первинна причина, першопричина
contribute to the cause of peace
deviating cause
cause factor
cause of aircraft trouble
root cause
occurrence cause
trouble cause
determinate cause
eliminate cause
failure cause
second cause
gunner's primary sight (GPS)
officer of primary responsibility
primary (fire) position
primary arm
primary armament
primary burn
primary control surface
primary sector of fire
primary high explosive
primary military occupational specialty (MOS)
primary mission
primary reserve
primary target
primary target line (PTL)
primary trainer
primary weapon
primary position
primary, alternate, contingency, emergency (PACE)
primary level training (PLT)
primary venturi
primary control surfaces