How Does the Weather Affect How You Fly a Helicopter?

Introduction

Weather condition is an important aspect that needs to be taken into consideration while using a helicopter. No doubt, safe flying requires good weather conditions, but bad weather conditions are unpredictable and special precautions needs to be taken in order to deal with them. Although it’s very difficult to define the aspects of good weather, defining the elements of bad weather can provide greater understanding. Some of the most important features of bad weather taken into consideration while flying a helicopter are heavy fog, thunderstorms, winds, frosts, heavy snow etc. How does the weather affect how you fly a helicopter in the fog, rain, snow and other conditions? Let’s find out.

Fog, Rain, and Snow

The first and foremost thing that is required for a helicopter flight is good visibility. Heavy fog, rain, and snow are supposed to be the biggest hurdle for flying a helicopter. Even if a flight is taken during foggy conditions, its landing becomes almost impossible from a safety point of view. In such cases, there is no option other than diverting the helicopter to a base where there is minimum or no fog. Moreover, thunderstorms have also been the reason for many helicopter accidents in the past.

Turbulence

However, bad weather is not the only cause of helicopter accidents. Surprisingly, most of the accidents in the past have occurred in clear weather. Conditions like the clear air turbulence (CAT), which occurs in clear air, can’t be ascertained by helicopter’s radar. CAT generally takes place in cloudless skies and at higher altitudes when a sudden disturbance in the air is caused by small scale wind velocity gradients around the high speed air of the helicopter’s fan. The high velocity air comes in contact with much slower air, resulting in sudden air currents and turbulence around the helicopter. Though experienced and specially trained pilots can easily make out CATs through weather charts, turbulence is an evil which cannot be seen and prevented. CAT can only be felt by the bumps generated by the turbulence, making it extremely difficult to deal with.

Frosty Weather

Turbulence is not the most prevalent problem of the many effects of weather on the helicopter. The most dangerous of all the hindrances is the frosty weather. Not only is the air temperature negative, but also the humidity level in the atmosphere is high. This leads to adverse effects on the helicopter including control problems and even crashes.

Frosty weather not only affects a helicopter while flying but also when it is not in use. For this reason, the helicopter needs to be cleared of all the ice before it takes off. Generally, a very warm anti-freeze solution is sprinkled on the helicopter to restrict the forming of ice layers on and inside the helicopter parts. For additional safety, not just the helicopter but even the landing-base needs to be cleared of the snow. Initially, de-icing salt was used for this purpose; however its usage has been halted in recent year since it has been proven that it might result in corrosion or end up being sucked into the helicopter’s engine.

Direction and Speed of the Wind

The wind's direction and speed also play important roles in flying a helicopter. Headwind, the wind that flows opposite to the path of the helicopter, slams the helicopter’s nose and slows it down, whereas a tailwind push forces the helicopter in the same direction raising its speed. This is an extremely dangerous condition that has led to loss of control and accidents in the past. Just like headwind, crosswinds that blow across the path are also equally dangerous to the helicopter. Crosswinds have a tendency to fluctuate and they especially vary on the basis of the method the pilot chooses to approach the landing zone. The pilots who are aware of vectors can easily estimate whether the force of crosswind is headwind or tailwind.

Helicopter pilots need to maintain adequate vision references for helicopters under Visual Flight Rules (VFR) in order to maintain proper control, whereas helicopters under Instrument Flight Rules (IFR) are certified to be flown by instrument-related pilots without any visual references. Weather conditions for take-off and landing of this type of flight varies depending on the location, equipment, and facilities available.

When asking "How does weather affect how you fly a helicopter?" one must understand the different conditions responsible. Though aviation technology has advanced drastically, sometimes in adverse weather conditions, patience and alertness can go a long way in maintaining safe flight status, be it caused by bad.

Source: http://www.brighthub.com