The COG range (Center of Gravity Range) of an aircraft defines the permissible range between the foremost and rearmost position of the center of gravity within which the aircraft can be operated safely. This range is defined by the manufacturer and certified by the aviation authorities. Compliance with the COG range is crucial for the safety and efficiency of flight operations.
Printout of the COG range:
Distance from a reference date:
The COG range can be expressed as a physical distance from a specified reference point, for example in inches or meters.
Percentage of the mean aerodynamic chord (MAC):
For fixed-wing aircraft, the COG range is often specified as a percentage of the mean aerodynamic chord (MAC). This enables a standardized specification that is independent of the size of the aircraft.
Example:
A typical COG range could be expressed as follows:
- COG range: 15 % to 35 % MAC
This means that the COG of the aircraft must be between 15 % and 35 % of the MAC under all loading conditions to ensure safe operation.
Significance of the COG area:
Stability, control and performance:
The COG range ensures that the aircraft remains stable and can be controlled well in all phases of flight. This is crucial for flight safety and the performance of the aircraft.
Protection against unsafe conditions:
A COG outside the permissible range can lead to unsafe flying conditions:
Forward center of gravity: If the COG is too far forward, the aircraft becomes nose-heavy. This can lead to difficulties when turning during take-off and to higher stall speeds.
Eighth focus: If the COG is too far back, the aircraft becomes tail heavy. This can lead to pitch instability and problems with recovery after a stall.
Dependencies of the COG area:
Aircraft type and configuration:
The COG range can vary depending on the aircraft type and configuration, e.g. between passenger and cargo aircraft.
Fuel location and consumption sequence:
The position of the fuel and the order in which it is consumed can influence the COG.
Payload distribution and loading processes:
The distribution of the payload and the way in which the aircraft is loaded are decisive for compliance with the COG range.
Use of the COG range:
Cargo planning and shipping:
The COG range is used when creating load plans and trim sheets to ensure that the aircraft is loaded within the permitted limits.
Flight testing and certification:
During flight testing and certification, the COG area is checked to ensure that the aircraft can be operated safely under various conditions.
Compliance with the COG range is therefore a key aspect of flight safety and efficiency.
English 
Deutsch