Modern aviation has earned a reputation as the safest mode of transport over the last few decades. Indeed, this is because of several reasons, but coordination between a pilot and air traffic controllers is a major driving force in the safe operation of aircraft. But who has more authority?
Pilots or Air Traffic Controllers?
Naturally, the answer to this question is riddled with a lot of ifs and buts. Regulations say the pilot in command (PIC) will have the final say in all matters concerning the safety of the aircraft and passengers onboard, but that authority doesn’t go unchecked.
The European Aviation Safety Agency’s (EASA) regulations relating to the matter say,
The commander shall have authority to give all commands and take any appropriate actions for the purpose of securing the safety of the aircraft and of persons and/or property carried.”
Indeed, this is the reason why flight attendants will often have to ask the Captain when passengers make unusual requests, like asking for a visit to the flight deck. Or who knows, maybe that’s just a polite way of saying no.
The ifs and buts
Pilots are obligated to follow ATC orders under normal circumstances, without which safe operation would be pretty much impossible. A PIC’s authority to defy ATC instructions is only used in abnormal situations where the safety of the aircraft is at stake. Even then, the pilots will be liable for a satisfactory explanation of their actions when the dust has settled.
For example, when the cabin pressurization warning comes on while flying at 37,000 ft, chances are, the pilots would not have time to request ATC clearance to make a rapid descent. In this particular case, the responsible thing would be to bring the plane down to a safe altitude of 10,000 ft, so passengers can breathe almost normally even if the pressurization system goes kaput.
This is precisely what happened on a recent Virgin Atlantic flight from Manchester to Islamabad in Pakistan. The Airbus A330 operating the flight gave the pilots a pressurization warning, forcing them to initiate a rapid descent to a safe altitude. Chances are, the pilots would have advised the controller of their situation during or after the descent.
Deviating from an ATC order
Pilots aren’t allowed to deviate from ATC orders unless one of three things occurs: the ATC provides an updated order, an emergency exists, or said deviation is in response to a flight warning system like traffic alert or collision avoidance.
On the other hand, when an aircraft squawks 7700 or a pilot declares an emergency, the ATC is required to accommodate the pilot’s needs in every possible way. This includes providing support from emergency services, priority landing, and any other request the pilot may make, no matter how unusual.