WEATHER RADAR (COLLINS WXR-2100)

Question 1

Which part of a Thunderstorm is the most reflective part?

Answer 1

The lower part below the freezing level, above it ice crystals starts to form which are less reflective

Question 2

How far out, in NM can the Collins WXR-2100 scan?

Answer 2

320 NM

Question 3

320 NM ahead of an aircraft, how much of an altitude drop (in ft) does the earths curvature cause?

Answer 3

65000 ft

Question 4

How often is the WX Radar image updated on the Collins WXR-2100?

Answer 4

Every 4 seconds

Question 5

How does the MCS (Multi Scan System) work on the Collins WXR-2100?

Answer 5

Upper beam detects intermediate weather
Lower beam detects short range and long range weather due to curvature of the earth

Question 6

What is GCS on the Collins WXR-2100?

Answer 6

Ground Clutter Supression

Question 7

Can the pilots have different gain and tilt settings on their respective ND:s?

Answer 7

No, its single function

Question 8

How is the tilt value displayed on the WX radar calculated?

Answer 8

It is the average of the upper and lower beam
Split is higher at lower levels and split decreases as altitude increases

Question 9

Is tilt operation available during multi scan operation?

Answer 9

No, it is the average of the lower and upper beam
Tilt is only available in MAN mode

Question 10

Up to what distance can turbulence be detected on the WX radar?

Answer 10

40 nm

Question 11

What is needed for the turbulence function on the WX radar to show areas of turbulence?

Answer 11

At least some precipitation with velocity changes.
It cannot detect clear air turbulence

Question 12

Is turbulence displayed in MAP mode on the WX radar?

Answer 12

No

Question 13

What is the reason you would decrease gain to min on a WX radar?

Answer 13

If you decrease it to min and a cell is still red it means that it most likely is severe

Question 14

Do you need to change the gain when climbing into colder air?

Answer 14

No, gain is temperature adjusted

Question 15

What is the PAC alert function on the WX radar?

Answer 15

“Path Attenuation Compensation”
PAC displays a yellow arc on the outermost scale to warn the pilots of the attenuated condition
PAC shows displays up to 80 nm ahead if the aircraft
Is only available in CAL mode

Question 16

What is “Overflight Protection” and how low does it extends?

Answer 16

As the aircraft gets closer to a storm the radar tends to overscan and not show the middle part, meaning that severe weather might not show up.
The system keeps the lower levels in memory to display the middle layers and gives a more accurate picture

Question 17

Is the GCS function active during manual operation of the weather radar?

Answer 17

No

Question 18

In MAN mode, what is a good radar tilt setting below 10000 ft?

Answer 18

Between +2 to +7 deg with +5 deg being a good compromise

Question 19

In MAN radar mode, why would 7 deg setting be not such a good idea?

Answer 19

It scans along the path of the aircraft and might miss cells below the path

Question 20

In MAN radar mode, on descent, how would you operate the tilt?

Answer 20

Start with 2 deg below 10000 ft and then increase it to 5 deg

Question 21

How quickly can a thunderstorm rise, in ft/min?

Answer 21

Up to 6000 ft/min

Question 22

What does ragged edges of a thunderstorm cell on the WX radar display indicate?

Answer 22

Potential shear condition

Question 23

What does a steep gradient change of color on a WX radar display indicate?

Answer 23

Significant convective activity or turbulence

Question 24

What does “fingers” and “hooks” indicate on a WX radar display?

Answer 24

Indicates shear and turbulence
Increase avoidance distance by 50 %

Question 25

What does the different colors on the WX radar screen indicate in terms of rain fall in mm/hr?

Answer 25

Black = 0 - 0,76 mm/hr
Green = 0,76 - 3.81 mm/hr
Yellow = 3,81 - 12.7 mm/hr
Red = 12.7 - and greater

Magenta = More than 5 m/sec wind velocity

Question 26

What is the STC function on the WX radar?

Answer 26

“Sensitivity Time Control”
It compensates for beam attenuation for cells up to 80 nm
More distant cells have more energy on the target than do cells closer
Solves the problem that cells look bigger the closer they get

Question 27

What is the “Associated Threat Assessment” on the WX radar? How is it displayed?

Answer 27

Displayed by red Dots
Indicates areas of possible hail, lightning and convective activity

Question 28

What is the “Predictive Overflight Function on the WX radar? How is it displayed?

Answer 28

It shows areas of rapidly growing cells
Indicated by a red dotted area with red borders

Question 29

What is the REACT system on the WX radar display? How is it displayed?

Answer 29

Shows area of possible attenuation
Indicated by purple bend lines extending outwards

Question 30

How is predictive lightning indicated on the WX radar display?

Answer 30

A big yellow z like symbol

Question 31

How is hail indicated on the WX radar display?

Answer 31

By a yellow triangle

Question 32

How should we operate the WX radar before take-off?

Answer 32

Set Multiscan to MAN mode and set 15 deg up to scan weather

Question 33

On take-off, with the WX radar mode in AUTO, how does the MCS beams scan?

Answer 33

Lower beam is set to 3 deg and upper is set to 7 deg with the displayed average being 5 deg

Question 34

What is the best range to have on your ND so scan for weather?

Answer 34

80 nm

Question 35

What is the technique for setting the tilt on the WX radar from take-off to climb?

Answer 35

GND = Tilt +4 deg
5000 ft = +3
10000 ft = +2
15000 ft = +1
20000 ft = +0
25000 ft = -0,5
30000 ft = -1,0
35000 ft = -1,5
40000 ft = -2,0

Question 36

What is the minimum distance ahead of a storm cell do you have to start changing course?

Answer 36

Min 40 nm
If within 40 nm you will hit it