I was on holiday this August and travelled with Thomson for package holiday.
Included flights on Thomsonfly/Britannia return.
On return flight back to LGW, we were taxiing out to the active runway in Turkey, and the flight deck door was still OPEN!
I am sure that this is a serious security fault and I believe that the flight deck door should be locked before boarding? This has not happened before on any airline that I have travelled on.