While stability and instability dont 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 FAAs Aviation Meteorology circular. For meteorologists, a chart known as the Skew-T diagram is used every day at forecast centers. Its literally a worksheet that helps forecasters visualize the days stability and make calculations on it.
These early pilots depended on a network of rotating beacon towers at four-mile intervals, like lighthouses in the sky. These facilities, operated by the federal government, used lamps powered by cylinders of acetylene. Simply by following the route from beacon to beacon, a pilot could arrive safely at the destination. Weather could be avoided because the planes flew at low altitudes, and illuminated diversion airfields were placed at frequent intervals. If the pilot felt things were deteriorating, he could be on the ground in less than 10 minutes.
The ASOS system was developed in the late 1980s to relieve the expense of maintaining human observers at hundreds of sites, improve consistency of observations, and bring high-quality observations to rural and remote airports. Much like NEXRAD it was a joint product of the FAA, NWS, and DoD, and was fielded at 1000 US airports between 1991 and 2004. Its main components are temperature, dewpoint, and wind sensors, along with new technology like sky condition, present weather, and visibility sensors.
Another good rule of thumb is Buys Bullots law: To locate where the bad weather is coming from, put your back to the wind and extend your left arm straight out. Thats where the low pressure bad WX is coming from. It works for me.
Yep, its time to make fun of those who in 2015 ignored sound judgment and lived to garner pilot lounge derision. And, since pilots tend to repeat the same mistakes in hopes of different results, we heed George Orwell who said, We have now sunk to a depth at which the restatement of the obvious is the first duty of intelligent men. Since no intelligent man or woman stepped forward, its up to me.
Unless youre under age 30 or live in a remote village in Mongolia, youve likely heard the 1971 Don McLean song American Pie, in which the events on the night of February 2-3, 1959 are recalled. That night, three of Americas top rock musicians died in a tragic aviation accident in Iowa. The accident is ingrained in American culture. I cant think of a better example of an accident worth researching for lessons to learn.
There are rules about flight into known or forecast icing conditions for Part 135 and 121 operators, but there is nothing in Volume 14 of the Code of Federal Regulations (commonly called the Federal Aviation Regulations) specifically prohibiting Part 91 flight into known icing. Instead, we look to 91.9(a). This prohibits us from operating an aircraft contrary to its published operating limitations. Add a dose of careless and reckless conduct from 91.13, and you have a better picture of the regulatory background.
Like many of you, I also ride motorcycles. I have two Hondas, one of which is 25 years old but still suits me quite well. Due to a confluence of some logistical and health challenges, now past, I hadnt ridden in a few years. Late this past summer I again undertook two-wheeled transportation.
When a Lion Air Boeing 737 Max 8 with only 800 hours crashed into the ocean in November, killing all 189 on board, the event raised a lot of questions. It behaved erratically in flight before the crew lost control, and several crews had reported problems with the airplane in the days before.
Be aware of the distinction between MSL and AGL. Cloud heights associated with airports are customarily given in AGL. But areal guidance products, area forecasts, and PIREPs, use MSL. Also, anything stated as a ceiling or carrying the CIG abbreviation is AGL. Since IFR and MVFR conditions are based upon ceiling height, centralized products will always use AGL ceilings when constructing an IFR/MVFR depiction. If there is any doubt, find the information ahead of time or talk to a briefer.
A few days ago, departing Minot North Dakota for Duluth in a Skylane, I asked ATC if the NOTAM for military training at Duluth had the airport closed, or whether it was open to GA traffic. He asked me to stand by for a minute, and then said, Its closed at the moment, but will reopen in 30 minutes, so unless you are doing Mach 3, you should have no problem.
Another day, same drill, but the controller is talking to another airplane on another frequency, so you might hear say again more than once. ATC is often tasked to use multiple frequencies at once. Its not the easiest thing to do with people talking on both, but we adapt and prioritize. One way we adapt to prioritizing is by the airplanes speed. The faster they are going, the more likely it is that I need to get to them first before they enter another controllers airspace without coordination.