Nonstop flight route between St Athan, Wales, United Kingdom and Sidney, Montana, United States:
Departure Airport:

Arrival Airport:

Distance from DGX to SDY:
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- About this route
- DGX Airport Information
- SDY Airport Information
- Facts about DGX
- Facts about SDY
- Map of Nearest Airports to DGX
- List of Nearest Airports to DGX
- Map of Furthest Airports from DGX
- List of Furthest Airports from DGX
- 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 MoD St Athan (DGX), St Athan, Wales, United Kingdom and Sidney-Richland Municipal Airport (SDY), Sidney, Montana, United States would travel a Great Circle distance of 4,147 miles (or 6,673 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 MoD St Athan 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 MoD St Athan 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: | DGX / EGDX |
Airport Name: | MoD St Athan |
Location: | St Athan, Wales, United Kingdom |
GPS Coordinates: | 51°24'16"N by 3°26'8"W |
Operator/Owner: | Ministry of Defence |
Airport Type: | Military |
Elevation: | 163 feet (50 meters) |
# of Runways: | 1 |
View all routes: | Routes from DGX |
More Information: | DGX 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 MoD St Athan (DGX):
- MoD St Athan (DGX) currently has only 1 runway.
- On 26 August 1993 an ATC civilian instructor was seriously injured and the RAF Volunteer Reserve pilot, Group Captain Roger Sweatman, was killed when their Chipmunk trainer, on an air experience flight, crashed after encountering difficulties during a simulated emergency low-height manoeuvre on take-off.
- The last aircraft to be serviced at St Athan, a Vickers VC10, departed the site on 23 February 2012.
- The furthest airport from MoD St Athan (DGX) is Dunedin International Airport (DUD), which is located 11,960 miles (19,248 kilometers) away in Dunedin, Otago, New Zealand.
- The station officially opened as RAF St Athan on 1 September 1938 and the first unit to take up residence was No 4 School of Technical Training.
- In 2006, the Special Forces Support Group was raised at St Athan and the Welsh Guards returned to London.
- The closest airport to MoD St Athan (DGX) is Cardiff Airport (CWL), which is located only 4 miles (6 kilometers) E of DGX.
- In March 2004, however, DARA announced the loss of 550 jobs at St Athan as part of streamlining to make DARA more efficient and better able to compete with the private sector for lucrative aircraft repair contracts, but also because they lost out to a direct RAF bid for a contract to upgrade the air force's fleet of ageing Harrier jump jet aircraft.
- Because of MoD St Athan's relatively low elevation of 163 feet, planes can take off or land at MoD St Athan 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.
Facts about Sidney-Richland Municipal Airport (SDY):
- 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.
- 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.
- Sidney-Richland Municipal Airport (SDY) has 2 runways.
- Sidney-Richland Municipal Airport covers an area of 335 acres at an elevation of 1,985 feet above mean sea level.