What is O/R in Aviation? (On Request)

Aviation is a complex industry that operates on precise schedules and meticulous planning. In order to keep flights running smoothly and efficiently, there are various terms and procedures that play a crucial role in the aviation system. One such term is “On Request” (O/R), which is an important concept in aviation communication and coordination. In this article, we will explore the significance of On Request and how it is utilized in different aspects of aviation.

The Meaning of On Request (O/R)

On Request (O/R) is an abbreviation commonly used in aviation to indicate a specific action or service that is not automatically provided but can be requested by the relevant parties. It is a way to manage and streamline communication and coordination within the aviation industry. Whenever an action or service is designated as On Request, it means that it will only be carried out when explicitly requested by the appropriate personnel.

On Request is used in various aviation contexts, ranging from flight operations to air traffic control. It ensures that certain tasks or activities are not performed automatically or without proper authorization, but rather on-demand and as required. By utilizing the On Request system, aviation professionals can effectively manage their resources and prioritize tasks based on specific needs.

On Request in Flight Operations

In the realm of flight operations, On Request is often used to refer to services or accommodations for passengers or crew members. For instance, in-flight meals or special dietary requests can be indicated as On Request, indicating that they will only be provided if specifically requested in advance. Similarly, extra legroom seats, seat upgrades, or other amenities may also be offered on an On Request basis to ensure efficient allocation of resources.

When it comes to aircraft maintenance, On Request is deployed to manage repairs and maintenance services. Maintenance tasks that are not considered critical or immediate can be designated as On Request, allowing airlines to schedule them according to the availability of resources and the overall operational needs. This helps in optimizing maintenance operations and minimizing disruptions to flight schedules.

Furthermore, On Request plays a significant role in fuel services. Airlines or operators may request fuel services On Request to avoid wastage and ensure that fuel is supplied as per their specific requirements. This allows for better planning and utilization of fuel resources, contributing to cost management and overall operational efficiency.

On Request in Air Traffic Control

In air traffic control, On Request has a crucial role in managing air traffic flow and facilitating safe and efficient operations. When an aircraft requests permission to deviate from its assigned flight path or alter its altitude, the request is made On Request to the air traffic control. This ensures that any changes in the aircraft’s trajectory or altitude are carefully considered and coordinated to avoid conflicts with other aircraft or airspace restrictions.

During flight planning and coordination, On Request may also be used to request clearance for certain airspace segments or routes. Airlines or pilots can submit requests for specific routes or airspace utilization, which are then reviewed and approved on an On Request basis by air traffic control authorities. This helps in optimizing airspace utilization and accommodating the specific requirements of different flights.

Additionally, On Request is significant when it comes to aircraft ground handling services. Ground handling includes various operations performed on an aircraft while it is on the ground, such as refueling, defueling, catering, baggage handling, and more. These services are requested by the airline or operator On Request to ensure smooth coordination of resources and timely execution of the required tasks.


On Request (O/R) is a critical concept in aviation, playing a pivotal role in ensuring effective communication, resource management, and coordination. From flight operations to air traffic control, On Request allows for the efficient allocation of resources, prioritization of tasks, and optimization of operational procedures. By understanding the meaning and application of On Request, aviation professionals can streamline their processes and deliver safe and efficient services to passengers and crew members.

For more information about aviation terminology and concepts, you can refer to Skybrary, a comprehensive online resource for aviation professionals.

For More: What is LOTC in Aviation? (Loss Of Thrust Control)