Nov 23, 2018

Commercial Airplane FlyingIt no surprise one of the biggest factors affecting an aircraft’s movements during flight is the wind. Seeing as aircraft very rarely travel in exactly the same direction as the wind, in order for an aircraft to maintain the desired course during flight, it is necessary to continually compensate for both wind direction and wind speed.

Even though an aircraft has its own means of propulsion, the speed and direction of the wind can significantly alter an aircraft’s in-flight progress, this is often referred to as “wind effect”. Keeping an aircraft on its intended flight path through the air is therefore determined by the forward motion or thrust of the aircraft through the air and the natural movement of that air (wind).

Forces That Act On An Aeroplane In Flight

In order to understand the effects of wind on an aircraft during flight it is necessary to understand the forces acting on that aircraft as it moves through the air.

  1. Weight. The force on the aircraft directed downwards towards the earth.
  2. Lift. The opposing force needed to overcome weight. The majority of lift is generated by the aircraft’s wings utilising the forward motion of the aircraft through the air.
  3. Drag. The resistance faced when the aircraft moves through the air.
  4. Thrust. The propulsion required to overcome the drag. Thrust is created traditionally by propeller or turbine propulsion systems.

Common Types Of Wind

Airplane Flying Above CloudsWhen discussing the ‘wind effect’ it is important to understand the three broad classifications of wind types.

Headwind. A headwind is wind blowing directly towards the front of the aircraft. A headwind increases drag.

Tailwind. A tailwind is wind blowing directly towards the rear of the aircraft. A tailwind assists the aircraft’s propulsion systems.

Crosswind. Winds blowing in any other direction than a headwind or tailwind.

How Does Wind Affect Aircraft Performance?

Airplane's In FlightCan planes take off and fly in heavy winds? The three different types of winds all have different effects on an aircraft, here are 4 common questions about flying in windy conditions.

1. Why Are Headwinds Good For Takeoff And Landing?

During takeoff headwinds help to increase lift, meaning a lower ground speed and a shorter runway distance is needed for the plane to get airborne. Landing into the wind has similar advantages; less runway is needed and ground speed is lower at touchdown.

Landing in crosswinds and tailwinds make takeoff and landing more challenging and at times can mean it is not possible to attempt either. Every aircraft has set limits for takeoff and landing in a cross wind and is not permitted to operate if conditions exceed those limits.

2. Are Wind And Weather Conditions Considered Pre-Flight?

Flight planning is an important part of any flight. Every pilot takes into consideration weather conditions and winds when choosing a suitable flight path or when planning a flight.

Tailwinds are useful to travel faster and save on fuel as less power is needed to drive the aircraft in the direction it needs to go. Headwinds mean the exact opposite; more fuel is needed and the flight will take more time. A crosswind pushing to the side can cause you to drift off course, so the plane’s direction must be adjusted to keep it moving along the right path despite the wind.

3. Do Strong Winds Affect Flights?

Gusts of wind that change direction quickly and abruptly are one of the most dangerous wind conditions both in flight and on takeoff and landing. A sudden change in headwind or tailwind causing rapid changes in lift to the aircraft also known as ‘Wind Shear’ is one of the worst wind effects to experience, however pilots are trained to deal with these kinds of situations.

Difficult wind conditions can be an influencing factor in some aviation accidents, however there are almost always other risk factors involved. Pilots are well trained in controlling aircraft during windy conditions and understand the limitations of their aircraft. Each individual aircraft and different runway has its own pre-defined wind limits for both wet and dry conditions, but the pilot has the final decision on whether it is safe to takeoff or land, and fly in the existing conditions.

4. How Does The Pilot Keep Track Of The Wind Effect During Flight?

Pilots use a range of instruments to keep track of winds and atmospheric conditions while in-flight. Airspeed Indicators and other instruments are used to give the pilot the information they need in order to compensate for the changes in wind during flight.

Altimeters measure air pressure and altitude, Attitude and Heading Indicators are used to show the aircraft’s orientation and direction, and the Vertical Speed Indicator shows the rate of climb or descent.

Interested in the principles of flight and learning to fly? The team at Southern Wings offer professional flight training for both New Zealand and international students from their two handy locations in Auckland and Invercargill.

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