9. Performance & Limits
- 9.1 Objective
- 9.2 Takeoff Performance
- 9.3 Approach & Landing Speeds
- 9.4 Flap Configuration & Limits
- 9.5 Taxi Speed Limits
- 9.6 Cruise Performance
- 9.7 Descent Performance & Energy Management
- 9.8 Operational Limits
- 9.9 Stabilized Approach as Performance Factor
- 9.10 Summary
9.1 Objective
This chapter provides a structured understanding of the Airbus A320 performance fundamentals and operational limits required for safe and efficient flight operations.
It is not intended to replace real-world performance manuals, but to give pilots the necessary knowledge to:
- Understand key speeds
- Operate within safe limits
- Maintain stable and predictable aircraft behavior
9.2 Takeoff Performance
V-Speeds Explained
Before every departure, three critical speeds must be calculated and inserted into the MCDU:
V1 – Decision Speed
- The maximum speed at which a rejected takeoff can be safely initiated
- After passing V1, the takeoff must be continued, even in case of failure
VR – Rotation Speed
- The speed at which the pilot initiates aircraft rotation
- Smooth and controlled pitch input is required
V2 – Takeoff Safety Speed
- Minimum safe climb speed after liftoff
- Ensures sufficient climb performance in case of engine failure
Operational Importance
Incorrect V-speeds can lead to:
- Unsafe takeoff performance
- Runway overruns
- Insufficient climb capability
Core Rule
“Takeoff performance is calculated – never estimated.”
9.3 Approach & Landing Speeds
VAPP – Final Approach Speed
VAPP is the target speed during final approach.
It includes:
- Reference landing speed (VLS)
- Wind correction
- Safety margin
Stability Requirement
Maintaining VAPP ensures:
- Stable descent
- Predictable aircraft response
- Safe landing performance
Operational Note
Excessive speed leads to:
- Long landing distance
- Unstable flare
Too low speed leads to:
- Reduced lift
- Increased stall risk
Core Rule
“A stable approach requires a stable speed.”
9.4 Flap Configuration & Limits
The Airbus A320 uses multiple flap configurations to adapt to different flight phases.
Flap Settings Overview
- Flaps 1 → Initial configuration
- Flaps 2 → Approach phase (GS intercept SOP)
- Flaps 3 → Intermediate landing config
- Flaps FULL → Final landing configuration
Speed Limits (Typical)
- Flaps 1 → max ~230 kt
- Flaps 2 → max ~200 kt
- Flaps 3 → max ~185 kt
- Flaps FULL → max ~177 kt
Operational Importance
Exceeding flap limits may cause:
- Structural damage
- System warnings
- Loss of control margin
Core Rule
“Configuration must always match speed.”
9.5 Taxi Speed Limits
Taxi speed is critical for:
- Safety
- Passenger comfort
- Ground operations
Standard Taxi Speeds
- Normal taxi → approx. 20 kt
- Outside apron → max 30 kt
Special Cases
- High-speed exit → 40 kt (max 50 kt)
- Tight turns → max 15 kt
Operational Importance
Excessive taxi speed increases:
- Brake wear
- Risk of runway/taxiway excursions
- Passenger discomfort
Core Rule
“Taxi speed must always match environment.”
9.6 Cruise Performance
Typical Cruise Envelope
- Altitude: FL320 – FL390
- Speed: Mach 0.76 – 0.80
Efficiency Considerations
- Higher altitude → lower fuel burn
- Managed speed → optimal performance
Monitoring Requirements
Pilots must monitor:
- Fuel consumption
- Wind conditions
- Flight progress
Core Rule
“Cruise is about efficiency, not speed.”
9.7 Descent Performance & Energy Management
Descent Characteristics
- Typically flown at idle thrust
- Vertical path controlled manually (VA SOP)
- Speed managed automatically
Energy State Awareness
Pilots must continuously assess:
- Altitude vs distance
- Speed vs configuration
High Energy Situation
- Too fast / too high
Correction methods:
- Increase descent rate
- Use speed brakes
Low Energy Situation
- Too slow / too low
Correction methods:
- Reduce descent rate
- Increase thrust
Core Rule
“Energy must be managed early – not corrected late.”
9.8 Operational Limits
Pilots must always respect:
- Speed limits (including flap limits)
- Aircraft configuration limits
- Stabilized approach criteria
- ATC restrictions
Importance
Limits are not recommendations – they define:
- Structural safety
- Aircraft performance
- Operational boundaries
Core Rule
“Limits are absolute – not optional.”
9.9 Stabilized Approach as Performance Factor
A stabilized approach is the final expression of correct performance management.
Requirements
- Correct speed (VAPP)
- Correct configuration
- Correct descent profile
Outcome
If performance is managed correctly:
- Aircraft arrives stable
- Landing becomes predictable
- Workload is reduced
Core Rule
“A good landing starts with good performance management.”
9.10 Summary
Performance management in the A320 is based on:
- Proper planning
- Correct speed usage
- Respecting aircraft limits
- Continuous monitoring
Final Principle
“Performance defines safety, efficiency and control.”