memory item |
| Speed-brake lever in flight | Do not move it beyond the FLIGHT DETENT. |
| Speedbrakes below 1,000 ft radio altitude | Do not deploy in flight. Memory item |
| Rapid alternating inputs | Avoid large, fast reversals, especially combined pitch, roll and yaw or large sideslip, at every speed including below Va. Memory item |
Alternate-flap motor duty cycle
After releasing the ALTERNATE FLAPS position switch during extension or retraction, wait 15 seconds before moving it again. This protects the motor clutch. Once the flaps have travelled from zero through flap 15 and returned to zero, cool the system for 5 minutes before starting another extension.
ADIRU and magnetic-reference limits
Do not attempt ADIRU alignment beyond latitude 78 degrees 15 minutes. Magnetic-heading or magnetic-track operation is not permitted where the installed IRS magnetic-variation table error is more than 5 degrees. Use the approved IRS procedure to identify affected regions for the installed table.
GPWS and weather radar
The terrain display is not a navigation display. Do not use the look-ahead alert or terrain presentation during takeoff, approach or landing operations inside 15 NM of an airport or runway absent from the GPWS terrain database.
Fuel system and landing gear
Fuel limitations combine temperature, pump protection, lateral balance and loading sequence. The final landing-gear instruction is short but time critical.
Fuel temperature
Maximum tank temperature is 49 degrees Celsius. Before takeoff and while airborne, the minimum is the warmer of negative 43 degrees Celsius or 3 degrees Celsius above the actual freezing point of the fuel. Adding a fuel-system icing inhibitor does not lower that minimum.
Pumps, balance and loading
| Area | Required limit or action |
|---|---|
| Centre-tank pump | Do not deliberately run it dry while its low-pressure light is illuminated. |
| Planned lateral imbalance | Schedule the difference between main tanks 1 and 2 to zero. |
| Random lateral imbalance | 453 kg maximum during taxi, takeoff, flight and landing. |
| Centre-tank loading | If the centre tank holds more than 453 kg, main tanks 1 and 2 must both be full. |
Landing gear
Six-page memory map
| Page | Anchor figures | Main threat controlled |
|---|---|---|
| 1. General | 15 kt, 41,000 ft, 8,400 ft, 280 KIAS or Mach 0.76, 200 ft | Aircraft-wide boundary or indication error |
| 2. Weight | Four certified weights for each fleet group | Structural and certification limit |
| 3. Air, automatic flight, communications | 400 ft, 50 ft, 25, 20 and 15 kt | Unsuitable pack or automation configuration |
| 4. Engines and APU | 10,000, 15,000, 17,000 and 41,000 ft | Engine or APU misuse |
| 5. Controls and navigation | 20,000 ft, 1,000 ft, 78 degrees 15 minutes, 5 and 3 degrees | Structural load or invalid navigation reference |
| 6. Fuel and gear | 49 degrees, negative 43 degrees, 453 kg | Fuel-system damage, imbalance or premature braking |