# 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.

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</div>### 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**

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</div>### Descent Preparation

**PF:**

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

**PM:**

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

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</div>### Top of Descent (TOD)

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

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</div>### 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

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</div>#### 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

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</div>### Speed Management

- **Speed Mode → MANAGED (throughout STAR)**

The aircraft shall:

- Follow FMGS speed profile
- Respect all published constraints

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</div>### After STAR (Approach Phase Transition)

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

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</div>### Exceptions

Selected modes may be used if:

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

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</div>### Monitoring (PM)

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

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</div>### Energy Management

If aircraft is high or fast:

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

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</div>### Thrust Management

- Typically idle during descent
- Monitor engine parameters

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</div>### Transition Level

- Set local QNH when passing transition level

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</div>### Key Principles

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

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</div>### Core Rule

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

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</div>### Outcome

A properly managed descent results in:

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