origin of ‘Mayday’ (international radio distress signal)

The word Mayday, which dates from 1923, is used as an international radio distress signal, especially by ships and aircraft. It was supposedly coined by Frederick Stanley Mockford (1897-1962), a senior radio officer at London’s Croydon Airport, but this has not been substantiated: the fact that this story has often been repeated gives it a semblance of truth but does not authenticate it.

On Friday 2nd February 1923, several English newspapers announced the use of this new signal (but none of them mentioned Mockford); for example, the Gloucestershire Echo (Cheltenham, Gloucestershire):


“S.O.S.” is the international distress signal for telegraphic purposes. In a telephone, however, the sound “S” is very difficult to hear, even under the best conditions, and as all aeroplane traffic is dealt with by wireless telephone, a new international distress signal has been found necessary. For the time being “May-day” has been selected. To English ears such a combination may sound strange, but when it is explained that the words are the phonetic equivalent of “M’Aidez,” the French for “Help me,” the meaning becomes clear.

However, the explanation given in this newspaper is grammatically incorrect because:
– French m’aidez can only occur with the second-person personal pronoun vous, in vous m’aidez (you help me) and m’aidez-vous? (do you help me?)
– the French imperative corresponding to the English imperative help me is aidez-moi.

For these reasons, the word Mayday is more probably from French venez m’aidercome and help me.

On the same day, Friday 2nd February 1923, the Dover Express & East Kent News (Dover, Kent) added the following story:

During a recent test a R.A.F. flying-boat, descending in the Channel, gave the international distress signal three times by wireless telephony and reported that her engines had failed. The message was picked up at Croydon and Lympne. The Civil Aviation Traffic Officer at Lympne telephoned to the Harbour Master at Dover, and within twenty minutes of the distress call a tug from Dover was alongside to give assistance, having steamed about three miles. No special warning had been given to Dover to be ready.