Mumbai, Apr 28 (IANS): In a bizarre development, at least half a dozen IndiGo pilots were detected to have misused an Emergency Frequency to discuss salary issues with objectionable language, according to sources here on Thursday.

The alleged incident took place on April 9 when the pilots were reportedly overheard airing their ire with rude language on the 121.5MHz frequency, that is reserved for use only during emergency communications in times of flight risks.

The Directorate General of Civil Aviation has taken strong cognisance of the indiscretion of the pilots and initiated a probe into the matter, as the emergency frequency is monitored closely by the Air Traffic Control.

Confirming the same, IndiGo official sources told IANS that "the airline was made aware of the matter and it is now with the regulator to take appropriate action".

It is not immediately clear what may have prompted the pilots to use the emergency frequency instead of the 123.45MHz frequency used by them to communicate with other pilots.

However, in the first week of Aprilm IndiGo had suspended a few pilots who were planning to go on a strike on April 5 to protest against pay cuts of around 30 per cent effected by the airline during the Covid-19 pandemic, and was in the process of restoring the salaries gradually in April and later in November if there were no disruptions in flight operations.