for instructors

How to Convert Knots to MPH, and More Unit Magic
using conversion factors to change units and confirm results

The boring way to convert knots to mph is to multiply knots by 1.15.[1] But this skips over some awesome unit magic.

Specifically, we can use conversion factors to change between related units. Let’s look again at how to convert knots to mph.

Suppose you’re traveling at v\ \text{knots}=v\ \frac{\text{nautical miles}}{\text{hour}}. Then,

    \[ v\ \frac{\cancel{\text{nautical miles}}}{\text{hour}} * \frac{1.15\ \text{miles}}{1\ \cancel{\text{nautical miles}}} = v * 1.15\ \frac{\text{miles}}{\text{hour}}} = v * 1.15\ \text{mph} \]

Did You Just Cross Out the Units?

I did! This is called a conversion factor,[2] and is based on the principle that anything multiplied by 1 equals itself. It is an easy way to convert between units, and allows us to solve a variety of aviation problems.

  1. This is actually more like 1.150779, but we’ll use the rounded version.
  2. More precisely, you may hear this called dimensional analysis or the factor-label method.

10 Important Figures on the Instrument Knowledge Test
info about figures that are likely to appear and may be easy points

It turns out there is only a handful of figures on the instrument knowledge test that:

  1. Are likely to be asked about, and
  2. Could be easy points on the test.

These are the 10 figures I believe are worth a closer study.

How to Improve ForeFlight With a Bay Area Content Pack
an overview of content packs and a download for the Bay Area

If you’re planning to fly in the San Francisco area, you should install a Bay Area content pack for ForeFlight.[1]

  1. This is short post; if you already know what content packs are, this link may be all you need.

Learn ForeFlight the Easy Way: With a Flight Simulator
a collection of simulator resources to build proficiency with ForeFlight

The best time to learn ForeFlight is on the ground. With a bit of practice, you can safely leverage its many features while flying. (And avoid figuring them out in the air!)

This post collects together several resources on how to connect and use ForeFlight with a flight simulator.