On my first trip to India, in 1996, I was startled by signs in banks banning weapons, but with an exception for “short knives for Sikhs.” (This was only one of the many things that startled me during that trip, and on balance was probably one of the least startling startling things, far less weird than, say, burning bodies bobbing in the Ganga or the monkey that leaped onto my dinner plate in Agra. But I digress.) There are those who argue that the kirpan is not a weapon, or at least is not intended as such, but I doubt they’ve convinced airlines and governments in these security-conscious times.
For more information on Sikh legal issues, including the wildly misguided discrimination they’ve faced in the US since 9/11, check out The Sikh Coalition, which includes a section of the USA Patriot Act specifically condemning anti-Sikh discrimination, as well as recommended guidelines for airport personnel dealing with Sikhs. (Should veiled women be required to show their faces to prove their identities? Yes, but a female security guard is preferable. Should Sikhs be permitted to wear the kirpan into the secure section of an airport? No, they should be required to place it in checked luggage.)