And is there such a thing as fast enough? Or is it a case of the tortoise versus the hare? Even though the aviation world is largely one of knots and not miles per hour, when it comes to speed, some of us still think in terms mph. With the advent of a number of slippery, big-engine singles, most notably the Cirrus SR22, knots might well be the new benchmark of how fast fast is.
The big question remains, though. What does speed mean in real terms? What kind of advantages do those fast movers enjoy, and is it worth what you have to pay for it?
The answers are, there are a lot of advantages, some big, some not so big, and the costs can be great. Can they be too great? Good question. Fair enough. And super long days with a trip home late in the evening almost guarantees less than optimal human performance on those last legs.
But in terms of the simple math, again with that mile trip, which is average for most pilots, how much does speed get you? Is the time worth what it costs to save it? Real-world cross-country flying is all about taking all the parameters into account, and that means looking realistically at weather, optimum altitudes, passenger needs and the amount of daylight you have to work with—winter days are short.
When you begin factoring in considerations such as required alternates on an IFR flight plan or thunderstorm diversions, the process can get complicated, and pilots need to have a solid grasp of all of the variables that go into planning any particular trip. So is the extra speed worth it? In the small picture, maybe not. But when you take a wider view of what cross-country flying is all about, the additional speed is priceless.
Within the traditional general aviation fleet, however, there are actually only a few airplanes that can honestly claim to cruise mph. The big question is how much time is extra speed actually saving you, and is it worth the additional expense and potential hassle?
The most obvious advantage is that it costs less to get into the game to begin with. But what if you desperately want the bragging rights that go with a knot cruise speed? Or what if you really do need that speed on long trips? Is there such a thing as cheap speed, and how do we evaluate it? As a general rule, airplanes can fly from to miles per hour, although this is most common with commercial planes. However, this is only an average because wind and the elements can affect that number.
In addition, military aircraft, private jets, and other types of aircraft may have speeds that are higher or lower. Big commercial airplanes generally fly in the MPH range, but their landing and taking-off speeds are naturally going to be different. As a general rule, airspeed is measured according to the velocity of the plane as it flies through the air. Wind resistance can affect that speed more than anything else, and if takeoff and landing speeds vary it is due to overall weight capacity or runway length, among other factors.
They publish these sheets for every make and model of aircraft in use today and are therefore a great way to get this type of information. If you love speed, private jets are the way to go. After measuring the distance r and location of an object x on the ground, I get:. Since this is a right triangle, I can use the Pythagorean theorem to find a relationship between the three sides:.
Remember, I don't know h and I don't know s , but I can find several values for r and x. So here's the plan: Make a plot of r 2 vs. It should be a parabolic equation. If I fit a parabola to this data, the coefficients should give me both h and s :. View Iframe URL. Technically, the coefficient in front of the x 2 term should be 1.
Instead, I will look at the coefficient in front of the x term. This should be equal to 2s and I get a fitting value of This means s should be half that value at I can use that to determine the exact location of the plane.
What about the constant term from the fit? This should be equal to h 2 such that the altitude of the plane is 3, meters. Now that I know where the plane is, I can determine how fast it is moving. All I need to do is to track the motion of an object on the ground. Of course, I am seeing the angular motion of that object and not its speedthings that are farther away appear to move more slowly this explains why the moon seems to follow you around.
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