Nonstop flight route between Sidney, Montana, United States and Den Helder, Netherlands:

About this route:

A direct, nonstop flight between Sidney-Richland Municipal Airport (SDY), Sidney, Montana, United States and De Kooy Airfield (DHR), Den Helder, Netherlands would travel a Great Circle distance of 4,334 miles (or 6,975 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 Sidney-Richland Municipal Airport and De Kooy Airfield, 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 Sidney-Richland Municipal Airport and De Kooy Airfield. You'll see that it will travel the same route of the red line on this map!

Departure Airport Information:

Arrival Airport Information:

Facts about Sidney-Richland Municipal Airport (SDY):

• Sidney-Richland Municipal Airport (SDY) has 2 runways.
• 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.
• As per the Federal Aviation Administration, this airport had 2,031 passenger boardings in calendar year 2008, 2,766 in 2009, and 3,659 in 2010.
• 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.
• Scheduled air service temporarily ceased on March 8, 2008, when Big Sky Airlines ended operations in bankruptcy.

Facts about De Kooy Airfield (DHR):

• De Kooy Airfield (DHR) currently has only 1 runway.
• The furthest airport from De Kooy Airfield (DHR) is Chatham Islands (CHT), which is located 11,805 miles (18,998 kilometers) away in Waitangi, Chatham Islands, New Zealand.
• The closest airport to De Kooy Airfield (DHR) is Amsterdam Airport Schiphol (AMS), which is located 43 miles (68 kilometers) S of DHR.
• Because of De Kooy Airfield's relatively low elevation of 4 feet, planes can take off or land at De Kooy Airfield 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.
• Most movements on the De Kooy are made by helicopters, bringing workers to and from offshore oilrigs and naval helicopters such as the Westland Lynx or NH90 of the Royal Netherlands Navy.
• The oil fields in the North Sea will eventually be depleted and when that happens the airport would lose most of its helicopter movements and thus alternative markets are being looked at, such as business and holiday flights.
• In addition to being known as "De Kooy Airfield", other names for DHR include "Vliegveld De Kooy", "Den Helder Airport" and "Maritiem Vliegkamp De Kooy".