What is RESA in Aviation? (Runway End Safety Area)

What is a Runway End Safety Area (RESA)?

A Runway End Safety Area (RESA) is an essential component of airport infrastructure that plays a crucial role in ensuring the safety of aircraft operations. It refers to the designated area at the end of a runway that provides a buffer zone to minimize the risk of aircraft overrunning the runway during takeoff or landing. The RESA is specifically designed to enhance safety by providing an additional margin of protection in case an aircraft undershoots, overruns, or veers off the runway.

The International Civil Aviation Organization (ICAO) defines the RESA as a defined surface adjacent to the end of a runway prepared or suitable for reducing the risk of damage to an aircraft undershooting or overrunning the runway. The dimensions of the RESA may vary depending on the category of the runway and the type of aircraft using it. Generally, it extends beyond the runway threshold and is typically made of a flat, clear, and obstacle-free surface.

Importance of Runway End Safety Areas

Runway End Safety Areas are critical for enhancing aviation safety and mitigating the potential consequences of runway excursions. Here are some key reasons why RESAs are of utmost importance:

Prevention of runway overruns: RESAs provide a cushioned area for aircraft to decelerate or come to a stop in case they are unable to stop within the designated runway length. This helps prevent accidents caused by runway overruns, which can lead to significant damage to the aircraft, injuries, and even loss of life.
Protection against undershoots: In certain situations, an aircraft may not attain the desired landing point on the runway, leading to an undershoot. The RESA acts as a safety net, allowing the aircraft to land safely even if it falls short of the intended touchdown zone.
Enhanced emergency response: The presence of a RESA facilitates emergency response in the event of an aircraft excursion. It provides additional space for emergency vehicles and personnel to operate, enabling prompt and effective rescue and evacuation operations.

It is important to note that the RESA is not meant for routine aircraft operations. Its purpose is to serve as a protective measure for exceptional circumstances when an aircraft is unable to stop within the designated runway area.

Requirements and Standards for RESAs

The dimensions and design of RESAs are regulated by international aviation authorities to ensure a consistent level of safety across airports worldwide. The ICAO sets forth guidelines for RESAs, and each country's aviation regulatory body may have its own specific requirements. Here are some general principles and standards governing RESAs:

Length requirements: The minimum length of the RESA depends on various factors, including the category of the runway, the approach speed of aircraft, and the airplane performance characteristics. For example, runways serving larger aircraft typically require longer RESAs to accommodate their higher speeds and potential stopping distances.
Surface characteristics: The RESA should have a surface capable of supporting an aircraft's weight and should be free from obstructions. It is typically composed of materials like concrete, asphalt, or engineered materials designed to provide adequate friction and prevent excessive aircraft deceleration.
Markings and lighting: RESAs are often marked with visual aids to enhance their visibility, especially during low visibility conditions. These may include painted markings, lighting systems, or other signage to alert pilots to the presence and boundaries of the RESA.

It is crucial for airports and aviation authorities to adhere to these standards to ensure the effectiveness of RESAs in promoting aviation safety.