Fieldwork clearance interviews will take place once you have submitted their research proposal portfolio. You will be interviewed by the PhD Committee, and asked questions about your fieldwork, and the proposal you have submitted.
At the start of the interview you may be asked to give a short summary of your project; and you may be asked about any aspect of your research that is covered in (or omitted from!) your proposal.
You should be prepared to defend your choice of topic, field location, theoretical background, choice of research methods, the adequacy of your research training, the feasibility of completion within the time limit. At the same time the interview is an occasion at which you can air issues with the PhD Committee. The Committee has a particular interest in the practicalities of the project, and is prepared (within reason) to offer advice.
Fieldwork clearance interviews are not merely a formality. Students are sometimes required to rewrite all or parts of their proposal, and to resubmit the revised text to the PhD Committee for approval. A second interview may be required. Registration for the PhD, and thus continuation of the course, is dependant on approval from the PhD Committee.
While most revised proposals are approved, this is not automatic, and some proposals are rejected at this stage. The amount of time required for rewriting varies, but two months is not unusual. It is therefore not advisable for students to make inflexible travel or accommodation arrangements before they have been informed of the result of their fieldwork clearance interview. Anyone booking a flight, only to find that they have to remain in Cambridge, risks losing the money they have spent. If they do this, it is at their own risk. The PhD Committee will not consider any such circumstances when it considers fieldwork proposals.