Weather Hazards

Thunderstorms prove to be one of the deadliest weather hazards that can affect any pilot and any aircraft. Thunderstorms can drastically endanger the performance of an aircraft due to hazards such as wind shears, hail, low clouds, heavy precipitation, icing and lightning. A wind shear, as defined in the Pilot’s Handbook of Aeronautical Knowledge (PHAK) is a drastic and sudden change in speed and/or direction. What makes a wind shear dangerous is the rapid change it can cause to the performance of an aircraft. A tailwind can quickly change to a headwind to create an increase in airspeed and performance. The pilot must be ready to react and maintain control of the aircraft when experiencing a wind shear. Hail is the result of supercooled droplets beginning to freeze. Once a drop freezes, other drops attach and freeze to it to allow the hailstone to grow and potentially become a huge ice ball. Hail is dangerous because of the damage it can to the aircraft exterior, windows, and engine. Visibility is close to zero when within a thunderstorm cloud in addition to low clouds. Flying Visual Flight Rules (VFR) and encountering a thunderstorm leading to Instrument Flight Rules (IFR) is dangerous because the pilot may not be instrument rated and can cause spatial disorientation. Supercooled water can freeze on impact of an aircraft and can create clear ice on the wing and control surfaces can cause drag and reduce lifting capabilities. Anytime the temperature reaches 0 degrees Celsius and visible moisture is present, pilots should be on alert and ready to enable de-icing initiatives.

For a thunderstorm to take place, moisture and instability need to be present as well as lifting. Lifting is caused by the differences in air density, where warmer less dense air rises upwards to create lift. The best way to safely navigate through a thunderstorm is directly avoiding it. Thunderstorms present hazards that can adversely affect the safety and performance of any pilot of any aircraft. To avoid a thunderstorm, it is ideal to look at the weather forecast before flight and getting updates during flight. Weather briefings can be obtained through the website aviationweather.gov or a flight service station by calling (1-800-WXBRIEF)