What is a Mayday Call? Understanding Its Role in the Air India Crash and Other Aviation Emergencies

The tragic crash of Air India Flight AI171, a Boeing 787 Dreamliner bound for London Gatwick, has left several questions yet to be answered. The flight, carrying 242 passengers and crew, plummeted into a residential area near Ahmedabad’s Sardar Vallabhbhai Patel International Airport just minutes after takeoff. Moments before the crash, the pilot, Captain Sumeet Sabharwal, issued a “Mayday” call to Air Traffic Control (ATC), signaling a dire emergency, according to Directorate general of Civil Aviation (DGCA). But what exactly is a Mayday call, and why is it so critical in aviation?

What is a Mayday Call?

A Mayday call is an international distress signal used by pilots and ship captains to alert authorities of a life-threatening emergency. In aviation, it’s the most urgent cry for help, reserved for situations where the aircraft, crew, or passengers are in immediate danger. The word “Mayday” is repeated three times—“Mayday, Mayday, Mayday”—to ensure it’s heard clearly over radio communications, even if the signal is weak or noisy.

The term comes from the French phrase “m’aider,” which means “help me.” It was coined in the early 1920s by Frederick Stanley Mockford, a radio officer at London’s Croydon Airport, to create a clear, universally understood distress call. By 1927, it was officially adopted worldwide, replacing the Morse code “SOS” for voice communications.

When a pilot issues a Mayday call, it instantly grabs the attention of Air Traffic C, who prioritise the aircraft above all other traffic. The pilot typically follows the call with key details, such as the nature of the emergency (e.g., engine failure or fire), the aircraft’s location, and the number of people on board. This triggers an immediate response from emergency services.

In the case of Air India Flight AI171, Captain Sabharwal’s ‘Mayday’ call was the last communication received by ATC before the plane lost contact and crashed in the Meghaninagar area. A fifty nine second video that has surfaced show that the Air India Boeing 787 Dreamliner took off and was on ascent for merely thirteen seconds before it failed to lift itself any further, for reasons still under investigation, began descending and finally crashed into the residential area.

Why is a Mayday Call Important?

For the average person, a Mayday call can be thought of as an urgent 911 call in the sky. It’s a pilot’s way of saying, “We’re in serious trouble, and we need help now.” The call ensures that everyone—ATC, nearby aircraft, and ground crews—knows the situation is critical. It clears the radio frequency of non-emergency chatter and focuses all resources on saving lives.

History of Mayday Calls in Other Air Crashes

The Mayday call has been a lifeline in countless aviation emergencies worldwide. Here are two recent examples where pilots issued Mayday calls during major air crashes:

1. Ethiopian Airlines Flight ET302 (March 10, 2019): On March 10, 2019, a Boeing 737 MAX 8 operating as Ethiopian Airlines Flight ET302 crashed six minutes after takeoff from Addis Ababa, Ethiopia, killing all 157 people on board. The pilots reported control issues and issued a ‘Mayday’ call to ATC, indicating they were struggling to stabilise the aircraft. Data later revealed that a faulty sensor triggered the plane’s automated system to push the nose down repeatedly, leading to the crash. The Mayday call alerted ATC to the emergency, though the rapid descent left little time for intervention. This incident, along with a similar Lion Air crash in 2018, led to the global grounding of the 737 MAX.

2. Pakistan International Airlines Flight PK8303 (May 22, 2020): On May 22, 2020, an Airbus A320 operating as Pakistan International Airlines Flight PK8303 crashed near Karachi, Pakistan, killing 97 of the 99 people on board. The pilots issued a ‘Mayday’ call after reporting engine failure during a second landing attempt. The call was made as the aircraft lost power and descended rapidly into a residential area. The Mayday transmission helped ATC coordinate emergency response teams, which saved two passengers and mitigated ground casualties. Investigations later pointed to pilot error and engine damage as contributing factors.

These examples highlight the ‘Mayday’ call’s role in signalling catastrophic events, even when outcomes are tragic. Like Air India Flight AI171, these crashes involved sudden, severe emergencies that left pilots with little time to act beyond issuing the distress call.

The Aftermath and Investigation

The Air India crash has raised questions about what went wrong. Initial reports suggest a possible engine failure or loss of thrust, as indicated by an ACARS message stating “loss of thrust, no lift.” The Directorate General of Civil Aviation (DGCA) has launched an investigation, focusing on recovering the black box (flight data recorder and cockpit voice recorder) to reconstruct the final moments. The ‘Mayday’ call will be a key piece of evidence, providing insight into the crew’s actions and the nature of the emergency. As India grieves, the Mayday call serves as a reminder of the split-second decisions pilots make in life-or-death situations. It’s a universal plea for help that transcends borders, uniting the aviation community in its mission to prioritise safety.​