The speed restriction is there to enable a safer control of aircraft in a constricted space. Remember this is your speed through the air and not across the ground, so if the same wind you had on the runway is still blowing at this level you will have a ground speed of 230 Knots if you fly against it, but if you turn around and fly with the wind you will be doing 270 knots ground speed. At busy airports, this can be a long involved process and you may find yourself tracking all over the countryside, possibly even in the opposite direction to your intended destination.ĭuring this phase of flight, the rule of thumb all over the world is that you must remain under 250 KIAS (Knots Indicated Air Speed). You will be given an assigned altitude, compass heading and speed. Now in the climb out phase, air traffic control will be aware of the flight plan you have lodged, however, their first priority is to get you into a traffic flow that will clear you from the airport area without banging into other flight traffic. It is a little more complex than that but it gives the idea at least.Ī breakdown of the basic phases of an airliner’s flight. The higher the pressure which is driven by the forward movement of the aircraft, the higher the bladder causes the dial to read. Simplistically this is measured by air rushing into a forward facing tube called a pitot head or pitot tube which channels the air into a bladder inside the Air Speed Indicator. This is measured and expressed as KIAS or Knots Indicated Air Speed. So we have established that speed through the air is the governing factor of flight. The result is you would take the tops off the car park shuttle buses on the perimeter road which is not approved. If you decided to take-off with the wind in the other direction, you would start off with 20 knots of wind going the wrong way over your wings and therefore would require a longer take-off run. This makes for a shorter take-off run as you started with a bonus of 20 knots before you even applied engine power. For instance, if the wind is blowing in your face at 20 knots, you only need to achieve 132 knots ground speed before you can expect the aircraft to start flying. When you are taking off, you don’t care about how fast the wheels are spinning on the ground, you care about how fast the air is moving over your wings. Ok, the additional information we need is that the local wind on the runway is blowing in your face and you will take off into the wind. Hold on a minute, what does that mean exactly? We’ve done our calculations and with the weight of cargo and fuel, we expect the airliner to become airborne at, for example, 152 knots(nautical miles per hour).
Average speed of passenger plane full#
We are sitting on the runway in a shiny new Boeing 777 about to apply full power and commence our take-off run. When we ask the question, how fast is an aircraft going? There are several answers that can be given and it can be very dependent on the stage of flight the aircraft is in. The winds move slightly with the seasons but can be counted on to the extent that airlines schedule their flights taking into account a faster flight with the Jetstream and slower flight against the Jetstream.
When flying with the Jetstream, one can easily add significant speed to the flight and reduce the flying time to the destination. Since the advent of jet airliners in the 1950s which could fly much higher than their propeller ancestors, it was found there are very strong winds at those higher altitudes which were named the Jetstream. Like the early traders, we still count on the wind to aid us in reaching our destinations more quickly. These winds were counted on by the early sailing ships and were so named as they blew the early traders to and from their destinations.Īir India Boeing 787 8 climbs out on a Sydney gray day. On the surface, we know of the Trade Winds that blow along the Equatorial regions. Some winds are a constant feature of the atmosphere. The currents or winds and the changing pressure plays a huge part in the planning of flights and the way they are carried out. Also like the sea, it has varying pressures with the highest pressure being at the Earth’s surface and that pressure decreasing the further we get from the surface until we reach the near vacuum of space. The atmosphere in which you will be flying is a very fluid environment and just like the sea, has established currents. To answer this we have to look at the various factors that determine the answer. How often have you sat aboard a jet airliner and wondered about the average plane speed and how it is arrived at? Why is it that different speeds are used at different stages of the flight and why do they climb to different altitudes each time you fly?