Unable to wear a helmet?

This question arose from a casual discussion amongst non-aviation enthusiast friends, but I think it’s an interesting question.

Given that the wearing of a helmet is necessary for modern combat aircraft pilots, are there any Sikh pilots?
My limited understanding of Sikhism is that adult males must wear a turban, with few, if any exceptions.

AFAIK, Sikhs Police officers in the UK do not have to wear the standard Bobby’s helmet and Sikh soldiers in the Indian Army (& British Army, I think) are also exempt to some degree from wearing standard Army helmets.

I’m sure you guys know the answer to this one. 😉