Frederick Stanley Mockford’s gravestone at Selmeston, East Sussex, England – photograph: Geoffrey Gillon/Find A Grave
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 make it true.
On 2nd February 1923, several English newspapers announced the use of this new signal (but none of them mentioned Mockford); for example, the Gloucestershire Echo:
“MAY-DAY” FOR S.O.S.
A NEW INTERNATIONAL DISTRESS SIGNAL.
“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, m’aidez can only be part of a sentence such as vous m’aidez?, do you help me?. The imperative aidez-moi translates help me. The word Mayday is more probably from venez m’aider, come and help me.
On the same day, the Dover Express & East Kent News added the following:
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.