Packet Assembler/Disassembler 
Peripheral Arterial Disease 
Peripheral Artery Disease 
Packet Assembler Disassembler 
Program Action Directive 
Program Approval Document 
Project Approval Document 
Pad Abort Demonstration 
Product Assurance Directorate 
Project Appraisal Document 
Propellant Acquisition Device 
Protective Action Decision 
Packet Assembler/Disassember 
Packet Assembly Disassembly 
Peer Authorization Database 
Personal Authentication Device 
Planning and Analysis Division 
Pododermatitis aseptica diffusa 
Point Air Defense 
Polar Auroral Dynamics 
population adjusted dose 
Portable Application Description 
positional adjustment 
precision aircraft direction 
Preferred Arrival Date 
Preliminary Advisory Data 
Program Associated Data 
Programmable Address Decoder 
Project Authorization Document 
Propellant Actuated Device