How to Avoid Runway Incursions? All You Need to Know
Runway incursions are a major concern for the aviation industry. In this blog post, we will discuss what runway incursions are, the different levels of severity, and how to prevent them. Every year, there are thousands of runway incursions around the world.
Some of these incidents can cause major delays or even accidents. Pilots and airport personnel needs to be aware of the dangers of runway incursions and take steps to avoid them.
From October to December 2021, around 398 incursions took place in the United States as compared to 318 for the same three months the previous year. According to the Federal Aviation Administration, in 2021, there were 1469 incidents of incursions on runways, taxiways, and aprons.
These runway incursions can be placed into categories depending on the level of severity. We will discuss these below.
- What Are Runway Incursions?
- What are the Causes of Runway Incursions?
- What are the Consequences of Runway Incursions?
- How To Prevent Runway Incursions?
- Our Concluding Thoughts
What Are Runway Incursions?
A runway incursion is defined as any unauthorized or unplanned movement by an aircraft, vehicle, or person on a runway that could create a collision hazard. In other words, it is when something or someone enters a runway without clearance from air traffic control.
Many different factors can contribute to a runway incursion which will be discussed later.
The International Civil Aviation Organization defines a runway incursion as "an occurrence at an aerodrome involving the incorrect presence of an aircraft, vehicle or person on the protected area of a runway while another aircraft is taking off or landing."
The aerodrome here refers to the runway and the area around it that is used for takeoffs and landings. The protected area of a runway is the part of the runway that is meant for taking off and landing. This usually includes the runway itself, the taxiway leading up to it, and sometimes a buffer zone around it.
Based on the type and severity of the occurrence, there are many different types of runway incursions. We will discuss the four main categories below based on the severity of the incident.
Category A Runway Incursion
This is the most serious type of runway incursion. It is defined as an incident in which there is a serious risk of collision between two aircraft. This could happen if an aircraft takes off or lands on a runway that another aircraft is already on or if two aircraft are on the runway at the same time and are heading towards each other. In either case, there is a real risk of a collision.
Category B Runway Incursion
This type of runway incursion is less serious than Category A but still poses a significant risk of collision. It is defined as an incident in which an aircraft, vehicle, or person is on a runway without authorization, but there is no risk of collision with another aircraft.
For example, if an unauthorized vehicle or person is on the runway while an aircraft is taking off or landing, there is still a risk of collision, but it is not as high as if two aircraft were on the runway at the same time.
Category C runway incursion
This type of runway incursion is less serious than Categories A and B. It is defined as an incident in which an aircraft, vehicle, or person is on a runway without authorization, but there is no risk of collision, and the airport's operation is not affected.
For example, if an aircraft is taxiing on the runway without clearance from air traffic control, there is still a risk of collision, but it is not as high as if two aircraft were on the runway at the same time.
Category D runway incursion
This type of runway incursion is the least serious. It is defined as an incident in which an aircraft, vehicle, or person is on a runway without authorization, but there is no risk of collision, and the operation of the airport is not affected.
These categories were classified based on several factors such as the available reaction time, environmental conditions, evasiveness of corrective action, and speed and proximity of the aircraft and/or vehicle.
Another classification of runway incursions is operational incidents, pilot deviations, and pedestrian/vehicle deviations.
- Operational incidents are runway incursions that are caused by issues with air traffic control, runway or taxiway design, or airport signage. They usually involve more than one aircraft or vehicle and can be difficult to avoid.
- Pilot deviations are runway incursions that are caused by errors on the part of the pilot. They can be caused by poor judgment, incorrect runway or taxiway information, or miscommunication with air traffic control. Pilot deviations are usually more difficult to avoid than operational incidents.
- Pedestrian/vehicle deviations are runway incursions that are caused by people or vehicles that are not authorized to be on the runway. They can be caused by unauthorized vehicles, people who are trespassing, or wildlife. Pedestrian/vehicle deviations are usually more difficult to avoid than operational incidents.
Prevention of runway incursions is a joint effort between pilots and air traffic controllers. Pilots must follow all ATC instructions and maintain vigilance while taxiing. Air traffic controllers must provide clear and concise instructions to pilots, monitor runway activities, and take action when necessary.
What are the Causes of Runway Incursions?
There are many different causes of runway incursions, but they can generally be classified into three categories: air traffic control, pilot error, and pedestrian/vehicle error.
- Air traffic control errors are the most common cause of runway incursions. They can be caused by incorrect runway or taxiway information, miscommunication with pilots, or incorrect instructions from air traffic control.
- Pilot error is the second most common cause of runway incursions. Pilots can make errors in judgment, fail to follow ATC instructions, or misunderstand runway or taxiway information.
- Pedestrian/vehicle error is the third most common cause of runway incursions. This can be caused by unauthorized vehicles or people on the runway, trespassing, or wildlife.
One of the most infamous incidents of a runway incursion was in 1977, which resulted in two airplanes, a Boeing 747 and a Lockheed L-101, colliding on a runway in Tenerife, Spain. This incident killed all 248 passengers and crew on the Boeing 747 and all 335 passengers and crew on the Lockheed L-101. It is one of the deadliest aviation accidents in history.
On investigation, it was discovered that the accident was caused due to a runway incursion. The Lockheed L-101 was taxiing on the runway without clearance from air traffic control and collided with the Boeing 747 that was taking off. This accident highlights the importance of preventing runway incursions.
Although several years have passed since this incident, runway incursions are still a major concern for the aviation industry. In 2017, there were over 1400 runway incursions reported in the United States alone.
What are the Consequences of Runway Incursions?
The consequences of runway incursions can range from minor delays to serious accidents. In some cases, multiple aircraft or vehicles may be involved in an incident.
The most serious runway incursions can result in a collision between two aircraft, which can lead to multiple fatalities. Runway incursions can also cause significant delays for other aircraft that are using the same runway.
According to a report from Transport Canada in September 2000, the average runway incursion in Canada caused a delay of 13 minutes for other aircraft. The report also found that the majority of runway incursions were caused by air traffic control errors, pilot errors, or pedestrian/vehicle errors.
It also pointed out that due to the increase in air traffic volume, the number of runway incursions was expected to increase in the future.
Therefore, to counter this potential increase, various methods have been adopted:
- One of them is conducting runway operations in parallel, which means that more than one runway can be used for arrivals or departures at the same time. This helps to reduce the chance of runway incursions as it reduces the amount of time that aircraft spend on the runway.
- Another method that has been adopted is installing runway status lights (RWSL) at airports. These are red lights that are installed on the runway and taxiway to indicate when it is unsafe for an aircraft to enter or cross the runway.
- Land and hold short operations (LAHSO) is another runway safety measure that has been put in place at many airports. This involves an aircraft landing and then stopping short of the runway intersection or departure point. The aircraft then holds until it is cleared by air traffic control to proceed.
- Another method is SIRO or simultaneous intersecting runway operations. This is where aircraft land and depart on the intersecting runways at the same time. This is only possible if the runway configuration, aircraft type, and air traffic control procedures allow it.
The FAA has also recommended a few changes to the flight crew and ATC procedures for further mitigation. It has suggested a mandatory read-back of taxi route clearances.
Additionally, it has highlighted the standard ICAO radio phraseology and recommended the use of exterior lighting for enhancing aircraft identification.
How To Prevent Runway Incursions?
Below are a few steps that can be adopted to enhance safety
Safe Taxi Procedures
Basically, it means that the pilots should ensure that they have the correct taxi clearance before moving onto the runway. The read-back of the taxi clearance is a mandatory procedure to avoid any misunderstanding.
Sterile cockpit procedures must be adhered to while the aircraft is on the runway. No non-essential conversation should occur between the crew members when the aircraft is taxiing, taking off, or landing.
The ATC must always be kept in the loop when it comes to runway changes. This is to ensure that the runway is clear and no other aircraft is using it.
Use of Runway Lighting
The runway edge lights, runway end identifier lights, and approach slope indicator lights should always be turned on when operating in low visibility conditions. These help the pilots to identify the runway edges and make a safe landing.
The runway threshold and runway end lights should also be turned on when the runway is wet. This is to help the pilots identify the runway edges in case of a water runway.
Communication and employing key phraseology
It is important to maintain two-way communication with the ATC at all times. This helps to avoid any misunderstanding and ensures that the runway is clear for landing or takeoff.
The use of standard phraseology is also important as it helps to avoid confusion. For instance, pilots should use the phrase "hold short" when they are instructed to stop before entering the runway.
Lining Up and Waiting
The pilots should line up the aircraft on the runway only when they have been given the clearance to do so. They should also wait for the takeoff clearance before starting the takeoff roll.
Monitoring the Flight Deck
The captain or pilot-in-command should always monitor the flight deck and ensure that all procedures are being followed correctly. This is to avoid any runway incursion or collision. In case of any doubt, the captain or PIC should query the ATC for clarification.
Regular Safety Meetings and Awareness
It is important to hold regular safety meetings to discuss any runway incursion or collision. The aim of these meetings is to raise awareness and prevent any future incidents.
This is because runway incursions are a serious safety hazard that can lead to disastrous consequences. It is important to follow all the procedures and take all the necessary precautions to avoid them. Therefore, pilots, staff, crew members, and air traffic controllers must work together to ensure the safety of all.
Our Concluding Thoughts
This blog post attempted to draw light on the runway incursion problem and suggested a few solutions on how to avoid them. While runway incursions are not common, they can have catastrophic consequences if they do occur. Hence, both pilots and air traffic controllers need to be aware of the potential risks and take steps to avoid them.
Runway incursions are a serious safety hazard and should be avoided at all costs. The above are a few steps that pilots and air traffic controllers can adopt to prevent runway incursions.
What other steps do you think can be taken to avoid runway incursions? Let us know in the comments below. Safe flying!