What is EDTO in Aviation? (Extended Diversion Time Operations)

In the complex world of aviation, there are various terms and procedures that ensure the safety and efficiency of flights. One such term is Extended Diversion Time Operations, commonly referred to as EDTO. EDTO is a set of rules and guidelines established by aviation authorities to regulate the length of time an aircraft can operate away from a suitable airport in the event of an engine failure. It is an essential concept that ensures the safety of passengers and crew by minimizing the risks associated with long-distance flights.

EDTO is particularly applicable to twin-engine aircraft, as these aircraft rely solely on their engines for propulsion. In the event of an engine failure, a twin-engine aircraft needs to divert to a suitable airport for an emergency landing. However, in certain long-distance routes, there may not be a suitable airport within a reasonable distance. EDTO regulations ensure that twin-engine aircraft can still operate safely on these routes.

Now, let’s delve deeper into the world of Extended Diversion Time Operations and understand how it affects aviation.

Ensuring Safety through EDTO

One of the primary objectives of EDTO is to ensure the safety of passengers and crew in the event of an engine failure. Twin-engine aircraft are commonly used in long-distance flights due to their efficiency and cost-effectiveness. However, the absence of an engine redundancy poses a higher risk compared to larger aircraft with multiple engines.

EDTO regulations establish the minimum requirements for the distance that an aircraft must be from a suitable airport at any given time during the flight. These regulations take into account various factors such as the aircraft’s performance capabilities, weather conditions, and the availability of en-route alternate airports. By setting these requirements, EDTO ensures that twin-engine aircraft always have a suitable airport within reach in case of an emergency.

For example, let’s consider a long-haul flight from New York to London. This route has a significant distance over the Atlantic Ocean where en-route alternate airports may be limited. EDTO regulations would require the aircraft to stay within a certain distance from a suitable diversion airport, ensuring that there is always a viable option for an emergency landing. This not only enhances safety but also provides peace of mind to passengers and crew.

EDTO Certification and Requirements

In order to conduct flights under EDTO regulations, aircraft operators must obtain EDTO certification. This certification is granted by national aviation authorities and is contingent on meeting specific requirements. The certification ensures that the aircraft is equipped with the necessary systems, equipment, and procedures to operate safely during extended diversion times.

The requirements for EDTO certification vary depending on the specific rules and regulations of each aviation authority. However, they generally include the following:

  • Ensuring the reliability and redundancy of critical systems, such as engines and fuel systems.
  • Implementing rigorous maintenance programs to detect and prevent potential issues.
  • Developing comprehensive training programs for flight crew members on EDTO procedures and emergency protocols.
  • Conducting regular inspections and audits to ensure compliance with EDTO regulations.
  • Establishing effective communication and coordination protocols between the flight crew, air traffic control, and company operations.

By meeting these requirements, aircraft operators demonstrate their commitment to safety and their ability to handle situations that may arise during extended diversion times.

Continuous Improvement in EDTO

Over the years, EDTO regulations have evolved to keep up with advancements in aircraft technology, navigation capabilities, and operational practices. Aviation authorities regularly review and update these regulations to ensure that they align with the latest standards and best practices in the industry.

For example, the Federal Aviation Administration (FAA) in the United States introduced the EDTO 180-minute rule in 2007. This rule allowed twin-engine aircraft to fly up to 180 minutes away from a suitable divert airport, further increasing the operational flexibility and efficiency of long-haul flights.

By continuously improving EDTO regulations, aviation authorities aim to strike a balance between safety and operational efficiency. The goal is to enable the aviation industry to meet the growing demands of long-distance travel while ensuring the highest level of safety standards.

As technology continues to advance and aircraft capabilities improve, it is expected that EDTO regulations will further evolve to accommodate these changes.


Extended Diversion Time Operations (EDTO) play a crucial role in ensuring the safety of long-haul flights conducted by twin-engine aircraft. By setting regulations and requirements, EDTO ensures that suitable diversion airports are always within reach in the event of an engine failure.

EDTO certification demonstrates an aircraft operator’s commitment to safety and their ability to handle extended diversion times. It involves meeting specific requirements related to critical system reliability, maintenance programs, training, and communication protocols.

Continued advancements in EDTO regulations, driven by the evolution of aircraft technology and industry best practices, further enhance safety and operational efficiency in long-haul flights. As the aviation industry continues to grow, EDTO will continue to be a cornerstone of safety in the complex world of aviation.

For more information on EDTO and its regulations, you can visit the Federal Aviation Administration (FAA) website.

For More: What is RTOW in Aviation? (Regulatory Take-Off Weight)