# Phase 6 — Fleet operations and utilization

Phase 6 derives operational fleet utilization without geographical or live aircraft tracking.

## Utilization

Daily snapshots calculate scheduled block minutes, actual block minutes, airborne minutes, cycles, revenue/non-revenue minutes, ground time, maintenance and operational downtime, and utilization percentage from completed flights. Monthly snapshots aggregate complete calendar months and calculate average daily utilization.

Revenue use includes scheduled passenger, charter, and cargo flights. Ferry, positioning, training, and maintenance-positioning flights are non-revenue use. Approved usage adjustments apply the recorded difference between previous and new values; pending or rejected records never affect calculations.

## Availability and downtime

Availability periods support Maintenance, Grounding, Lease, and Manual unavailability blocks in daily, weekly, and monthly views. Downtime records support Maintenance, Operational, Grounding, and Defect categories. All records require reasons and approval before affecting utilization. Phase 7 aircraft defects are also included in fleet-board defect counts while legacy approved Defect downtime records remain visible.

## Fleet board and reports

The fleet board shows master status and operational location, current/next/last flight records, calculated available-from time, airframe hours/cycles, upcoming approved maintenance blocks, and open defects. Reports cover utilization, availability, downtime, status history, block/airborne hours, cycles, and revenue versus non-revenue use.

## Security

Routes and services enforce `fleet-operations.view`, `manage`, `approve`, and `reports`. All queries are prepared and airline-scoped. Requests, approvals, rejections, and snapshot refreshes are audited. Approved records cannot be silently changed by a second approval decision.