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E6B Flight Computer Bezel (continued)
E6B Flight Computer Bezel (continued)
12 o’clock (which represents the 60 miles traveled in 1
hour). Directly below the numeral 25 on the bezel you
should see the numeral 15 on the face. The 15 represents
the significant digits of the answer and we must decide
whether there should be 0, 1 or 2 zeros after the 15. You
can probably guess how many, because 15 miles in 2 1/2
hours is obviously too little and 1500 is obviously too much.
So the answer must be 150 miles.
• Let’s try another example:
Again, you’re going down the freeway at 70 miles-per-hour.
You’ve been traveling at that speed for 110 minutes. How
far have you traveled?
• Solution:
Turn the bezel so that the numeral 60 (which represents 60
minutes) on the bezel is right above the number 7 (which
represents 70 miles-per-sixty minutes). Now find the
numeral 11 on the bezel and look directly below it on the
face. You will note that the 11 is between the numeral 12
and 13 on the face. We must now interpolate. First we must
decide whether the numerals 12 and 13 on the face
represent 12 and 13, 120 and 130, 1200 and 1300, etc.
It’s obvious that 12 is too little and 1200 is too big, but
sometimes it’s not so obvious. So here’s another method. At
70 miles-per-hour (70 miles in 60 minutes), you would have
to travel over 14 hours to go further than 1000 miles. 14
hours is 840 minutes. So the answer must have more than 2
and less than four digits. In other words, it must have 3
digits until you get above 14 hours or 900 minutes. After
using the Flight Computer for a while these mental/estimates
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will become second nature (i.e. intuitive). Now that we’ve
done the mental calculation, we know that the answer must
have 3 digits. Therefore 12 must represent the number 120
and 13 must represent the number 130. Since there are four
ticks between the 12 and 13, there are five divisions between
them. Since they represent the difference between the
numbers 120 and 130, which is 10, each tick must represent
2. Since the numeral 11 on the bezel is above the last tick
before the 13 on the face, it represents 4 ticks at 2 each,
which is 4 X 2 = 8. Therefore the distance traveled in 110
minutes at 70 miles-per-hour is 120 + 8 = 128 miles.
How to calculate distance and fuel usage
Now that you know a few of the basics, you can start using the
Flight Computer to estimate your distance or fuel usage in
relation to time. Simply select the numeral on the bezel that
represents the time interval and set the bezel so that number
is directly above the numeral on the face represents the
number of miles, kilometers, nautical miles or pounds of fuel
traveled or used in that time period. Then, as time passes, you
locate the lapsed time on the bezel and look directly below it
for the approximate distance traveled, fuel usage, etc.
How to convert basis units
The Flight Computer is provided with red arrows on the face
for converting to and from nautical miles, statute miles and
kilometers. The Red arrow above the “A” in “STAT” on the
face is for statute miles. The red arrow above the “U” in
“NAUT” on the face is for nautical miles. The red arrow above
the “H” in MPH is for kilometers. To convert, for example,