Weather Radar & Collision Warning Systems

Question 1

What is weather radar used for?

Answer 1

The detection of CB due to the presence of moisture or hail (GR)

This implies presence of:
- Strong turbulence
- Windshear
- Lightning
- Severe icing

Question 2

Maximum range of weather radar?

Answer 2

Approx. 250 NM

Question 3

True or false. A weather radar beam is safe.

Answer 3

False. The beams of a weather radar are hazardous and as such they must be disabled on the ground.

Question 4

What are the elements of a weather radar?

Answer 4

• Operates in the X-Band and is part of the microwave region on the radio wave spectrum.
• Beam is hazardous
• Must be disabled on the ground
• Antenna is gyro stabilised
• Displayed to pilots on a screen or EFIS

Question 5

What are the limitations of weather radar?

Answer 5

• Is not a 3D picture
• Suffers from masking/radar attenuation (shadow)

Question 6

Pilots can tilt the weather radar up and down up to ___________

Answer 6

15 degrees

Question 7

What does a stormscope do?

Answer 7

Detects and maps the radiated signals of electrical discharge.

Question 8

Advantage of stormscopes over traditional weather radar?

Answer 8

Traditional weather radar may not display a storm due to a lack of liquid water within.

Question 9

TCAS

Answer 9

Traffic Collision Advisory System

Question 10

Elements of TCAS

Answer 10

• Actively interrogates other aircraft transponders
• Displays their position and altitude relative to the TCAS aircraft
• Calculates trajectory and time to the closest point of approach
• Provides Visual and Aural warnings
• TCAS2 issues vertical manoeuvring instructions to resolve a conflict.
• TCAS calculates a time to reach the CPA (Closest Point of Approach) with the intruder, by dividing the range by the closure rate. This time value is the main parameter for issuing alerts.

Question 11

How will aircraft with only a Mode 3/A transponder appear on a TCAS?

Answer 11

Lateral position.

Question 12

Which SSR modes provide vertical position information to TCAS?

Answer 12

Mode C

Mode S

Question 13

TCAS symbols/meanings

Answer 13

Hollow diamond - other traffic
Solid diamond - proximate traffic
Yellow circle - TA
Red square - RA

Question 14

TCAS data tag will indicate what?

Answer 14

Other aircraft’s distance above/below you and direction (climb/descent).

10 = 10 1000ft.

Question 15

In the case of a Traffic Advisory, the pilot will attempt to establish ______________ and change the flight path only if a ______________ visually.

Answer 15

1. Visual contact
2. Collision risk is established

Question 16

In the case of a Resolution Advisory the pilot will respond in accordance with the _______________ prescribed by the TCAS system.

Answer 16

Collision avoidance manoeuvre.