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Ground School

CI Pesto

Topics of Discussion Today

• Time, Speed, and Distance Calculations

• Solving TVMDC Questions

• 1 in 60 Rule

• E6B Calculations of the circular side

Time, Speed, Distance

• Speed, Time and Distance are related by the equation:

Speed = Distance Time

-Given any of the two variables, the other can be found using this equation

Questions!

Speed = Distance Time

Speed = 65 KM 0.5 Hrs

*Note: Times need to be converted into

hours

Speed = 130 KM/Hr

More Questions!

Time = Distance Speed

Time = 200 Km 100 km/Hr

Time = 2 Hrs

Questions Cont.

Distance = Speed × Time

Distance = 50 Km/Hr × 3 Hrs

Distance = 150 Km

Speed Conversions

• Knots to MPH Multiply by 1.15

• MPH to Knots Divide by 1.15

• KPH to Knots Multiply by 0.54

• KPH to MPH Multiply by 0.62

Time Conversions

• Hours to Minutes Multiply by 60

• Minutes to Hours Divide by 60

Time Conversion Q’s

Hours Minutes

1 hr

270 mins

3.25 hrs

45 mins

Time in Flight

• To find the time in flight, divide the distance by the ground speed.

The time to fly 120NM at a ground speed of 80 knots is:120 ÷ 80 = 1.5 hrs (1.5 hrs × 60 = 90 mins) 1 hr and 30 mins

Distance

• To find the distance flown in a given time, multiply groundspeed by time.

The distance flown in 1 hr. 45 min. at a ground speed of 120 knots is: 120 × 1.75 = 210 NM (1hr 45min = 105 min ÷ 60 = 1.75hrs)

Ground Speed

• To find the ground speed, divide the distance flown by the time.

An airplane flies 270 NM in 3 hrs.

The ground speed is 270 ÷ 3 = 90 knots

Who RemembersTVMDC?

TVMDC

• True Heading

• Variation

• Magnetic Heading

• Deviation

• Compass Heading

Or:TV MAKES DUMB CADETS

Useful or No?

•Why?

Finding Magnetic Heading

• Use your True Heading and Variation to find your Magnetic Heading

This is important because Variation can cause a big difference between the

direction you want to go, and the direction that you actually go!

Examples

True Heading VariationMagnetic Heading

165∘ 5∘ East

280∘ 4∘ West

15∘ 8∘ West

88∘ 16∘ East

Finding Compass Heading

• Using your Magnetic Heading and Deviation to find your Compass Heading

We do this because there are errors in the compass due to manufacturing, age, friction etc. that may cause the compass to not point

exactly the way you want to go

Examples

Magnetic Heading

DeviationCompass Heading

95∘ 4∘ West

180∘ 8∘ East

360∘ 1∘ West

278∘ 12∘ East

All Together Now!

True Heading

VariationMagnetic Heading

DeviationCompass Heading

180∘ 3∘ East 4∘ West

270∘ 6∘ West 2∘ West

10∘ 5∘ East 7∘ East

145∘ 4∘ West 8∘ East

The “One in Sixty” Rule

• An error in the track of one degree will cause an error in position of about one mile in a distance of 60 miles.

Example:

3 degrees off track will cause an aircraft to be 3 miles out to the side.

The E6B (Flight Computer)

• For your Entrance Exam, you wont have to know the wind side of the E6B, only the Circular Side

• This is the side that can be used to quickly work out conversions with out the use of a calculator or paper and pen

The E6B Workings

• The outside ring is distance and velocity

• The inside ring is time

All calculations can be done without using the flight computer by using the following formula:

V = D V-velocity T D-distance T-time

The E6B Cont.

• The inner circle is made to rotate so you can line up the numbers in your equation to find the answer

• The formulas and instructions are written on the inner circle for you if you forget

E6B Cont.Velocity

• To find Velocity, you move your inner circle so that your time is under your distance. The velocity will then be indicated over the black arrow at the “60 marker”

E6B Cont.Time

• Likewise, if you are looking for time, you move the black triangle under your velocity, and find your distance on the outer circle. Your time will be on the inner circle underneath the distance

E6B Cont.Distance

• To find the distance, move the black triangle under your velocity and use your time on the inner circle to show the distance on the outer circle shown above the time.

Review

Velocity Distance Time

70 MPH 21 Mi

110 MPH 11 min

40 Mi 30 min

210 MPH 1 hr 12 min

180 MPH 30 Mi

And Thats It!Best of Luck on the

Test!~Questions~