INCREDIBLE IMAGES OF VAPOUR TRAILS AND CONES CREATED BY PLANES IN THE SKY

Holy smoke: Incredible images of vapour trails and cones created by planes in the sky
By James Titcomb, Daily Mail, 26 May 2012.

These pictures of plumes of air billowing from the back ends of aircraft may seem like a cause for concern, especially when they are a bright red in colour.

But these images actually show spinning vapour trails created by cold air circulating around the wing.

As the number of planes in the sky increases, these vapours have become an increasingly common sight, resulting in some of these incredible images of plane trails.

Red arrow: Coloured smoke was added to the plume as this plane landed as part of a NASA test to measure the effect of vortices on the air behind aircraft.

Speed of sound: This 'vapour cone' is created by a plane at high speed, and can often be seen when planes approach the sound barrier.

Parting the sky: As planes fly through clouds, the air pressure splits the cloud, as shown by this Boeing 767, taken above Gatwick airport.

Bursting through: When a plane creates a hole in a cloud, the sunlight shining through can create some spectacular effects.

Areas of low pressure form around the edge of the wing, creating vortices - tubes of circulating air - that leave trails behind the wing's tips.

The low pressure in these areas mean that cold air can condense, leaving spectacular trails of water or even ice behind the plane.

When a plane passes through a cloud, water vapour and ice from the clouds are sucked into the vortices, adding to the effect.

The air pressure created around the plane can also cut through a cloud, parting the vapours and leaving spectacular patterns behind as the clouds gather around the vortices.

Dusk: The vortices that are formed by the aircraft can come off in erratic patterns, shown by the light hitting the trails at sunset.

The vapour cone is created as a plane hits high speeds.

Red sky: This plane passing through the top of a cloud produces a spectacular wave effect.

Plumage: The ice and water picked up when a plane passes through a cloud can become part of the vapour trail.

The turbulence created by the vortices mean that the flights of any aircraft flying behind the plane are distorted, which is why planes are not allowed to land in close proximity.

Geese take advantage of the same effect when they fly in their recognisable V formation and reduce drag.

A plane breaking the sound barrier produces a similar condensation effect around an aircraft, caused by an area of low pressure rapidly forming towards the plane's tail.

The cloud vapours spin around the vortex trail left by the plane, creating this twister effect behind it.

The vapours can stay in the air for some time, creating a trail mapping the plane's flight through the air.

The vortices are created by low-pressure air spinning around behind the wing, as shown by the visible circles in this shot.

The plumes combined with natural light can produce some spectacular effects (left). The image on the right

shows the effect of a sonic boom from below the aircraft.

Geese take advantage of the same drag effect when they fly in their recognisable V formation and reduce drag.

Top image: Turbulence created by the massive change in air pressure can affect aircraft flying behind planes, meaning they cannot land too close to each other.

[Source: Daily Mail. Edited.]