How Do We Avoid Collisions In Civil Aviation?
After my previous article about the recent mid-air collision between two fighter planes, my editor asked me how we avoid them in civil aviation.
After my previous article about the recent mid-air collision between two fighter planes, my editor asked me how we avoid them in civil aviation.
So here we go.
The basic difference between military flying and commercial aviation is that military flying is extremely challenging, given the nature of the job. And civil flying is much safer, because safety is the primary requirement, right from the design of the airplanes and airports, to the minutest details of operations.
In addition, air traffic controllers manning the radars keep civilian aircraft away from each other, whereas the Fighter Controllers, as they are called in the IAF, bring our interceptors towards the enemy planes.
Unsplash/Representational image
Air traffic¡ªboth civilian and military¡ªis well regulated and everyone involved, pilots and controllers, are well trained. They are also closely monitored, and punishments for mistakes are swift and strict.
And the price to pay is high, sometimes even life itself¡ªat least for the pilots.
On the roads, laws separate the traffic by keeping it on one side of the road. In many countries they keep right, and in India we keep left¡ªmost times!
In the air, different cruise levels separate airplanes. Those going East fly at odd altitudes, at 33000, 35000, 37000 feet, and airplanes going West fly at even altitudes, at 34000, 36000, 38000 feet on the airways.
Yes, like highways, we have airways in the sky, and we fly above and below the reciprocal traffic.
AAI
That works fine in cruise, but cannot work during climb and descent.
All airplanes must take off from a single runway or multiple runways nearby. At some airports the runways are parallel, but at some, they even cross each other. And you cannot place a traffic signal at the crossing!
Google Maps
That is where the skill of the controllers and the pilots comes into play.
Controllers¡¯ instructions are curt, rapid, and precise. And pilots must read back the important parts before following the instructions accurately.
So high is the workload of the controllers that at busy airports they have three controllers on different radio frequencies controlling aircraft in different directions and height bands. And they work for a maximum of 2 hours at a time before they take a compulsory break of 30 minutes.
We pilots, alas, fly much longer, but that¡¯s why we have two in the cockpit.
There are markings at the airports to keep us from entering the runways by mistake, and we have Surface Movement Control radars to track every aircraft on the ground.
And most important, we have a TCAS (Traffic Collision Avoidance System), on board every aircraft that shows us the conflicting traffic, cautions us, and even advises avoidance action.
Unsplash/Representational image
The best part is, TCAS of two conflicting airplanes will co-ordinate their orders to make one plane climb and the other to descend.
We switch it on when we enter the runway for take-off, and we keep it on till we vacate the runway after landing.
Regulators mandated TCAS on all large commercial aircraft worldwide to put a stop to many collision accidents that kept recurring, but a few mid-air collisions happened even after that.
Improvements in the equipment turned two possible collisions into near misses in the last decade.
There has been no collision between civilian airliners after 2006, and that is a tribute to the technology and training, as also to the skill and discipline of the personnel.
We¡¯ll keep an eye on the sky, while you onboard relax and enjoy.
Happy flying!
The writer is a former fighter pilot of the IAF and is now a commercial airline pilot. He is the author of three novels and many blog posts, available at www.avinashchikte.com
