Calculations

Question 1

Speed of Light?

Answer 1

300,000,000 m/s

Question 2

What is the speed of light in reference to radar

Answer 2

300m per microsecond

Question 3

Formula for waves

Answer 3

λ = C/f

λ = Wavelength
C = Speed of Light
F = Frequency

Question 4

Calculate the wavelength of a wave 300KHz

Answer 4

300000000/300000 = 1000m

Question 5

How to calculate the frequency of a given wavelength (Formula)

Answer 5

F = C\WL

Question 6

K M G + F

Answer 6

KILO MEGA GIGA

1000
1000^2
1000^3

Question 7

Maximum unambiguous range

Answer 7

We will use the answers in NM as the answers are in NM.
Range = speed of light/2 x PRF.
Range = 162 000 nm/2 x 1200 pps.
Thus range = 162 000 / 2400.
Range = 67.5 nm

Question 8

Formula for DME SLANT RANGE

Answer 8

D = SR S^2 - A^2

Question 9

Convert Feet to NM

Answer 9

Devide by 6076 (6000)

Question 10

PAGE RECAP

Answer 10

1352

Question 11

MAX Unambiguous Range

Answer 11

We will use the units given in the question which are km.. Maximum Range = c / 2 prf. 50 = 300 000/ 2 prf. Solving the formula, prf = 3000

Question 12

HEIGHT OF CLOUD ABOVE OR BELOW AIRCRAFT

Answer 12

HEIGHT OF CLOUD ABOVE OR BELOW AIRCRAFT (FT) = (TILT ANGLE - 1/2 BEAMWIDTH) x DISTANCE (NM) x 100 HEIGHT OF CLOUD ABOVE OR BELOW AIRCRAFT (FT) = (+4° - 2.5°) x 40 x 100

Question 13

The outer marker of an ILS with a 3° glide slope is located 4.6 NM from the threshold. Assuming a glide slope height of 50 FT above the threshold, the approximate height of an aircraft passing the outer marker is:

Answer 13

Refer to Annex for Diagram. Using Pythagorus we can find the height of the blue area. i.e. tan(3) = Height/4.6 NM. Rearranging the formula we obtain: Height = 4.6NM X tan(3) = 0.241 nm. Converting this answer to feet. i.e. 0.241 NM = 1464.8 Feet. We must then add the 50 ft above the threshold (Red Area) to obtain the aircraft’s height above the ground. Therefore 1465 + 50 = 1515 Feet

Question 14

The tilt angle of an Airborne Weather Radar (AWR) is set at +2°. If the beam width is 4° and the range of the cloud is 40 NM, what is the approximate height of the cloud above or below the aircraft when the weather return from the cloud just disappears from the screen?

Answer 14

HEIGHT OF CLOUD ABOVE OR BELOW AIRCRAFT (FT) = (TILT ANGLE - 1/2 BEAMWIDTH) x DISTANCE (NM) x 100 HEIGHT OF CLOUD ABOVE OR BELOW AIRCRAFT (FT) = (+2° - 2°) x 40 x 100

Question 15

Every 10 kt decrease in groundspeed, on a 3° ILS glide path, will require an approximate:

Answer 15

10 knots/hr = 0.167 nm/min. 0.167 nautical miles converted to feet = 1019.44 feet. Using Trigonometry: tan(3 deg) = VS/1019.44 ft. Therefore the required vertical speed is: 53.43 ft/min. The aircraft will have to DECREASE it’s rate of descent by this amount since the aircraft is travelling slower. If the aircraft was travelling faster with the constant or decreased rate of descent, the aircraft would then overshoot the runway.