Professional Pilot, May 2019

Thunderstorms I n retrospect the 2 pilots should have taken the convective sigmet calling for embedded storms more seriously The less experienced copilot was unsure but deferred to the senior pilot who argued that the sigmet covered a large area and theyd only be flying through a portion of it to get to their destination airport Deviating around the region would take too much extra time for what he felt was a pretty low risk that theyd run into any severe weather Besides they had their trusty storm scope and airborne radar to help them dodge any threats All around the aircraft billowing cumulus towers were growing and blotting out the sky above Soon they faced a wall of cloud but their radar showed only light rain and the storm scope was devoid of lightning signatures near their path They plowed on About 2 minutes into the clouds both pilots were pushed deep into their seats as a strong updraft hit them from below At the same time the storm scope began to reflect nearby flashes of lightning 72 PROFESSIONAL PILOT May 2019 Soon the aircraft stopped shaking and they emerged from the updraft 1800 feet higher than the altitude from which they had entered But before they could breathe a collective sigh of relief their left wing was hit by a massive eddy shearing from a nearby downdraft The pilots could only look on in terror as the wing separated and was briefly illuminated by a lightning stroke before it disappeared into the murk Completely out of control the copilot radioed a mayday but the forces within the storm ensured that this encounter would be fatal Investigators found most of the wreckage in a corner of a field of soybeans and concluded that the aircraft had completely disintegrated before it ever hit the ground The cause of the accident was identified as inadvertent penetration of a level 5 thunderstorm Thunderstorms Thunderstorms are a perennial topic and will continue to be because every year pilots tangle with thunderstorms and become accident file statistics Those same accident files are almost unanimous in placing the blame on pilot error for messing with a storm These pilots come from across the spectrum low and high time pilots and those flying everything from single engine piston aircraft to fly bywire commercial jets What they do have in common is that none of them meant to penetrate a storm Most of us have a healthy respect for thunderstorms But because we still want to get from point A to point B with a minimum of delay many times we think that we will be able to see and avoid the dangers of a potential storm We also may start to cut things a bit closer making the incorrect assumption that danger is inversely related to experience The complacency that comes with experience is normally what gets us into trouble with storms Convective cells Storms form all over the planet even over Antarctica Satellites and radio networks that detect lightning strokes help to paint a picture of where they are most common But even without such observation the process of formation and the properties of the atmosphere will give us a good idea of where they are most likely to be encountered WEATHER BRIEF Extreme convection remains a top threat to unprepared pilots By Karsten Shein Comm Inst Climate Scientist Lightning strikes reveal an active storm near LAS Las Vegas NV Pilots shouldnt attempt takeoffs or landings when thunderstorms are present within a mile or 2 of the runway and approach path