Nonstop flight route between St. Helens, Tasmania, Australia and Sidney, Montana, United States:
Departure Airport:
(41°20'12"S by 148°16'54"E)
Arrival Airport:
(47°42'24"N by 104°11'32"W)
Distance from HLS to SDY:
8,971.45 miles (14,438.12 km)
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Jump to:
- About this route
- HLS Airport Information
- SDY Airport Information
- Facts about HLS
- Facts about SDY
- Map of Nearest Airports to HLS
- List of Nearest Airports to HLS
- Map of Furthest Airports from HLS
- List of Furthest Airports from HLS
- Map of Nearest Airports to SDY
- List of Nearest Airports to SDY
- Map of Furthest Airports from SDY
- List of Furthest Airports from SDY
About this route:
A direct, nonstop flight between St Helens Airport (HLS), St. Helens, Tasmania, Australia and Sidney-Richland Municipal Airport (SDY), Sidney, Montana, United States would travel a Great Circle distance of 8,971 miles (or 14,438 kilometers).
A Great Circle is the shortest distance between 2 points on a sphere. Because most world maps are flat (but the Earth is round), the route of the shortest distance between 2 points on the Earth will often appear curved when viewed on a flat map, especially for long distances. If you were to simply draw a straight line on a flat map and measure a very long distance, it would likely be much further than if you were to lay a string between those two points on a globe. Because of the large distance between St Helens Airport and Sidney-Richland Municipal Airport, the route shown on this map most likely appears curved because of this reason.
Try it at home! Get a globe and tightly lay a string between St Helens Airport and Sidney-Richland Municipal Airport. You'll see that it will travel the same route of the red line on this map!
Departure Airport Information:
| IATA / ICAO Codes: | HLS / YSTH |
| Airport Name: | St Helens Airport |
| Location: | St. Helens, Tasmania, Australia |
| GPS Coordinates: | 41°20'12"S by 148°16'54"E |
| Operator/Owner: | Break O'Day Council |
| Airport Type: | Public |
| Elevation: | 158 feet (48 meters) |
| # of Runways: | 1 |
| View all routes: | Routes from HLS |
| More Information: | HLS Maps & Info |
Arrival Airport Information:
| IATA / ICAO Codes: | SDY / KSDY |
| Airport Name: | Sidney-Richland Municipal Airport |
| Location: | Sidney, Montana, United States |
| GPS Coordinates: | 47°42'24"N by 104°11'32"W |
| Area Served: | Sidney, Montana |
| Operator/Owner: | Sidney Richland Airport Authority |
| Airport Type: | Public |
| Elevation: | 1985 feet (605 meters) |
| # of Runways: | 2 |
| View all routes: | Routes from SDY |
| More Information: | SDY Maps & Info |
Facts about St Helens Airport (HLS):
- Because of St Helens Airport's relatively low elevation of 158 feet, planes can take off or land at St Helens Airport at a lower air speed than at airports located at a higher elevation. This is because the air density is higher closer to sea level than it would otherwise be at higher elevations.
- St Helens Airport (HLS) currently has only 1 runway.
- The closest airport to St Helens Airport (HLS) is Launceston Airport (LST), which is located 57 miles (92 kilometers) WSW of HLS.
- The furthest airport from St Helens Airport (HLS) is Corvo Airport (CVU), which is nearly antipodal to St Helens Airport (meaning St Helens Airport is almost on the exact opposite side of the Earth from Corvo Airport), and is located 12,317 miles (19,823 kilometers) away in Corvo Island, Azores, Portugal.
Facts about Sidney-Richland Municipal Airport (SDY):
- The closest airport to Sidney-Richland Municipal Airport (SDY) is Sloulin Field International Airport (ISN), which is located 41 miles (67 kilometers) NE of SDY.
- Scheduled air service temporarily ceased on March 8, 2008, when Big Sky Airlines ended operations in bankruptcy.
- Sidney-Richland Municipal Airport (SDY) has 2 runways.
- The furthest airport from Sidney-Richland Municipal Airport (SDY) is Sir Gaëtan Duval Airport (RRG), which is located 10,383 miles (16,711 kilometers) away in Rodrigues Island, Mauritius.
| Rank | Distance & Direction | Airport Name & IATA Code | Airport Location | Further Actions |
| 1 | 57.09 miles (91.88 km) WSW | Launceston Airport (LST) | Launceston, Tasmania, Australia |     |
| 2 | 77.01 miles (123.93 km) WNW | George Town Aerodrome (GEE) | George Town, Tasmania, Australia | |
| 3 | 87.36 miles (140.59 km) N | Flinders Island Airport (FLS) | Flinders Island, Tasmania, Australia | |
| 4 | 96.86 miles (155.88 km) W | Devonport Airport (DPO) | Devonport, Tasmania, Australia | |
| 5 | 110.94 miles (178.53 km) SSW | Hobart International Airport (HBA) | Hobart, Tasmania, Australia | |
| 6 | 134.69 miles (216.77 km) W | Burnie Airport (BWT) | Burnie, Tasmania, Australia | |
| 7 | 170.12 miles (273.78 km) W | Smithton Airport (SIO) | Smithton, Tasmania, Australia | |
| 8 | 241.32 miles (388.37 km) N | Bairnsdale Aerodrome (BSJ) | Bairnsdale, Victoria, Australia | |
| 9 | 251.98 miles (405.52 km) WNW | King Island Airport (KNS) | Currie, Tasmania, Australia | |
| 10 | 287.23 miles (462.24 km) NW | Moorabbin Harry Hawker Airport (MBW) | Moorabbin, Victoria, Australia | |
| 11 | 300.22 miles (483.16 km) NW | Geelong Airport (GEX) | Grovedale, Victoria, Australia | |
| 12 | 300.66 miles (483.86 km) N | Mount Hotham Airport (MHU) | Mount Hotham, Victoria, Australia | |
| 13 | 307.52 miles (494.90 km) NW | Essendon Airport (MEB) | Melbourne, Victoria, Australia | |
| 14 | 312.45 miles (502.84 km) NW | Melbourne Airport (MEL) | Melbourne, Victoria, Australia | |
| 15 | 315.73 miles (508.12 km) NW | Avalon Airport (AVV) | Avalon, Victoria, Australia | |
| Rank | Distance & Direction | Airport Name & IATA Code | Airport Location | Further Actions |
| 1 | 12,317.39 miles (19,822.86 km) NNW | Corvo Airport (CVU) | Corvo Island, Azores, Portugal | |
| 2 | 12,303.39 miles (19,800.33 km) NNW | Flores Airport (FLW) | Flores Island, Azores, Portugal | |
| 3 | 12,187.96 miles (19,614.57 km) NW | Graciosa Airport (GRW) | Graciosa Island, Azores, Portugal | |
| 4 | 12,185.49 miles (19,610.60 km) NW | Horta International Airport (HOR) | Horta, Azores, Portugal | |
| 5 | 12,177.83 miles (19,598.28 km) NW | Pico Airport (PIX) | Pico Island, Azores, Portugal | |
| 6 | 12,134.30 miles (19,528.22 km) NW | Lajes Air Base (TER) | Lajes, Azores, Portugal | |
| 7 | 12,031.26 miles (19,362.39 km) NW | João Paulo II Airport (PDL) | Ponta Delgada, Azores, Portugal | |
| 8 | 11,974.54 miles (19,271.10 km) NW | Santa Maria Airport (SMA) | Santa Maria, Portugal | |
| 9 | 11,421.39 miles (18,380.90 km) WNW | Madeira Airport (FNC) | Funchal, Madeira, Portugal | |
| 10 | 11,418.70 miles (18,376.57 km) WNW | Porto Santo Airport (PXO) | Porto Santo, Madeira, Portugal | |
| 11 | 11,317.17 miles (18,213.17 km) ENE | St. John's International Airport (YYT) | St. John's, Newfoundland and Labrador, Canada | |
| 12 | 11,258.38 miles (18,118.57 km) NW | La Palma Airport (SPC) | La Palma, Canary Islands, Spain | |
| 13 | 11,249.17 miles (18,103.75 km) W | Vigo Airport (VGO) | Vigo, Galicia, Spain | |
| 14 | 11,244.10 miles (18,095.58 km) W | Francisco Sá Carneiro Airport (OPO) | Porto, Portugal | |
| 15 | 11,241.46 miles (18,091.33 km) WNW | Santiago de Compostela Airport (SCQ) | Santiago de Compostela, Spain | |
| Rank | Distance & Direction | Airport Name & IATA Code | Airport Location | Further Actions |
| 1 | 41.33 miles (66.52 km) NE | Sloulin Field International Airport (ISN) | Williston, North Dakota, United States | |
| 2 | 48.66 miles (78.31 km) SW | Dawson Community Airport (GDV) | Glendive, Montana, United States | |
| 3 | 69.41 miles (111.70 km) WNW | L. M. Clayton Airport (OLF) | Wolf Point, Montana, United States | |
| 4 | 76.29 miles (122.77 km) NNW | Sher-Wood Airport (PWD) | Plentywood, Montana, United States | |
| 5 | 90.57 miles (145.76 km) SE | Dickinson Theodore Roosevelt Regional Airport (DIK) | Dickinson, North Dakota, United States | |
| 6 | 111.04 miles (178.70 km) SSE | Bowman Municipal Airport (BWM) | Bowman, North Dakota, United States | |
| 7 | 117.38 miles (188.91 km) WNW | Glasgow International Airport (GGW) | Glasgow, Montana, United States | |
| 8 | 118.10 miles (190.06 km) NNE | Estevan Regional Aerodrome (YEN) | Estevan, Saskatchewan, Canada | |
| 9 | 118.99 miles (191.50 km) SW | Miles City Airport (MLS) | Miles City, Montana, United States | |
| 10 | 131.42 miles (211.49 km) W | Jordan Airport (JDN) | Jordan, Montana, United States | |
| 11 | 139.74 miles (224.89 km) ENE | Minot Air Force Base (MIB) | Minot, North Dakota, United States | |
| 12 | 140.05 miles (225.38 km) ENE | Minot International Airport (MOT) | Minot, North Dakota, United States | |
| 13 | 174.07 miles (280.14 km) ESE | Bismarck Municipal Airport (BIS) | Bismarck, North Dakota, United States | |
| 14 | 189.51 miles (304.99 km) N | Regina International Airport (YQR) | Regina, Saskatchewan, Canada | |
| 15 | 191.53 miles (308.24 km) NNW | CFB Moose Jaw (YMJ) | Moose Jaw, Saskatchewan, Canada | |
| Rank | Distance & Direction | Airport Name & IATA Code | Airport Location | Further Actions |
| 1 | 10,383.49 miles (16,710.57 km) SSE | Sir Gaëtan Duval Airport (RRG) | Rodrigues Island, Mauritius | |
| 2 | 10,297.57 miles (16,572.29 km) SE | Sir Seewoosagur Ramgoolam International Airport (MRU) | Plaisance, Mauritius | |
| 3 | 10,290.39 miles (16,560.74 km) SE | Pierrefonds Airport (ZSE) | Saint-Pierre, Réunion | |
| 4 | 10,266.41 miles (16,522.14 km) SE | Roland Garros Airport (RUN) | St Denis, Réunion, France | |
| 5 | 10,218.50 miles (16,445.05 km) SE | Tôlanaro Airport (FTU) | Tôlanaro, Madagascar | |
| 6 | 10,203.17 miles (16,420.36 km) W | Margaret River Airport (MGV) | Margaret River, Western Australia, Australia | |
| 7 | 10,179.29 miles (16,381.94 km) W | Busselton Regional Airport (BQB) | Busselton, Western Australia, Australia | |
| 8 | 10,169.42 miles (16,366.06 km) W | Manjimup Airport (MJP) | Manjimup, Western Australia, Australia | |
| 9 | 10,153.64 miles (16,340.65 km) W | Bunbury Airport (BUY) | Bunbury, Western Australia, Australia | |
| 10 | 10,120.11 miles (16,286.69 km) W | Albany Airport (ALH) | Albany, Western Australia, Australia | |
| 11 | 10,113.85 miles (16,276.63 km) ESE | Ampanihy Airport (AMP) | Ampanihy, Madagascar | |
| 12 | 10,100.83 miles (16,255.67 km) WSW | Rottnest Airport (RTS) | Rottnest Island, Western Australia, Australia | |
| 13 | 10,089.33 miles (16,237.15 km) WSW | Jandakot Airport (JAD) | Jandakot, Western Australia, Australia | |
| 14 | 10,078.56 miles (16,219.83 km) WSW | Perth Airport (PER) | Perth, Western Australia, Australia | |
| 15 | 10,076.48 miles (16,216.49 km) W | Katanning Airport (KNI) | Katanning, Western Australia, Australia | |