How the distance covered by a plane was measured when GPS was not there?

Question

There are many types of speeds in case of a plane but which speed would measure the actual ground distance between two points without GPS

Answer 1

Ground speed is the actual speed over the ground. There are a number of ways of determining the ground speed of an aircraft that have been around since way before GPS existed.



If you know the winds aloft, you can determine your ground speed from your true airspeed, and you can determine your true airspeed from indicated airspeed (sometimes TAS is indicated directly in the cockpit). During the course of a flight you can infer ground speed from navigation fixes taken periodically. At one time, airline pilots determined their positions over the oceans by celestial navigation, which is why some older airliners still have "eyebrow" windows over the main windows in the cockpit.



If you have nearby VOR/DME stations, you can determine ground speed from those, too, irrespective of winds aloft. You can do it without DME, too, as long as you can determine your position over time.



Other navigation aids, such as inertial navigation systems and flight management systems on airliners, also provide ground speed, and they can do so even without GPS.



Essentially everything you can do with GPS could also be done before GPS, it just required a little more training and effort. It's all just a question of standard air navigation.

Answer 2

A chart(airplane map) and E6B flight calculator. They also had several checkpoints around the airport so the pilot would know he is on track. Many people still fly this way. You plot out the flight and keep track of the time and speed. I.e.: If you flying from Airport to Airport B which is 50 miles East, 20 miles South. You will have check points and headings. If there are 3 checkpoints you would leave Airport A and fly heading 24 until you reach check point A in which you turn heading 21 until you get to check point B then you will turn heading 26 until you reach checkpoint C then turn heading 27 until you see Airport B then you adjust as needed and land.

Answer 3

Distance doesn't change because of speed. If you mean time between two points based on speed, you can use V=D/T where Velocity = Distance divided by Time. Velocity would be ground speed, not airspeed in this case.

Answer 4

It's called ground speed, and it was calculated, not measured.

You know the distance from one check point or fix to another, so you time how long it takes to cover the distance and use your E6B to calculate ground speed.

Answer 5

Ground speed.

Answer 6

It's called "dead reckoning" and was used by Wilber & Orville Wright. Way back when, pilots actually had to look out the window, see where they were over the ground, use a map and point the airplane in the direction they wanted to go. How Crude!

Answer 7

Groundspeed. Compass and clock, that was how Lindbergh found Paris and looking out the window (pilotage) always works.

Answer 8

Celestial observations.



Charts show distances.



Distance measuring equipment (DME)