Trivia Testers : The Windiest City

Question: Which US city has the highest average annual wind speed?

1. Amarillo, Texas
2. Dodge City, Kansas
3. Chicago, Illinois
4. Rochester, Minnesota
5. Boston, Mass (‘Beantown’)

Answer: It’s not Chicago, which although it claims the popular title of ‘The Windy City’ actually has an overall average annual wind speed of about nine knots. In fact, getting out of Dodge is even easier (assuming the runway is favorably aligned with the prevailing winds) because the average winds in Dodge City Kansas are a bit over 12 knots. I just couldn’t resist adding choice E. Sorry…

Question: Based on the latest AOPA eDirectory, what is the average length of public use runways in the United States? The answer is rounded to the nearest foot, but this does not include heliports, almost 14,000 privately owned airports, and some international airports (but it does include seaplane bases).

1. Due to numerous ultralight landing areas, it’s only 2484 feet.
2. There are a great number of private (but still public use) strips which are fairly short, and the average length is only 3240 feet.
3. The average runway length in the US is 4289 feet.
4. Because of the growing number of international airports, it’s 5279 feet.

Answer: C. There are 7,484 public use runways in the US (14,968 if you count both directions), and 232 public-use helipads. 213 of those 7400+ runways are on bodies of water (at sea plane bases), and 23 runways are listed as ‘all ways’ with no particular heading (including one rectangular landing surface listed as ‘balloon’). If you’re interested in just what the distribution of public-use US runway lengths looks like, it looks like this:

• As far as their lengths go, only 27 (less than half a percent) are 1000 feet or less

• 467 (about six and a third percent) are greater than 1000 feet, up to and including 2000 feet

• 1788 (about 24%) are greater than 2000 feet, up to and including 3000 feet

• 1879 (just over one-fourth) are greater than 3000 feet, up to and including 4000 feet

• 1338 (about 18%) are greater than 4000 feet, up to and including 5000 feet

• 874 (about 12%) are greater than 5000 feet, up to and including 6000 feet

• 403 (about 5.5%) are greater than 6000 feet, up to and including 7000 feet

• 232 (just over three%) are greater than 7000 feet, up to and including 8000 feet

• 152 (2.0%) are greater than 8000 feet, up to and including 9000 feet

• 150 (2.0%) are greater than 9000 feet, up to and including 10000 feet

• 61 (about 1%) are greater than 10000 feet, up to and including 11000 feet

• 49 (less than one percent) are greater than 11000 feet, up to and including 12000 feet

• 21 (less than one-half percent) are greater than 12000 feet, up to and including 13000 feet

• 11 (0.1%) are greater than 13000 feet, up to and including 14000 feet

• 24 (less than one-half percent) are greater than 14000 feet, up to and including 15000 feet…

and just eight (0.1%) are over 15,000 feet long.

Significant numbers of the very longest runways are dry lake beds. One might easily notice from these numbers incidentally that very close to half of the nation’s public-use runways are between two and four thousand feet long.

Subject: A Different Slant on Hand-held Nav/Coms

Question: Why might you want to pay particular attention to the orientation of the antenna of your hand-held nav/com?

1. Holding it at a 45 degree angle from the vertical when inside an airplane’s cockpit minimizes signal attenuation, due to interference from the fuselage.
2. Always point the antenna towards the windshield to maximize exposure to the more radio-friendly (and less radiation-blocking) plexiglass. This maximizes transmission power and effective range.
3. Simple: We need our eyes in the cockpit, and waving pointy sticks around in a confined space is just a safety hazard! Remember what your mother said!
4. Communication antennas are vertically polarized (or more strictly speaking, oriented), whereas navigation antennas are horizontally polarized (oriented). What this means in plain English is: hold it up-and-down when you’re talking, but sideways when you want to navigate using a VOR.

Answer: D. This also means (aside from the fact that you’d have to tilt your head at an awkward angle to do this) don’t expect much navigation performance if you hook up your hand-held to the aircraft’s external com antenna!