KARACHI: The Civil Aviation Authority (CAA) has sought clarification about the security clearance of a German national, Bernd Hildenbrand, who is currently the chief operating officer (COO) of the Pakistan International Airlines (PIA). In a letter written to the national airline, it was said that the security clearance is mandatory under the National Aviation Policy 2015 and prescribed regulations. The CAA said that it has not received any communication from the PIA over the employment and pre-requisite security clearance of the COO and several media reports indicate that it has not been received. The letter requested the PIA to clarify on the status of the security clearance. In case it has not been received, the airline has been requested to initiate proceedings to obtain the security clearance as soon as possible.