<P> Lieutenant commander (also hyphenated lieutenant - commander and abbreviated LCdr, LCdr. or LCDR) is a commissioned officer rank in many navies . The rank is superior to a lieutenant and subordinate to a commander . The corresponding rank in most armies (armed services) and air forces is major, and in the Royal Air Force and other Commonwealth air forces is squadron leader . </P> <P> The NATO rank code is mostly OF - 3 . </P> <P> A lieutenant commander is a senior department officer or the executive officer (second - in - command) on many warships and smaller shore installation, or the commanding officer of a smaller ship / installation . They are also senior department officers in naval aviation squadrons . </P> <P> Most Commonwealth and other navies address lieutenant commanders by their full rank or the positions they occupy ("captain" if in command of a vessel). The United States Navy, however, addresses officers by their full rank or the higher grade of the rank . For example, oral communications in formal and informal situations, a lieutenant (junior grade) is abbreviated as "lieutenant," and a lieutenant commander is abbreviated as "commander ." </P>

What does a lt commander do in the navy
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