Pearson Accountability Alliance

Exhibit A – Structure of Pearson’s Night Flight Budget

This Exhibit is an appendix to the main page, Pearson’s Night Flight “Restriction” Formula . It is written for residents, journalists, unions, health professionals, and public officials who need a clear, non-technical explanation of how the night budget works and why it matters.

The focus here is on structure: what the budget counts, what it does not count, how it grows over time, and how borrowing and carry-forward rules can apply upward pressure even when the airport claims there is “no increase” in night activity.

1. Core Idea: A Night Movement “Budget” That Grows with Demand

GTAA often presents the night program as a “restriction” based on a capped number of night movements each year. In practice, the quota is recalculated using a formula that:

• starts with a relatively high base allowance;
• adds a growth term tied to overall traffic;
• allows unused quota to be carried forward or borrowed; and
• excludes several categories of movements from the count.

The result is a system that allows night activity to increase alongside overall traffic, rather than a health-based limit that protects sleep. Residents can experience a dense pattern of night operations while the airport continues to state that it is “within the budget”.

2. Key Components of the Budget

The night budget can be understood as four main components. This table translates the technical rules into plain language and shows how each element affects real night operations.

Taken together, these elements mean that the night budget behaves like a demand-responsive envelope, not a fixed cap.

Component	Plain-language description	Effect on night operations
Base allowance	Starting number of permitted night movements each year, set at a level that already reflects a busy international hub.	Establishes a high baseline of night activity before any growth or carry-forward is added.
Growth component	Extra quota added when total traffic or passengers increase, often expressed as a small percentage or factor applied to daytime activity.	Allows the night budget to grow when the airport grows, even if communities are already exposed to harmful night noise.
Carry-forward / borrowing	Rules that allow unused quota in one year to be carried into another, or for future-years’ quota to be used early.	Creates a “buffer” of extra movements that can be deployed in busy years, supporting higher peaks in night activity.
Exempt / special categories	Movements that are partially or fully excluded from the budget count (for example, certain emergency, military, or late-running flights).	Reduces the official count relative to what residents actually experience, allowing more disturbances than the budget numbers suggest.

3. Exemptions: Movements That Do Not Count

The program materials identify several categories of night movements that do not count toward the formal budget. The exact list varies by document, but typically includes:

• Medical or emergency flights;
• Some diversions and weather-related re-routes;
• ATC-initiated safety or separation manoeuvres;
• Mechanical delay arrivals and departures;
• Some late-running daytime flights that slip into the night period; and
• International arrivals delayed by upstream congestion or crew constraints.

These exemptions are significant because:

• they can represent a large share of the night activity over communities; and
• they allow the airport to claim “compliance” with the budget while residents experience far more night flights than the official numbers imply.

4. Borrowing and Carry-Forward: Built-in Upward Pressure

The program allows the GTAA to borrow quota from future years and to carry forward unused quota from past years. On paper this is described as flexibility. In practice it can create a ratcheting effect:

• Borrowing from future years lets the airport treat tomorrow’s capacity as if it were available today, supporting high-demand years.
• Carrying forward unused quota allows unused budget from a slower year to be added on top of an already generous allowance in a busy year.

Net effect:

Borrowing and carry-forward embed structural upward pressure on the night budget. Capacity is rarely lost; instead, it can be redeployed to accommodate higher use later, even when communities are already experiencing harmful sleep disruption.

5. How This Differs from a True Cap or Curfew

A genuine night cap or curfew would typically:

• set a fixed maximum number of night movements (or none at all) that does not grow with demand;
• apply consistently to all non-emergency operations across the night period;
• prohibit borrowing from future years and limit or forbid carry-forward; and
• be grounded in independent health evidence and transparent community consultation.

Pearson’s night budget formula does almost the opposite:

• the effective ceiling grows with traffic rather than with health protections;
• multiple categories of flights are exempted or discounted; and
• borrowing and carry-forward allow peaks that would not be visible from the headline “budget” alone.

6. Plain-Language Pseudocode for the Budget

The following pseudocode is a plain-language representation of how the program behaves structurally. It is not an exact reproduction of any one internal document; it is intended to make the logic visible to non-specialists.

// For each year "Y" in the program
for each year Y:

    # 1. Start with the base allowance
    base_budget_Y = BASE_ALLOWANCE

    # 2. Add growth linked to demand
    growth_term_Y = growth_factor * daytime_movements_previous_year
    # (or passengers, or other demand metric)

    # 3. Add any carry-forward from earlier years
    carry_forward_Y = max(0, unused_budget_from_previous_years)

    # 4. Calculate the total allowed budget for year Y
    allowed_budget_Y = base_budget_Y + growth_term_Y + carry_forward_Y

    # 5. Count qualifying night movements
    night_count_Y = 0

    for each movement between 23:00 and 07:00 in year Y:

        if is_exempt(movement):
            # emergency, certain diversions, some late-running flights, etc.
            continue

        night_count_Y += 1

    # 6. Report status
    if night_count_Y > allowed_budget_Y:
        status_Y = "over budget"
    else:
        status_Y = "within budget"

This is a conceptual model only. The precise parameters and categories are defined in the program documentation obtained through ATIP/FOI and other disclosures.

7. Why This Exhibit Matters

This Exhibit is paired with the broader narrative on the Night Flight “Restriction” Formula page. Together, they show that:

• the night program is a flexible budget mechanism, not a strict cap or health-based curfew;
• the budget is designed to grow with demand rather than shrink toward safer levels of night noise;
• exempt categories remove many real flights from the count; and
• borrowing and carry-forward can hide the extent of night disturbance behind apparently compliant numbers.

In other words, the program most accurately operates as a demand-responsive authorization framework for night activity, not as a protective ceiling for residents’ health. Understanding the structure of the budget is essential for Boards of Health, unions, municipalities, and federal decision-makers tasked with evaluating whether Pearson’s operations are compatible with modern public-health standards.

← Back to: Pearson’s Night Flight “Restriction” Formula