http://www.hmrc.gov.uk/taxtreaties/i.../india-dtc.pdf
Scroll down to section 8 and click on the link to it and it'll take you there.
Section 8 of the India - Uk tax agreement:
Profits derived from the operation of aircraft in international traffic by an enterprise of one of the Contracting States shall not be taxed in the other Contracting State.
There's this updated amendment to the treaty but it is not in force and doesn't affect air transport workers.
http://www.hmrc.gov.uk/taxtreaties/s...-india-dta.pdf
Enjoy India.