| Oak Brook, IL, USA |
QHO |
| Oak Harbor, WA [Oak Harbor Air Park], USA |
ODW |
| Oak Harbor, WA [Whidbey Island Naval Air Station] USA |
NUW |
| Oakland, CA [Coliseum Street], USA |
OBT |
| Oakland, CA [Metropolitan Oakland International Airport],
USA |
OAK |
| Oakland, CA [Oakland Convention Center Heliport], USA |
JCE |
| Oakland, MD [Garrett County Airport], USA |
ODM |
| Oakley, KS [Oakley Municipal Airport], USA |
OEL |
| Oaktown, IN [Green Airport], USA |
OTN |
| Oberlin, KS [Oberlin Municipal Airport], USA |
OIN |
| Ocala, FL [Ocala Regional/Jim Taylor Field Airport], USA |
OCF |
| Ocean City, MD [Ocean City Municipal Airport], USA |
OCE |
| Ocean City, MD [Ocean City Municipal Airport], USA |
OXB |
| Oceanic, AK, USA |
OCI |
| Oceanside, CA [Oceanside Municipal Airport], USA |
OCN |
| Oceanside, CA [Oceanside Municipal Airport], USA |
OKB |
| Oconto, WI [Oconto Municipal Airport], USA |
OCQ |
| Odessa, TX [Odessa-Schlemeyer Field Airport], USA |
ODO |
| Oelwein, IA [Oelwein Municipal Airport], USA |
OLZ |
| Ogallala, NE [Searle Field], USA |
OGA |
| Ogden, UT [Hill Air Force Base], USA |
HIF |
| Ogden, UT [Ogden-Hinckley Airport], USA |
OGD |
| Ogdensburg, NY [Ogdensburg International Airport], USA |
OGS |
| Oil City, PA [Splane Memorial Airport], USA |
OIL |
| Okeechobee, FL [Okeechobee County Airport], USA |
OBE |
| Oklahoma City, OK [Downtown Airpark], USA |
DWN |
| Oklahoma City, OK [Sundance Airpark], USA |
HSD |
| Oklahoma City, OK [Tinker Air Force Base], USA |
TIK |
| Oklahoma City, OK [Wiley Post Airport], USA |
PWA |
| Oklahoma City, OK [Will Rogers World Airport], USA |
OKC |
| Okmulgee, OK [Okmulgee Municipal Airport], USA |
OKM |
| Olathe, KS [New Century Aircenter Airport], USA |
IXD |
| Olathe, KS/Kansas City, MO [Johnson County Executive Airport],
USA |
OJC |
| Olathe, KS/Kansas City, MO [Johnson County Industrial Airport],
USA |
JCI |
| Old Harbor, AK [Old Harbor Airport], USA |
OLH |
| Old Town, ME [Dewitt Field/Old Town Municipal Airport], USA |
OLD |
| Olean, NY [Cattaraugus County/Olean Municipal Airport], USA |
OLE |
| Olga Bay, AK [Olga Bay Seaplane Base], USA |
KOY |
| Olive Branch, MS [Olive Branch Airport], USA |
OLV |
| Olney, TX [Olney Municipal Airport], USA |
ONY |
| Olney-Noble, IL [Olney-Noble Airport], USA |
OLY |
| Olympia, WA [Olympia Airport], USA |
OLM |
| Omaha, NE [Eppley Airfield], USA |
OMA |
| Omaha, NE [Millard Airport], USA |
MIQ |
| Omaha, NE [Millard Airport], USA |
MLE |
| Omaha, NE [Offutt Air Force Base], USA |
OFF |
| Omak, WA [Omak Airport], USA |
OMK |
| Oneida, TN [Scott Municipal Airport], USA |
SCX |
| O'Neill, NE [O'Neill Municipal/John L. Baker Field Airport],
USA |
ONL |
| Oneonta, NY [Oneonta Municipal Airport], USA |
ONH |
| Onion Bay, AK, USA |
ONN |
| Ontario, CA [Ontario Heliport], USA |
JIO |
| Ontario, CA [Ontario International Airport], USA |
ONT |
| Ontario, OR [Ontario Municipal Airport], USA |
ONO |
| Ontonagon, MI [Ontonagon County Airport], USA |
OGM |
| Opa Locka/Miami, FL [Opa Locka Airport], USA |
OPF |
| Opelousas, LA [St. Landry Parish/Ahart Field Airport], USA |
OPL |
| Orange City, IA [Orange City Municipal Airport], USA |
ORC |
| Orange County (Santa Ana), CA [John Wayne/Orange County Airport]
USA |
SNA |
| Orange, CA [Choc Heliport], USA |
JOR |
| Orange, MA [Orange Municipal Airport], USA |
ORE |
| Orange, TX [Orange County Airport], USA |
ORG |
| Orange, VA [Orange County Airport], USA |
OMH |
| Orangeburg, SC [Orangeburg Municipal Airport], USA |
OGB |
| Ord, NE [Evelyn Sharp Field], USA |
ODX |
| Orlando, FL [Orlando Executive Airport], USA |
ORL |
| Orlando, FL [Orlando International Airport], USA |
MCO |
| Orlando/Sanford, FL [Orlando/Sanford Airport], USA |
SFB |
| Ormond Beach, FL [Ormond Beach Municipal Airport], USA |
OMN |
| Oroville, CA [Oroville Municipal Airport], USA |
OVE |
| Orr, MN [Orr Regional Airport], USA |
ORB |
| Ortonville, MN [Ortonville Municipal/Martinson Field Airport],
USA |
VVV |
| Osage Beach, MO [Linn Creek-Grand Glaize Memorial Airport],
USA |
OSB |
| Osceola, WI [L.O. Simenstad Municipal Airport], USA |
OEO |
| Oscoda, MI [Oscoda-Wurtsmith Airport], USA |
OSC |
| Oshkosh, NE [Garden County Airport], USA |
OKS |
| Oshkosh, WI [Wittman Regional Airport], USA |
OSH |
| Oskaloosa, IA [Oskaloosa Municipal Airport], USA |
OOA |
| Ottawa, KS [Ottawa Municipal Airport], USA |
OWI |
| Ottawa, OH [Putnam County Airport], USA |
OWX |
| Otto, NM, USA |
OTO |
| Ottumwa, IA [Ottumwa Industrial Airport], USA |
OTM |
| Ouzinkie, AK [Ouzinkie Airport], USA |
KOZ |
| Owatonna, MN [Owatonna Municipal Airport], USA |
OWA |
| Owensboro, KY [Owensboro-Daviess County Airport], USA |
OWB |
| Oxford, CT [Waterbury-Oxford Airport], USA |
OXC |
| Oxford, MS [University-Oxford Airport], USA |
UOX |
| Oxford, NC [Henderson-Oxford Airport], USA |
HNZ |
| Oxford, OH [Miami University Airport], USA |
OXD |
| Oxnard, CA [Oxnard Airport], USA |
OXR |
| Ozona, TX [Ozona Municipal Airport], USA |
OZA |
