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It was pretty good flying weather this past week. The welcome rain was gentle, with only a little convective activity attached. The main deterrent to taking to the skies was the wind. A strong low-pressure area to our west and then north brought the winds right across the runway, exceeding the crosswind limit for most pilots.
Now that we are back on standard time those flying late in the afternoon can enjoy a sunset. And this past week you got a lot for your money. Several of the sunsets were spectacular. And as the sun slid behind the western horizon, the moon was rising in the east. The full moon was November 10. So earlier in the week the moon was in the waxing gibbous phase. We are now in the waning gibbous phase. Gibbous means humped, which is a description of the illuminated portion of the moon.
In military aviation a bright moon is often called a “field grade” moon. It is a derisive term, meaning the moon is making enough light that field grade officers can safely get their night flying minimums.
As the days get shorter, pilots must brush up on their night flying techniques. During the long days of summer you really have to stay up late to get any serious night flying. But now, if you plan on flying after work, you are going to be up after dark.
I like to fly at night, if the weather is good. The air is usually smooth. In the summer it is certainly cooler. And the countryside takes on a new identity. Thanks to those obnoxious pole lights that nearly every rural house has, there are pinpoints of light everywhere. Even the smallest village is easy to spot, especially if it has a Casey’s store.
A bright moon does not always help low-level navigation at night. If you are flying into the moon, terrain features do not show up as well. The best scenario is to have the moon behind you, shining over your shoulder. At least that is what works best for me.
Lakes, ponds and rivers, are highly reflective, if there is some amount of celestial lighting. They make great landmarks. You would be surprised how well the gravestones in cemeteries show up on a bright night. This time of year, after the crops are out of the fields, it is easy to tell what kind of terrain you are flying over, even on a moonless night. Pastures will appear darker than a harvested corn or bean field.
It was pretty good flying weather this past week. The welcome rain was gentle, with only a little convective activity attached. The main deterrent to taking to the skies was the wind. A strong low-pressure area to our west and then north brought the winds right across the runway, exceeding the crosswind limit for most pilots.
Now that we are back on standard time those flying late in the afternoon can enjoy a sunset. And this past week you got a lot for your money. Several of the sunsets were spectacular. And as the sun slid behind the western horizon, the moon was rising in the east. The full moon was November 10. So earlier in the week the moon was in the waxing gibbous phase. We are now in the waning gibbous phase. Gibbous means humped, which is a description of the illuminated portion of the moon.
In military aviation a bright moon is often called a “field grade” moon. It is a derisive term, meaning the moon is making enough light that field grade officers can safely get their night flying minimums.
As the days get shorter, pilots must brush up on their night flying techniques. During the long days of summer you really have to stay up late to get any serious night flying. But now, if you plan on flying after work, you are going to be up after dark.
I like to fly at night, if the weather is good. The air is usually smooth. In the summer it is certainly cooler. And the countryside takes on a new identity. Thanks to those obnoxious pole lights that nearly every rural house has, there are pinpoints of light everywhere. Even the smallest village is easy to spot, especially if it has a Casey’s store.
A bright moon does not always help low-level navigation at night. If you are flying into the moon, terrain features do not show up as well. The best scenario is to have the moon behind you, shining over your shoulder. At least that is what works best for me.
Lakes, ponds and rivers, are highly reflective, if there is some amount of celestial lighting. They make great landmarks. You would be surprised how well the gravestones in cemeteries show up on a bright night. This time of year, after the crops are out of the fields, it is easy to tell what kind of terrain you are flying over, even on a moonless night. Pastures will appear darker than a harvested corn or bean field.
With a good moon, Sycamore trees with their white trunks are really easy to see.
These trees usually grow along a stream or low-lying areas. The tops of ridges seem to have more Cedar trees. Even on a moonless, summer night the coniferous trees stand out from the trees with leaves. They have a different hue, or density to them.
Pilots do not do much navigation by terrain anymore. GPS is a wonderful tool and allows us to fly cross-country without ever unfolding a map. A screen on the GPS unit depicts our airplane flying along its chosen route. Terrain features such as rivers, towns, roads and obstacles are also depicted. The GPS tells us how fast we are going over the ground and when we will be at our destination. What is not to like?
One problem with our reliance on the magic of GPS is that our basic navigation skills atrophy. It is not only a challenge, but also fun, to take a low-level night flight relying on a paper map and your own navigation skills. And having those skills burnished might come in handy some night when your airplane’s alternator fails and there is no electricity to power the GPS.
That is the joy of flying. There is always more to learn. And there are always old skills that need polishing.
We have not had a trivia question for a while, so let’s try this one: There is sunset and there is astronomical, nautical and civil twilight. What is the definition of these different kinds of twilight?
