RADALT, TCAS & TERPROM

Question 1

How does the Rad Alt work?

Answer 1

Uses reflected radio beams to present a precise reading of vertical separation between the a/c and terrrain over which it is flying

Question 2

What are the components of the Rad Alt?

Answer 2

Rad Alt (right hand avionics bay)
Antenna (bottom of fuselage)

Question 3

What are the limitations on the RadAlt in HUD/PFD?

Answer 3

• Only active when pitch angle is less than 15 deg NU or ND and bank angle less than 30 deg
• Only active when a/c is at or below 2500 ft AGL
• Erratic RadAlt operation may occur while the speed brake is deployed
• If HUD declutter level 2 is selected the Rad Alt indications on HUD and PFD will dissapear

Question 4

What are the indications of RadAlt fail?

Answer 4

• The HUD displays the symbol R XXXX in the RadAlt box
• The PFD readout is replaced with a red X
• The TCAS becomes inoperative and the NAV display will show a TCAS FAIL

Question 5

What is TERPOM?

Answer 5

Terrain Profile Matching
Uses nav and Rad Alt data to determine an aircraft’s location above the surface and warn the pilot if it detects or predicts the close proximity to obstacles/ground.

Question 6

What is PGCAS?

Answer 6

Predictive Ground Collision Avoidance System

Question 7

What is the pre-set warning height of the PGCAS?

Answer 7

100 feet

Question 8

What are the components of the TERPROM?

Answer 8

TERPROM control panel (RHS of instrument panel)
TERPROM processor (LHS avionics bay)

Question 9

What powers the TERPROM?

Answer 9

Power via generator bus circuit breaker, system is not powered until the generator is brought online and the avionics master switched on.

Question 10

True or false: When landing gear is down, all aural and visual TERPROM alerts are inhibited

Answer 10

True

Question 11

How does TCAS work?

Answer 11

TCAS detects and tracks other aircraft by interrogating their transponders

Question 12

True or false: During inverted flight, traffic will be displayed as if the aircraft were upright

Answer 12

True

Question 13

What components does TCAS use?

Answer 13

Multi functional display
UFCP
Avionics Master switch (to apply power to the TCAS)
IACs
Transponder
RadAlt (to tell TCAS the aircraft is airborne)
CBs
TCAS processor/transmitter
TCAS control unit
TCAS antennas

Question 14

What are the 3 TCAS modes that can be toggled on the UFCP?

Answer 14

Normal (tx between 2700 ft above and 2700 ft below are displayed)
Above (tx between 8700 ft above and 2700 ft below are displayed)
Below (tx between 2700 ft above and 8700 ft below are displayed)

Question 15

What 3 types of traffic does the TCAS system display?

Answer 15

Non-threat traffic (unfilled white diamond)
Proximity intruder traffic (filled white diamond)
Traffic advisory traffic (filled yellow circle)

Question 16

What does a downward pointing arrow on traffic mean?

Answer 16

The traffic is descending

Question 17

A circle of ____ dots appear when the display range is set to 10nm or less

Answer 17

Blue

Question 18

What are the 2 TCAS sensitivity levels?

Answer 18

A and B

Question 19

What is TCAS sensitivity level A?

Answer 19

When landing gear is extended. A TA will be issued when one of the following conditions is met:
- TCAS calculates that if the closing rate with the intruder aircraft is maintained, vertical separation of less than 600 ft will occur in 20 seconds
- Vertical separation from the intruder is less than 600 ft and horizontal separation is less than 0.2 nm
- Horizontal separation from non-altitude reporting intruder is within 15 seconds or 0.2 nm

Question 20

What is TCAS sensitivity level B?

Answer 20

When landing gear is retracted. A TA will be issued when one of the following conditions is met:
- TCAS calculates that if the closing rate with the intruder aircraft is maintained, vertical separation of less than 800 ft will occur in 30 seconds
- Vertical separation from the intruder is less than 800 ft and horizontal separation is less than 0.55 nm
- Horizontal separation from non-altitude reporting intruder is within 20 seconds or 0.55 nm

Question 21

True or false: TCAS audio messages are not inhibited when landing gear is extended

Answer 21

False

Question 22

How do you operate the TCAS self test?

Answer 22

Hold LSKR2 on MFD for 2 seconds