Commercial Ground School AVF 221

AERONAUTICAL CHARTS
For VFR, they come in 2 flavors
VFR Terminal Area Chart (TAC)
Sectional Chart

TERMINAL AREA CHART
TAC charts are for providing more detail in and around Class B
Scale is 1:250,000
1″=3.43 NM or 4 SM
Comes out every 56 days

SECTIONAL
The most commonly used chart
Scale is 1:500,000
1″=6.86 NM or 8 SM
Come out every 56 days

SYMBOLOGY

• Study your legend for the test

E6B Fast Facts:
The stationary scale is the main scale (distance)
The scale that rotates is denoting time.
The middle scale is in minutes
The inner scale is in hours

Crosswind Components
Landing rwy 18 with a wind from 210@20kts
What’s the crosswind component?
210-180=30°
CW=10
HW=17

Division
The inner black 10 is where the answers are for division
32 / 4 = 8
1. Set dividend on outer wheel (32)
2. Opposite divisor on inner wheel (4)
3. Read quotient under inner black 10 mark (8)

Multiplication
9 x 7 = 63
1. Set 9 across from black 10 (inner)
2. Find 7 on inner wheel
3. Read 63 on outer wheel
Keep in mind most problems are division/multiplication

Time, Ground Speed, Distance Problems
On all Time, Ground Speed, Distance problems the large triangular index is either set opposite Ground Speed or will position itself opposite Ground Speed.
Distance and time are always opposite each other.

Time, Ground Speed, Distance Problems
Distance 50 mi. (outer)
Ground speed 90 kts. (rate)

Time, Ground Speed, Distance Problems
Distance 450 mi. (outer)
Ground speed 140 kts. (rate)
Read Time 3 hrs. 12 min. (inner)

Fuel consumption problems
Fuel rate is read under the triangular index (usually gal/hr).
The outer scale is equivalent to the fuel used
The inner scale is flying time

Fuel consumption problems
Fuel Burn Rate 7.8 gal/hr
Time 2 hrs.
Fuel used 15.6 gal

Fuel consumption problems
Fuel Burn Rate 7.8 gal/hr
Fuel in Tanks 57.2 gal.
Total Time 7 hrs. 20 min.

Fuel consumption problems
Fuel Burn Rate 12 gal/hr
Fuel in Tanks 74 gal
Total Time 6 hrs. 10 min.

Conversion index
1. Set US gallons 9
3. Read oil weight 67.5 lbs
4. Read fuel weight 54 lbs

Feet to Meters
Set 1,100 feet
Pounds to Kilograms
Line up LBS pointer across from the KG pointer
Read mother-in-law weight in pounds of 300

Convert Nautical to Statute
1. Set NM to 52

Rate of climb
Aircraft ROC 800 ft/min
Climbing from 2000 to 14,000
How much time will it take
1. put 800 across from the black 10
2. find 12,000 on outer wheel
3. read 15 min on inner wheel

Rate of Descent
Aircraft cruise alt 9,000
15 min to descend to 1,000
1. set 15 on inner wheel across from 8,000
2. Find the inner black 10 read 534 feet per min on outer wheel

TAS & True Altitude
For TAS problems use the window directly above the directions “For True Airspeed & Density Altitude”
Remember TAS is on the right
For True Altitude problems use the window directly above the directions “For Altitude Computations”
Remember TA is on the left
So Altitude on the left Speed on the right

TAS
PA 4500
Temp. C° 10
In the right window line up 10 and 4500
Read on inner IAS 90 kts.
Read on outer TAS 97 kts.
Density altitude is 5,000

TAS
PA 10,000
Temp. C° -10
In the right window line up -10 and 10,000
Read on inner IAS 130 kts.
Read on outer TAS 150 kts.
Density altitude is 9,500

True Altitude
PA 10,000
This would be your altitude above the reporting station elevation
Temp. C° -40
Line up 10,000 across with -40 in the left window
Find indicated altitude on inner wheel
If necessary add in station elevation to this number

Density Altitude
PA 1189
Temp. C° 10
In the right window line up 10 and 1189

Density Altitude
PA 1185
Temp. C° 30
DA 3169

Mach Number
Set Mach number index across from temp
Sea level temp of -20° C
Read 630 under the inner black 10
Mach 1 occurs at 630 kts TAS

Feet per NM to Feet per Minute
Set groundspeed under the 60 pointer of 96
Find 500 feet per NM on the inner wheel

Off Course Problems
If you’ve flown 129 miles and are 8 miles off course, what’s the heading change to parallel?
Set 129 on inner wheel across from 8 on outer wheel

Off Course Problems
Let’s say we have 150 miles to go, what correction do we need to make to get back on course at our destination?
Set 150 on the inner wheel across from 8(miles off course)

Winds in Flight
Need 4 pieces of information
Ground speed 130
True course 180
True airspeed 140
Set heading index to 180 mark the difference between TH and TC (180-165=15) and TA of 140
Rotate mark straight up
Read wind direction under True Index 97°
So winds are 097@37

VOR AKT Problems
These are represented in the form of RMIs
The tail of the needle tells what the radial is
The heading is shown at the top
The frequency and the pointers at the bottom indicate either ADF or VOR
You’ll need to draw these out

Time/Distance Checks
Wing tip bearing change method
This formula uses elapsed time over a predetermined bearing change
Tune and identify
Set HI
1. determine the radial you are on
2. turn inbound and re-center the needle if necessary
3. turn 80 degrees right or left and rotate the OBS 10 degrees opposite the direction of turn
4. maintain heading when CDI centers, note the time
6. note the elapsed time when CDI again centers
7. use the formulas:

Time/Distance Checks
Isosceles Triangle Method
If the 2 angles of a triangle are equal the length of the sides are also equal
1. with the aircraft established inbound on a radial rotate the OBS 10 degrees left
2. turn 10 degrees right and note the time
3. maintain a constant heading until the CDI centers, note the elapsed time
4. time to the station is the same as the time taken to complete the 10 degree change of bearing
If ground speed is given you may also calculate distance

Rule of 60
At 60 miles 1° = 1 mile
So if you’re 10° off your 10 miles off course
At 30 miles 1 dot = 1 mile
At 30 miles 10° = 5 miles
At 15 miles 10° = 2.5 miles
Take a circle with a circumference with 360 miles
To get the radius you actually get 57.3

So 1 degree around the circle gives you 1 mile
This comes up over and over again especially with DME arcs
Rule of 60
Another way not involving mental m
ath is to use the equation
200 feet per dot per NM
So lets say your 2.5 dots off 10 NM out
200 ft x 2.5 = 500
500 x 10 NM = 5000 feet
Same deflection at 20 Nm
200 x 2.5 = 500
500 x 20 = 10,000

Obviously this would be hard to work out in the plane so the 60, 30, 15 rules of thumb work better there

HSI