In aerospace Engineering lightning can be seen as some what of an unavoidable and unpredictable occurrence, which takes place more often than the average aircraft passenger is aware of. No need for panic though, it is not as catastrophic as seems, one of the very few fatal occurrence in aviation caused by lightning was in 1967 when the fuel tank of a commercial aircraft was struck by a lightning bolt. Ever since then modifications have been instructed to be carried out by governing aviation bodies to shield fuel tanks from such disasters.
Modern day lightning effects can at most ground the aircraft for a short period or cause delays in aircraft services which could cost airline services. No immediate effect can be observed on board the aircraft except slight glitches on some electrical instruments noticed only by the pilots at most. Proper aerospace engineering also makes sure no entry from lightning to important electrical circuits.
when lightning hits an aircraft, it attaches itself to the aircraft through an entry point usually the radome(nose) or through the wing tips, as the aircraft flies through the strike, the high voltage current flows through the outer skin of the airplane and discharges through an exit point usually at the tail. Injuries on the aircraft body resulting from the strike can occur especially on the entry or exit points.
Storm clouds are the main generators of lightning bolts which are more rampant between 5000ft – 15000ft, which can indicates that ascending and descending times are the most vulnerable a plane can be struck. Short distance commercial aircrafts that do not operate at very high altitudes also stand a higher chance of getting struck by lightning more than the conventional cross continental aircrafts since they generally operate at higher altitudes.
Rigorous measures are always put in place in aerospace engineering to ensure continuous safety of air travel and as such over the years governing aerospace bodies ( NASA, FAA and co) have issued guidelines to manufacturers for protecting airplanes from lightning strikes.
Most aircraft’s skins are made of metal mostly aluminum which on its own is a good conductor. This allows the safe flow of current form the strike entry point (nose or wing tip) to the exit point(tail). Although a good conductor, the aluminum skin must have a high level of thickness considering the fact that voltage of a strike can be more than 30,000 amps. The thickness of the material ensures that the internal of the aircraft is not affected by the strike.
Aircraft’s composed of composites materials go through processes to ensure sufficient lightning protection, which could include laying the material with copper sheets. Components that are sensitive to sparks like the fuel tank and its surrounding components must be able to withstand high level of burning to avoid any form of explosion. Sufficient protection reduces chance of the aircraft getting injuries when struck.
Another concept for suppressing effects of lightning strike is with the use of discharge wicks. Discharge wicks basically discharge all form of electrical charges from the skin of the aircraft into the air or to the ground at touch down. They can be found at trailing edges of the wings, aileron and landing gears on aircrafts.
So with proper aerospace engineering the effect of lightning can be contained to a level that it doesn’t cause for alarm with air travelers.
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