Whether you are flying a small light aircraft or a large airliner, flying through a thunderstorm is something that must be avoided as it poses a great danger to the aircraft.
Even in the vicinity of a thunderstorm there are dangers so its best to give them a wide berth. You have probably noticed this when flying nearby thunderstorms, especially at night when you can see the lightning flashes in the distance.
So what are the dangers of flying in thunderstorms?
1. Turbulence. Turbulence, associated with thunderstorms, can be extremely hazardous. Bear in mind that within a thunderstorm cloud you can have columns of air rising and falling adjacent to each other at 7000 feet/minute. This has the potential to cause overstressing of the aircraft or loss of control. Thunderstorm vertical currents may be strong enough to displace an aircraft up or down vertically as much as 2000 to 6000 feet. The greatest turbulence occurs in the vicinity of adjacent rising and descending drafts. Gust loads can be severe enough to stall an aircraft flying at rough air (maneuvering) speed or to cripple it at design cruising speed.
Severe turbulence is not just present within the cloud. It can be experienced up to 20 miles from severe thunderstorms and will be greater downwind than into wind. Severe turbulence and strong out-flowing winds may also be present beneath a thunderstorm. Microbursts can be especially hazardous because of the severe wind shear associated with them.
2. Whilst lightning strikes are not uncommon and are not normally a major hazard, they can be. Static electricity may build up in the airframe, interfering with operation of the radio and affecting the behaviour of the compass. Trailing antennas should be wound in. Lightning blindness. may affect the crew’s vision for 30 to 50 seconds at a time, making instrument reading impossible during that brief period.
3. Hail. Hailstones are capable of inflicting serious damage to an aeroplane. Hail is encountered at levels between ten and thirty thousand feet.
4. Icing. Heaviest icing conditions occur above the freezing level where the water droplets are supercooled. Icing is most severe during the mature stage of the thunderstorm.
5. Pressure. Rapid changes in barometric pressure associated with the storm cause altimeter readings to become very unreliable.
6. Wind. Abrupt changes in wind speed and direction advance of a thunderstorm present a hazard during take-off and landing. Wind Gusts in excess of 80 knots have been recorded.
7. Rain. The thunderstorm contains vast amounts of liquid water droplets suspended or carried aloft by the updrafts. This water can be as damaging as hail to an aircraft penetrating the thunderstorm at high speed and can cause hazards during take off and landing.
So with all this in mind, it is clear that thunderstorms are something to be avoided at all costs.