Petty Officer Third Class is the fourth enlisted rank in the Federation Starfleet. The rank is higher than a Crewman and lower than a Petty Officer Second Class. The rank is the lowest rank of a non-commissioned Starfleet officer. Personnel having this rank are referred to as Petty Officer Three or PO3 in most circumstances.
Unlike the Crewman and lower ranks, advancement to Petty Officer Third Class is dependent on time served in Starfleet, performance evaluations by superiors, and technical specialty examinations. The advancement cycle is once a year. Only a certain number of billets or job openings for this rank open up annually and all Crewmen compete. The top scorers are chosen for advancement, but only in sufficient quantities to fill the available vacancies.
Petty Officers serve a dual role as both technical experts and as leaders. Unlike the crewmen below them, there is no such thing as an "undesignated Petty Officer." Every petty officer has both a rank and a rating. A petty officer's full title is a combination of the two.
Petty Officer Third Class Ranks[]
| Command-Service | Operations-Service | Sciences-Service | |
|---|---|---|---|
| 2270s | 
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| 2350s | 
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| 2370s | 
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External Links[]
- Petty officer article at Memory Alpha, the canon Star Trek wiki.
- Petty officer article at Memory Beta, the non-canon Star Trek wiki.
- Petty officer third class article at Star Trek Expanded Universe.