The theory subject "Flight performance and flight planning" deals with various aspects that can influence flight performance. These include weather, mass and centre of gravity as well as different flight phases. Flight planning is about how to adequately prepare for a flight.
Flight performance
This theory chapter describes in detail how various factors influence the performance of an aircraft, with a focus on weather-related variables. It emphasises that pilots usually rely on weather forecasts for flight planning, but these may differ from actual weather conditions. This requires a safety factor in planning. Particular emphasis is placed on the role of density, which decreases with increasing altitude and thus influences the performance of the engine and aerodynamic properties such as lift and propeller efficiency. Temperature also plays a role, as higher temperatures affect density and therefore flight performance in a similar way to higher altitude. Humidity also has an effect on density and therefore influences aerodynamic quality and engine performance.
In addition to these environmental factors, the importance of the load is emphasised. The correct distribution of mass on board is crucial for the aircraft's flight behaviour. Too much mass in the front or rear of the aircraft can disturb the balance and impair flight performance. Exceeding the maximum load is not permitted and must be authorised by the competent aviation authority.
The chapter also covers different phases of a flight (take-off, climb, cruise, descent and landing), using specific performance tables or diagrams in the flight manual for each phase. For each of these phases, the correct settings and planning are crucial to ensure both safety and efficiency. Finally, noise abatement measures that must be observed during flight operations to minimise noise pollution, especially in the vicinity of populated areas, are discussed.
Flight planning
A successful flight, especially a cross-country flight, requires thorough preparation that begins long before boarding the aircraft. The pilot must familiarise himself with all relevant information for a safe flight, whereby various aids are available, usually online. A central part of flight preparation is planning the flight route using up-to-date charts, from which important information such as fuel requirements, courses and estimated flight time is derived. This data is recorded in the flight execution plan and continuously updated during the flight.
Preparation includes gathering information on departure and destination airports, preparing and carrying flight documents such as weather reports, fuel and centre of gravity calculations, flight performance data, flight execution plans and necessary official documents. It is particularly important that the charts are up-to-date and fit for purpose, as air traffic is dynamic and requires accurate and up-to-date planning. This includes the consideration of country-specific differences in the chart display for international flights.
Flight briefings and weather information play a crucial role, as weather conditions have a significant influence on the feasibility of a flight. Various weather information, such as METARs, TAFs, GAFOR reports and AIRMETs, should be up-to-date and interpreted by meteorological experts if necessary.
The fuel calculation is another critical aspect that must be carried out precisely, as it influences both the flight duration and the aircraft mass. The total fuel requirement is made up of the consumption for climb, cruise and descent, the consumption for the alternate aerodrome and various reserves. In addition to the actual trip fuel, surcharges for the alternate aerodrome, starting and taxiing movements and reserve fuel must also be taken into account.
The flight plan is a central document that contains all the information and calculations required for navigation during the flight, such as heading, distances, times, important frequencies and fuel consumption. It is used to monitor and, if necessary, correct the planned flight path and is constantly updated by the pilot. Mass and centre of gravity calculations as well as take-off and landing distance calculations are also carried out here.