Tuesday, October 6, 2009
Top Mistakes In Convective Environments
How to stay safe in bad weather
Deep, moist convection, better known as thunderstorms, are the nemesis of all aircraft, big or small. Avoidance is mandatory. Many pilots, however, continue to find themselves tangled up in these giants, and very few live to tell about it. What mistakes are these pilots making to put themselves at risk?
Education Is The First Step
There’s no question that weather impacts our flying activity more than any other single physical factor. Ironically, many aviators (even seasoned pilots) will freely admit that weather is their weakest link. A majority of newly certificated pilots possess a dearth of practical skills necessary to minimize their exposure to adverse weather. Moreover, they fail to advance their weather knowledge beyond what little they were required to learn during their private and/or instrument training.
The blame shouldn’t rest entirely on the pilot. Much of what a pilot has been taught about thunderstorms probably is worthless. A good deal of this is laced with misconceptions and, in some cases, outright nonsense. Terms like “pop-up” or “air-mass” thunderstorms are a perfect example of bad information leading pilots to believe that thunderstorms just develop randomly within a stagnant environment. Senior research meteorologist Dr. Charles Doswell III suggests that even without an important change of air mass, thunderstorms develop at a particular time and place for a reason—although it’s often difficult (and sometimes impossible) to diagnose those reasons.
Flying with an instrument student back into West Houston, our route took us directly through the center of a cell east of Houston’s Hobby Airport. This thunderstorm was moving north, and we requested a deviation around the south side (upwind) of the cell, where the air was glassy smooth.
Characterize That Convection
Whether you’re taking a very short trip or one that may last several hours, knowing how to “read” the environment before you depart is paramount. Pilots always are taught that flying in the morning is the best option. This is generally true, but on any given morning, it’s possible for there to be ongoing convection associated with a severe mesoscale convective system (MCS). Even when the radar image is quiet in the morning, if your flight takes you into the early afternoon hours, you’ll definitely want to paint a mental picture of what that environment might look like.
Many pilots fail to take the time to accurately describe the convective environment they may face before they depart. It requires a great deal more than just knowing there are thunderstorms in the immediate forecast somewhere along your route. Characterizing the convection and developing a sense of what’s forecast to occur will help you stay two steps ahead of it. Will it be mostly a scattered or isolated pulse-type (i.e., air-mass) area of thunderstorms? If so, will this area likely reach convective SIGMET criteria? Is the environment conducive to microbursts? Will the MCS that developed overnight persist through the morning, or will it dissipate before you depart? Will a solid line of convection form ahead of the cold front? When and where will the onset of that prefrontal convection be located? What will the direction and speed of movement be once these storms develop? Will they be severe?
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Labels: Accident Statistics, FAA Regulations, In-Flight Emergencies, NTSB Reports, People and Places, Safety, Weather Flying, Weather Skills