etiquette - Is it rude to ask the status of an application?

I have applied for a PhD position in October 2015. I was not informed about the result since then.

Is it appropriate to send a mail to a member of the hiring committee (with whom I have contacted before applying) to ask about the process? Or should I wait for them to contact me?

The university is in Sweden and I have contacted with the member prior to the application since he is the head of the research group that I intend to work in.

Answer

It depends. What does your acknowledgement say when you had submitted your application?

If you were told something like "you will be informed your result by XX month/year" and you have not received anything in that regard by that period, then you can write an e-mail to inquire the status of your application.

If you were told something like "only successful candidates will be informed by XX month/year" and you have not received anything in that matter, then you can write an e-mail to your contact person to know the status.

In any case, you can write email politely to know about your application status if you think it is already too late. There is no harm to inquiring application status.