(a) In unusual circumstances, the time limits prescribed in §§902.60 and 902.61 may be extended by written notice to the person making the request. The notice shall set forth the reasons for the extension and the date on which a determination is expected to be dispatched. Under no circumstances shall the notice specify a date that would result in an extension for more than 10 workdays.

(b) As used in this section, unusual circumstances means (but only to the extent reasonably necessary to the proper processing of the particular request):

(1) The need to search for, collect and appropriately examine a voluminous amount of separate and distinct records which are demanded in a single request;

(2) The need to search for and collect the requested records from field facilities or other establishments that are separate from the office processing the request; or

(3) The need for consultation, which shall be conducted with all practicable speed, with another agency having a substantial interest in the determination of the request or among two or more components of the agency having substantial subject matter interest therein.

(c) Any person having made a request for records under this part shall have exhausted his administrative remedies with respect to such request, if the Corporation fails to comply with the applicable time limitations set forth in this subject.