4.7 Descent

Objective

To conduct a controlled and passenger-comfort-oriented descent from cruise altitude to approach phase while maintaining compliance with all constraints.

Descent Philosophy (VA Standard)

The descent is primarily flown with a focus on:

• Passenger comfort (smooth vertical profile)
• Pilot control over vertical path
• Compliance with ATC and charted constraints

Descent Preparation

PF:

• Reviews arrival (STAR, constraints, transition)
• Conducts approach briefing

PM:

• Programs arrival and approach into MCDU
• Verifies constraints and routing

Top of Descent (TOD)

• Descent initiated prior to or at TOD
• ATC clearance must be received before descent

Descent Mode (STANDARD VA PROCEDURE)

Vertical Mode:

• Primary Mode → SELECTED V/S (Vertical Speed)

The descent is manually controlled to ensure:

• Smooth cabin experience
• Stable and predictable vertical profile

Managed Mode Usage:

• Managed Descent is NOT the default
• It is used only when required to comply with constraints

Examples:

• Altitude restrictions on STAR
• Complex vertical profiles
• When automation assistance is beneficial

Speed Management

• Speed Mode → MANAGED (throughout STAR)

The aircraft shall:

• Follow FMGS speed profile
• Respect all published constraints

After STAR (Approach Phase Transition)

• Speed may be adjusted as required:
  • ATC instructions
  • Approach setup
  • Traffic situation

Exceptions

Selected modes may be used if:

• ATC assigns specific:
  • Speed
  • Descent rate
  • Altitude constraints
• Abnormal situations occur

Monitoring (PM)

• Vertical path vs constraints
• Speed profile
• ATC compliance
• Energy state (too high / too fast)

Energy Management

If aircraft is high or fast:

• Increase descent rate (V/S adjustment)
• Use Speed Brakes as required

Thrust Management

• Typically idle during descent
• Monitor engine parameters

Transition Level

• Set local QNH when passing transition level

Key Principles

• Smooth descent is priority
• Maintain control over vertical profile
• Use automation selectively, not blindly

Core Rule

“Vertical path is pilot-controlled – speed is aircraft-managed.”

Outcome

A properly managed descent results in:

• Passenger comfort
• Stabilized approach conditions
• Reduced workload in final phase