Mayday

{{Short description|Emergency procedure word used internationally as a distress signal}} {{about|the distress signal|the holidays celebrated on 1 May|May Day|other uses}} {{Use dmy dates|date=February 2025}}

'''Mayday''' is an emergency procedure word used internationally as a distress signal in voice-procedure radio communications.

It is used to signal a life-threatening emergency primarily by aviators and mariners, but in some countries local organizations such as firefighters, police forces, and transportation organizations also use the term. Convention requires the word be repeated three times in a row during the initial emergency declaration ("Mayday, mayday, mayday").

==History== The "mayday" procedure word was conceived as a distress call in the early 1920s by Frederick Stanley Mockford, officer-in-charge of radio at Croydon Airport, England. He had been asked to think of a word that would indicate distress and would easily be understood by all pilots and ground staff in an emergency.<ref>{{cite web|title=It's MayDay – But That Means Trouble for Aviators|date=May 2017|url=http://yorkshireairmuseum.org/journal/its-mayday-but-that-means-trouble-for-aviators/|access-date=31 March 2018|archive-date=24 March 2019|archive-url=https://web.archive.org/web/20190324195512/http://yorkshireairmuseum.org/journal/its-mayday-but-that-means-trouble-for-aviators/|url-status=dead}}</ref><ref>{{cite book |first1=Bob |last1=Learmonth |first2=Joanna |last2=Nash |first3=Douglas |last3=Cluett |year=1977 |title=The First Croydon Airport 1915–1928 |publisher=London Borough of Sutton Libraries and Arts Services |place=Sutton |isbn=978-0-9503224-3-8 |page=55 }}</ref> Since much of the air traffic at the time was between Croydon and Le Bourget Airport in Paris, he proposed the term "mayday", the phonetic equivalent of the French {{lang|fr|m'aider}}.

The phrase itself does sacrifice grammatical accuracy (meaning literally "to help me") in favour of communicability and recognition. Looking through the lens of French grammar, it may be a short form of {{lang|fr|venez m'aider}}, "come help me".<ref>{{OED|Mayday}}</ref><ref>{{cite web|url=https://en.oxforddictionaries.com/definition/mayday|archive-url=https://web.archive.org/web/20170617112032/https://en.oxforddictionaries.com/definition/mayday|url-status=dead|archive-date=17 June 2017|title=Mayday – Definition of Mayday in English by Oxford Dictionaries|website=Oxford Dictionaries – English|access-date=31 August 2020}}</ref> ''Venez m'aider'' is the closest phonetic phrase to "mayday", but the technically accurate standalone reflexive imperative conjugation would be ''aidez-moi''.

Following tests, the new procedure word was introduced for cross-Channel flights in February 1923.<ref name="times1923">{{cite news |title=New air distress signal |newspaper=The Times |date=2 February 1923 |issue=43255 |page=7 }}</ref> The previous distress call had been the Morse code signal SOS, but this was not considered suitable for voice communication, "[o]wing to the difficulty of distinguishing the letter 'S' by telephone".<ref name="times1923"/> In 1927, the International Radiotelegraph Convention of Washington, D.C. adopted the voice call "mayday" as the radiotelephone distress call in addition to the SOS radiotelegraph (Morse code) signal.<ref>{{cite book |url=http://search.itu.int/history/HistoryDigitalCollectionDocLibrary/4.39.43.en.100.pdf |title=International Radiotelegraph Convention of Washington, 1927 |chapter=Article 19: Distress, alarm, urgency, and safety signals |publisher=HMSO |location=London |year=1929 |orig-date=1928 |pages=80–89 |access-date=9 January 2021 |archive-date=15 January 2021 |archive-url=https://web.archive.org/web/20210115192356/http://search.itu.int/history/HistoryDigitalCollectionDocLibrary/4.39.43.en.100.pdf |url-status=live }}</ref>

==Mayday calls== {{anchor|Mayday relay}} [[File:MV Summit Venture Mayday Call.flac|thumb|A maritime example: The actual mayday call made by {{MV|Summit Venture}} when it collided with the Sunshine Skyway Bridge in 1980, causing the bridge to collapse.]] thumb|A noise-reduced, condensed version of the above {{MV|Summit Venture}} collision call. If a mayday call cannot be sent because a radio is not available, a variety of other distress signals and calls for help can be used. Additionally, a mayday call can be sent on behalf of one vessel by another; this is known as a mayday relay.

Civilian aircraft making a mayday call in the United States airspace are encouraged by the Federal Aviation Administration to use the following format, omitting any portions as necessary for expediency or where they are irrelevant (capitalization as in the original source):

{{blockquote|Mayday, Mayday, Mayday; (Name of station addressed); Aircraft call sign and type; Nature of emergency; Weather; Pilot's intentions and/or requests; Present position and heading, or if lost then last known position and heading and time when the aircraft was at that position; Altitude or Flight level; Fuel remaining in minutes; Number of people on board; Any other useful information.<ref>Aeronautical Information Manual, paragraph 6-4-2, "Obtaining Emergency Assistance", Federal Aviation Administration, 1999.</ref>}}

Making a false distress call is a criminal offence in many countries, punishable by a fine, restitution, and possible imprisonment.<ref>{{cite web|url=https://www.uscg.mil/hq/cg5/cg534/sarfactsinfo/SARisNOjoke.asp|archive-url=https://web.archive.org/web/20170516171604/https://www.uscg.mil/hq/cg5/cg534/sarfactsinfo/SARisNOjoke.asp|url-status=dead|archive-date=2017-05-16|title=Search and Rescue is NO JOKE!|publisher=United States Coast Guard|date=2016-12-21}}</ref>

==Other urgent calls==

===Pan-pan=== {{main|Pan-pan}}

"Pan-pan" (from French: ''{{lang|fr|panne}}'', "a breakdown") indicates an urgent situation of a lower order than a "grave and imminent threat requiring immediate assistance", such as a mechanical failure or a medical problem. The suffix "medico" originally was to be added by vessels in British waters to indicate a medical problem ("pan-pan medico", repeated three times), or by aircraft declaring a non-life-threatening medical emergency of a passenger in flight, or those operating as protected medical transport in accordance with the Geneva Conventions.<ref>ICAO Annex 10 V2 Section 5.3</ref> "Pan-pan medico" is no longer in official use.<ref name="Tim Bartlett 2009 53">{{cite book|title=VHF handbook|author=Tim Bartlett|publisher=The Royal Yachting Association|year=2009|page=53|location=Southampton|isbn=978-1-905104-03-1}}</ref>

===Declaring emergency=== Sometimes the phrase "declaring emergency" is used in aviation, as an alternative to calling "mayday".<ref>{{cite web|url=http://www.ntsb.gov/ntsb/GenPDF.asp?id=DCA05MA003&rpt=fa|archive-url=https://web.archive.org/web/20100915034443/http://www.ntsb.gov/ntsb/GenPDF.asp?id=DCA05MA003&rpt=fa|title=National Transportation Safety Board FACTUAL REPORT AVIATION|url-status=dead|archive-date=15 September 2010|date=15 September 2010}}</ref> For example, in 1998 Swissair Flight 111 radioed "Swissair one-eleven heavy is declaring emergency" after their situation had worsened, upgrading from the "pan-pan" which was declared earlier.<ref>{{cite web|url=https://aviation-safety.net/investigation/cvr/transcripts/atc_sr111.php|title=Aviation Safety Network > Accident investigation > CVR / FDR > Transcripts > ATC transcript Swissair Flight 111 - 02 SEP 1998|first=Harro|last=Ranter|website=aviation-safety.net|access-date=10 February 2019|archive-date=25 August 2019|archive-url=https://web.archive.org/web/20190825144346/https://aviation-safety.net/investigation/cvr/transcripts/atc_sr111.php|url-status=live}}</ref>

However, the International Civil Aviation Organization recommends the use of the standard "pan-pan" and "mayday" calls instead of "declaring an emergency".<ref>{{cite web|title=ICAO Standard Phraseology|url=http://www.skybrary.aero/bookshelf/books/115.pdf|work=SKYbrary|access-date=13 June 2013|archive-date=29 December 2018|archive-url=https://web.archive.org/web/20181229072920/https://www.skybrary.aero/bookshelf/books/115.pdf|url-status=live}}</ref> Cases of pilots using phrases other than "pan-pan" and "mayday" have caused confusion and errors in aircraft handling.<ref>{{cite web|title=Aircraft Fuel Status and Communication Procedures|url=http://www.hkatc.gov.hk/HK_AIP/aic/AIC21-12.pdf|publisher=Hong Kong Civil Aviation Department|access-date=13 June 2013|archive-date=8 August 2017|archive-url=https://web.archive.org/web/20170808151554/http://www.hkatc.gov.hk/HK_AIP/aic/AIC21-12.pdf|url-status=dead}}</ref>

===Silencing other communications traffic=== {{See also|Radio silence}} "Seelonce mayday" (using an approximation of the French pronunciation of ''{{lang|fr|silence}}'') is a demand that the channel only be used by the vessel/s and authorities involved with the distress. The channel may not be used for normal working traffic until "seelonce feenee" is broadcast. "Seelonce mayday" and "seelonce feenee" may only be sent by the controlling station in charge of the distress. The expression "stop transmitting – mayday" is an aeronautical equivalent of "seelonce mayday". "Seelonce distress" and "prudonce" are no longer in use since ITU WRC-07.{{citation needed|date=January 2024}}

The format for a "seelonce mayday" is MAYDAY, All Stations x3 or [Interfering station] x3, this is [controlling station], SEELONCE MAYDAY.<ref name="ITU-RR-2016">{{cite web |title=Radio Regulations, edition of 2016 |url=http://handle.itu.int/11.1004/020.1000/1.43 |website=ITU |publisher=International Telecommunication Union (ITU) |access-date=23 June 2023 |archive-date=25 September 2024 |archive-url=https://web.archive.org/web/20240925015120/https://www.itu.int/en/history/Pages/RadioRegulationsA.aspx?reg=1.43 |url-status=live }}</ref>

"Seelonce feenee" (from French ''{{lang|fr|silence fini}}'', 'silence finished') means that the emergency situation has been concluded and the channel may now be used normally. "Distress traffic ended" is the aeronautical equivalent of "seelonce feenee".<ref>{{cite web|url=https://www.egmdss.com/gmdss-courses/mod/resource/view.php?id=67|title=DISTRESS alert (GMDSS)|first=Spinaker|last=d.o.o|website=egmdss.com|access-date=20 July 2018|archive-date=16 April 2017|archive-url=https://web.archive.org/web/20170416094125/http://www.egmdss.com/gmdss-courses/mod/resource/view.php?id=67|url-status=live}}</ref>

The format for the "seelonce feenee" is MAYDAY, All stations x3, this is [controlling station] x3, date and time in UTC, distressed vessel's MMSI number, distressed vessel's name, distressed vessel's call sign, SEELONCE FEENEE.<ref name="ITU-RR-2016" />

==References== {{Reflist}}

==External links== * [http://www.sailonline.com/seamanship/general-seamanship/distress-calls-at-sea Handling Distress and Help Calls] * [https://web.archive.org/web/20110718041052/http://jcs.dtic.mil/j6/cceb/acps/acp135/ACP135F.pdf ACP135(F): Communications Instructions: Distress and Rescue Procedures] * [https://web.archive.org/web/20130103071227/http://www.boatingsafety.com/vhf1.htm Boating Safety: A VHF Primer, the use and misuse of the VHF] * {{YouTube| 9KhZwsYtNDE|Dead passenger on plane after bird strikes}} * [https://web.archive.org/web/20120331125636/http://www.tc.gc.ca/publications/BIL/TP9878/PDF/HR/TP9878.PDF Transport Canada: Radio Distress Procedures Card TP9878]

{{DEFAULTSORT:Mayday (Distress Signal)}} Category:Emergency communication Category:History of air traffic control Category:International telecommunications Category:Rescue Category:Distress signals Category:Telecommunications-related introductions in 1923