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While stability and instability don’t always cause weather, they leave a mark on even VFR forecasts in many subtle ways, and they influence everything from wind gusts to cloud layers. Even in forecast models, there are always complex equations that factor in stability. Stability is important enough that an entire chapter is dedicated to it in the FAA’s Aviation Meteorology circular. For meteorologists, a chart known as the Skew-T diagram is used every day at forecast centers. It’s literally a worksheet that helps forecasters visualize the day’s stability and make calculations on it.
For those unfamiliar, the Upper Peninsula of Michigan boasts generous lengths of shoreline off Lake Superior, scenic byways, and lots of trees. While it can be a winter wonderland during the off-season, it’s not unusual to have many days of dreary gray skies and fog that wears away the most sanguine spirit. It’s the kind of weather that gets us burning through a whole morning figuring out how to get out, around and back without getting stuck who-knows-where. Welcome to the UP.
Likely you either practice approaches to non-towered airports or fly into airfields with part-time control towers. Non-towered airports, hotbeds of GA activities, present our greatest risk of a midair collision; a risk mitigated by a “disciplined adherence to procedures (proper entry into landing patterns, proper departure patterns) and proper use of the UNICOM frequency at uncontrolled airports.” (FAA Aviation News, May/June 2001) Therefore, it’s important that instrument pilots play nice around the pattern. The updated AC 90-66 covering non-towered airports specifically identifies instrument pilots, maybe because of some past misbehavior.
The answer given in question 2 of the quiz in your November 2018 issue (continue to fly straight through the storm) is incorrect. Fifty years ago I wrote and published the initial research papers on transmitting weather information into the cockpit after almost losing my life due to a thunderstorm. As a nationally recognized aviation radar/weather spokesperson, I continue to educate and update pilots around the country as the program progresses. The history of the Datalink program is best presented by AOPA’s video on YouTube. Search for “datalink concept to cockpit.”
About 30 minutes into these touch and goes, one requested a “stop and go.” I could not have five aircraft doing touch and goes with one doing a stop and go; it would mess up the pattern and I’d be making student pilots do a lot they didn’t need to. So, I come back with, “Unable. I have five of y’all.” He came back with, “Well we need to do stop and goes for training.” I thought about putting that one airplane on the other runway, but I had started to have a line of departures and arrivals. “Unable,” I repeated. I thought the matter was closed, as it should have been.
ATC will often ask pilots if they can do something somewhat out of the ordinary for the purpose of granting a shortcut or maybe to gain that extra slice of airspace. This subtle word works on both sides of the coin. In the pattern, Tower might ask a pilot to fly a short approach that—if the pilot is unprepared and accepts it—requires a steep and fast dive. Perhaps you’ve been offered that so they can fit you inside of other traffic, to avoid vectoring you 10 miles out to get behind everyone. Or, perhaps they just need you to cross the approach end of the runway so they can start getting other airplanes out. Regardless, if you don’t think you can safely and properly comply, bring on the PIC authority and just say it, “Unable.”