Airline pilots are known to be high fliers, professionally and socially, but the Directorate General of Civil Aviation (DGCA) is not amused that many pilots have recently been found "high" on duty.

"During last one year, total number of 42 alcohol positive cases were detected," the DGCA said.

This information has been provided by the DGCA in reponse to an RTI query by Abhishek Shukla who sought details of pilots found drunk on duty.

The DGCA did not give any details of the pilots or the names of the airlines involved, except to say that action "is taken against the crew members as per regulatory provisos."

The DGCA is the regulatory body for civil aviation in India and is responsible for ensuring safety of operations.

Drunkenness among pilots directly impacts flight safety and aviation authorities around the world, including the International Civil Aviation Organisation, mandate a zero tolerance to alcohol where pilots and cabin crew are concerned, experts say.

In response to the RTI questions, the DGCA did not specify whether the pilots were detected before they boarded the aircraft and whether they were prevented from operating a flight after alcohol was detected in their blood sample.

The nature of the action taken against the pilots was also not revealed.

Alcohol in the blood of pilot as well as cabin crew is a serious flight safety issue, experts say.

"The rules prescribe that there shall be no trace of the alcohol in the blood of the pilot and the cabin crew. Alcohol in the blood numbs the senses and dulls the reflexes and increases response time. The effect of alcohol is much more at high altitudes," former director general civil aviation Kanu Gohain told PTI.

Rule 24 of Aircraft Rules prohibits crew members from taking any alcoholic drink 12 hours prior to the commencement of a flight.

Any crew member who tests positive in the pre-flight medical check or refuses to take a breath analyser test is required to be taken off flying duty for at least four weeks and the airline is required to initiate disciplinary proceedings.

In case of any accident or a near-miss, it is mandatory to test the pilot and co-pilot for traces of alcohol.

Alcohol testing is mandatory for pilots and cabin crew but airlines which conduct these tests are often quite lenient with the erring pilots so as not to affect flight schedules, say aviation experts who are not willing to be named.

The DGCA therefore conducts random surprise checks on pilots, pre-flight and post-flight, to ensure that the no-alcohol rule is not violated. This frequency of this cat and mouse game generally increases during Christmas and New Year.

In the past there have been some instances of doctors signing blank clearance forms and pilots just filling in their names just before the flight, experts recall.

"The job requires high skills and presence of mind and there is a need for total honesty to ensure that cabin crew and cockpit crew is in best condition...but DGCA cannot be everywhere and test everone...We require some sort of honesty from airline managements," Gohain said.