Page 9 - April 20 TNT
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 Weather categories. forecasts you heard before takeoff. If you're told St. Louis is expected to be clear all morning, for example, only to find its 2,000 broken when you actu- ally fly over, you know to suspect the forecast of VFR for your destination farther down the road. Let's say marginal weather condi- tions exist for a portion of your flight, your route is entirely away from moun- tains, and you'll easily complete your trip during daylight hours. How can you minimize risks and avoid becom- ing a scud-running statistic? 1. Know what MVFR looks like. Most f light instruction takes place in excellent weather. Even instrument training is usually conducted in good Visual Meteorological Conditions (VMC). When weather is marginal, in- strument pilot training is usually done on instrument routes and instrument f light plans. That makes sense, given the IFR training mission. No wonder then that the MVFR accident record is abysmal. Almost no one trains for it before actually trying it alone. The next time the cloud ceiling hov- ers around 1,500 feet, or the visibility is about five miles (preferably not both the first time), hire an instructor for a short round-robin training f light under Visual Flight Rules (VFR), including landing on at least one airport other than your home base. Your instructor should be extremely familiar with the local area's obstructions and naviga- tion features, as well as your make and model of airplane. He or she will serve as an extra set of hands and eyes in the cockpit should you need any help. Even your home airport will look different from low altitude or in mar- ginal weather; you'll be amazed at the increase in workload and anxiety brought on by a loss of normal visual cues and gain a healthy respect for the risks of MVFR flight. I bet if you knew ahead of time you were going to fly this exercise that you would spend a lot of time looking at the charts and pinpointing obstacles, finding land- marks you can use along the way, and thinking about how you would find the airport and enter its pattern. This is the way you should always approach flight at altitudes or in visibility less than normal for you. 2. Know where you're going. Safe f light in marginal conditions demands thorough pref light planning. You need to determine what route you'll use, and where you'll go if your primary route is closed off by weather. GPS is a wonderful thing. The pro- liferation of moving map displays and apps greatly increases a pilot’s orienta- tion. In the context of low-altitude, low- visibility f light, however, GPS may be more limited than you’d think. Some models have minimum safe altitude or minimum en route altitude informa- tion, but they use the standard FAA cri- teria of 1,000 feet above terrain (2,000 feet in mountainous areas), which may be higher than you're flying in marginal conditions. Unless you keep your GPS database updated, it may not warn of new obstacles along your route. To safely fly MVFR, you need to combine information from GPS and sectional charts (paper or electronic) and plan your route over and around terrain and obstructions. Follow high- ways and other prominent landmarks to crosscheck the moving map. Keep- ing to the right of roads, you'll be better able to see your landmark out the left side of the airplane (and you'll avoid the other MVFR pilot coming from the opposite direction). Fly from airport to airport, making a new go/no-go decision each time you pass another runway. Review landmarks near your destination so you can find it in the murk. Even with GPS it may not be as easy to find as you think. 3. Define and fly minimum altitudes. Plot the minimum safe altitude for each segment of your planned f light. At a bare minimum 14 CFR 91.199 (or equivalent in non-U.S. airspace) ap- plies: for fixed-wing aircraft, at least 500 feet above the ground, obstacle or individual at any point except over open water or sparsely populated ar- eas, and at least 1000 feet above the highest obstacle within 2000 feet laterally over congested areas. Heli- copters may f ly lower, provided the pilot complies with FAA-prescribed routes and altitudes. Crosscheck these altitudes against the VFR visibility and cloud clearance requirements of the airspace in which you’ll fly, and you can derive specific minimum (and perhaps maximum) altitudes for each segment of your f light. Chances are you’ll have a series of altitudes that changes as you progress toward your planned destination. 4. Slow down. There may be a reason retract- able gear and multi-engine airplanes are involved in more scud-running accidents than their proportion in the general aviation f leet. The faster you're flying, the harder it's going to be to avoid obstacles in low-visibility f light. In his collision-avoidance book, “See and Avoid,” Fred Delacerda quantifies the process of detecting and avoiding obstacles: "It takes the average human about 10 seconds to visually acquire a conflict, recognize it as a threat, decide to take evasive action, and make a  April 2020 / TWIN & TURBINE • 7 


































































































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