An Air India Boeing7878 (Flight AI171), bound for London with 242 souls, issued a Mayday call shortly after taking off from Ahmedabad on Thursday. The plane crashed near the airport, plummeting into buildings and engulfing the Meghani area in thick black smoke. Emergency services raced in as the crew’s urgent signal transformed a routine flight into a tragedy.
The tragic event has brought renewed focus on aviation distress signals — those urgent calls like ‘Mayday’ and ‘Pan-Pan’ that can mean the difference between life and death. Here are five such signals you should know about along with how they began and well-known use cases:
1. MAYDAY
Introduced: 1923 at Croydon Airport (UK), and adopted universally in 1927.
Why it’s used: Repeated thrice — “Mayday, Mayday, Mayday”—it instantly commands absolute priority from all communication channels.
Famous use: On US Airways Flight 1549 in 2009 (‘Miracle on the Hudson’), Captain Sully Sullenberger declared Mayday before landing on the Hudson, saving all onboard.
2. PANPAN
Introduced: Standardised in 1927 alongside Mayday.
Why it’s used: Signals an urgent situation — not yet life-threatening, but needing attention (like engine trouble or medical issues).
Famous use: Swissair Flight 111 declared ‘PanPan’ due to electrical fire before issuing Mayday, ensuring correct escalation of the situation.
3. SOS
Introduced: International Morse code distress call in 1908 (first proposed in 1905).
Why it’s used: A repeated Morse pattern (…—…) easily recognised under duress, it remains iconic in maritime rescues.
Famous use: Titanic radio operators used both CQD and then SOS after hitting an iceberg in 1912, signalling nearby ships for emergency rescue.
4. CQD
Introduced: 1904 by Marconi as the first radio distress call.
Why it’s used: ‘CQ’ meant “calling all stations,” and adding ‘D’ meant distress.
Famous use: SS Republic sent a CQD in 1909. Titanic used the CQD alongside SOS.
5. SCURIT
Introduced: Standard voice call alongside Mayday/PanPan.
Why it’s used: Warns of safety information (weather alerts, navigational hazards), not distress.
Famous use: Regularly used during maritime exercises and safety broadcasts. It’s rarely seen in dramatic news, but it’s vital for safe operations.
These distress signals created a universal language for emergencies — cutting through panic with clarity. Whether it’s a jet in flames or a ship sinking, one word can at times save lives.