How Planes Flying Avoid Mid-Air Collisions

In an earlier article, I talked about how busy our skies can be. With Flightradar24, we can see that around 20,000 planes can be in the air at once, flying faster than 800 kph at various heights. So you might be curious, how do these planes avoid mid-air collisions?

That’s what I’ll talk about in this article. But before I start, let’s discuss what mid-air collisions are and why they can happen between planes.

The Reality of Mid-Air Collisions

Contrary to what some may think, mid-air collisions between aircraft are rare events. These unfortunate incidents happen when two or more planes come into accidental contact during flight. They are likely to cause extreme damage or even total destruction of the aircraft involved. Many factors could lead to such collisions, including miscommunication, mistrust, and a lack of collision-avoidance systems.

Collision occurrences increase in the vicinity of airports, given the high volumes of aircraft maneuvering in relatively close quarters. The Air Safety Foundation states that 45% of mid-air collisions occur when planes are in a traffic pattern, especially during the final approach or over the runway.

Historical Perspective

Mid-air collisions have been a concern since the early days of aviation. The first recorded collision took place at the Milano Circuito Aereo Internazionale meeting in Italy, back in 1910. Both pilots survived, but the accident left a permanent mark on the history of aviation safety.

Unfortunately, the first fatal collision happened only two years later, in 1912, over France, killing both pilots. These historical events highlight the importance of aviation safety and the need for effective measures to prevent mid-air collisions.

Avoiding Close Calls

In a typical year, there are around 200 near mid-air collisions and between 15 and 25 actual mid-air collisions. A large percentage of these incidents result in fatalities. It’s crucial to note that most near-misses or actual collisions involve military aircraft or private planes. Commercial airlines adhere to stringent separation rules throughout various flight phases.

When it comes to avoiding close calls, vertical separation is a significant factor. When flying below 29,000 feet, commercial aircraft are required to maintain a vertical separation of at least 1,000 feet. This distance increases to 2,000 feet at higher altitudes. In certain airspaces between 29,000 and 41,000 feet, modern equipped aircraft only need to maintain a vertical separation of 1,000 feet.

Traffic Collision Avoidance System (TCAS)

One of the most effective tools in preventing mid-air collisions is the Traffic Collision Avoidance System (TCAS). Introduced in the United States in the 1990s and in Europe in 2000, the system is now an essential feature of all passenger aircraft.

TCAS is a radio system that transmits a signal detailing the plane’s altitude, direction, and airspeed. If another aircraft is detected within an unsafe range, a cockpit voice recorder alerts the pilot with a distinct “traffic! traffic!” warning. This prompts the pilot to look out for visual signs of another plane.

If the aircraft continue to approach each other, the TCAS issues an advisory on whether to climb or descend. Pilots are trained to follow these instructions even if they contradict air traffic control directives. This is due to the TCAS’s superior speed in reacting to the situation and making decisions.

The prevention of mid-air collisions is a complex and multifaceted issue. The aviation industry has made tremendous strides in improving aviation safety such as more stringent air laws and the invention of the Traffic Collision Avoidance System. It is an assurance that despite the complexities and challenges of air travel, every effort is being made to keep our skies safe.