Flight Planning and Navigation Documentation
Core Concepts
Flight planning for a CPL is a documentation discipline as much as a calculation exercise. You must know the fuel plan components: taxi fuel, trip fuel, contingency (typically a percentage of trip fuel), alternate fuel, final reserve, and any additional fuel. Be able to state the minimum fuel on board at take-off and explain what happens when the destination forecast deteriorates below the planning minima.
Know the operational flight plan, the navigation log, the load sheet and the technical log, and what each legally records. Understand the role of the AIP, NOTAMs, METAR/TAF/TAFOR trends, and how to extract runway, elevation, declared distance and obstacle data. For performance, the key inputs are pressure altitude, temperature, wind, runway slope and surface, and mass; the trap is using indicated rather than pressure altitude.
Be comfortable converting: pressure altitude = elevation + (1013 − QNH) × 30 ft approximately. Density altitude rises with temperature and with low pressure, degrading both take-off and climb performance. For alternate planning, know the weather minima required and the fuel to reach the alternate, approach and land.
Traps in Questions
- Omitting the final reserve when stating minimum take-off fuel.
- Using QNH elevation figures when the question supplies QFE or pressure altitude.
- Confusing maximum take-off mass with maximum landing mass when a fuel jettison or en-route burn is possible.
- Forgetting that a TAF validity period and a TEMPO or BECMG group mean different things.
Worked Example
Trip fuel 180 kg, taxi 10 kg, contingency 5% of trip (9 kg), alternate 40 kg, final reserve 45 kg. Minimum take-off fuel = 10 + 180 + 9 + 40 + 45 = 284 kg. If the destination forecast is marginal, add holding fuel and re-check the alternate minima before dispatch.