FO
Abbreviation with 4 meanings
| Stands for | First officer |
|---|---|
| Meanings | 4 |
| Categories | Transportation & Travel, Military, Geography & Places |
FO has four meanings. The most common are First officer (aviation) and Flag officer (military term); it can also stand for Forward observer and Faroe Islands.
Meanings of FO at a glance
| # | FO stands for | Context |
|---|---|---|
| 1 | First officer | Transportation & Travel › Aviation |
| 2 | Flag officer | Military › Military Term |
| 3 | Forward observer | Military › Military Term |
| 4 | Faroe Islands | Geography & Places › Country Code |
1. First officer
Transportation & Travel · Aviation Abbreviations
Second pilot on an airliner, seated on the right and sharing flying duties with the captain, typically alternating legs as pilot flying and pilot monitoring. First officers at US airlines must hold an ATP certificate, normally requiring 1,500 flight hours.
Example: The FO flew the leg into Boston while the captain handled the radios and checklists.
First officers usually wear three stripes on their epaulettes versus the captain's four. "Copilot" means the same thing, though airlines prefer the formal title. The US 1,500-hour requirement came from the Airline Safety and FAA Extension Act of 2010, passed after the 2009 Colgan Air Flight 3407 crash near Buffalo.
2. Flag officer
Military · Military Term Abbreviations
Navy and Coast Guard officer in the grades of rear admiral (lower half) through admiral (O-7 to O-10), the sea-service counterpart of a general officer. The term comes from the right to fly a personal flag showing the officer's rank.
Example: Only a FO can serve as commander of a numbered fleet.
Flag officers fly flags with one to four stars when embarked or present at a command. Royal Navy commodores fly a broad pennant rather than a flag, a distinction from US practice. In fire support, FO means forward observer, a completely different role.
3. Forward observer
Military · Military Term Abbreviations
Soldier or Marine who directs artillery and mortar fire onto targets, usually positioned with frontline units where they can see the enemy. In the Army, forward observers hold the military occupational specialty 13F.
Example: The FO adjusted the mortar rounds 100 meters left onto the trench line.
Forward observers send calls for fire with target grids, descriptions and adjustments. Their job is among the most dangerous because enemies target observers. In naval and general staff usage, FO can also mean flag officer.
4. Faroe Islands
Geography & Places · Country Code Abbreviations
Self-governing North Atlantic archipelago within the Kingdom of Denmark, with Tórshavn as its capital and about 54,000 residents. The Faroe Islands are outside the EU and have their own .fo domain.
Example: The ferry from Denmark docks in Tórshavn, FO, after a crossing of about a day and a half.
Faroese is a North Germanic language closely related to Icelandic. The islands have their own football team and stamps. The alpha-3 code is FRO.
Related abbreviations
More aviation abbreviations
- FE – Flight engineer
- FIR – Flight information region
- FL – Flight level
- FMS – Flight management system
- FOD – Foreign object debris
- FSS – Flight service station
- GA – General aviation
- GPU – Ground power unit
See all 142 aviation abbreviations →