Navigation

Question 1

Which battery bus powers the weather radar?

Answer 1

Right 115v fixed frequency AC bus.

Question 2

Where are the weather radar receiver transmit unit, antenna and antenna servos located?

Answer 2

In the aircraft nose.

Question 3

What is the RCT function on the weather radar?

Answer 3

Radio Echo Attenuation Compensation Technique. Areas that the radar can’t accurately depict weather due to attenuation are coloured blue.

Question 4

What is the GCR function on the weather radar?

Answer 4

Ground Clutter Reduction. GCR when activated removes returns that have a high probability of originating from a ground return.

Question 5

What is the gain knob used for on the weather radar?

Answer 5

Adjusting the sensitivity of the radar receiver primarily to resolve nearby strong target signals while ground mapping.

Question 6

What are some of the inputs to the FMS?

Answer 6

GPS, DME/VOR, ADC, AHRS, fuel flow.

Question 7

Are the Cobham FMS GPS only or multi-sensor? What type of long range sensor do they use?

Answer 7

Multi-sensor and use GNSS for the long range sensor.

Question 8

What is BCP in relation to the FMS? How is it represented?

Answer 8

Best computed position where the FMS is certain to 95% of the aircraft position. It’s expressed as ANP (actual navigation performance) and is expressed in NM.

Question 9

What type of FMS do we have at Cobham?

Answer 9

UNS1E 80x

Question 10

If you see GPS INTEG on the glareshield annunciator, what does this mean?

Answer 10

The GPS computed position has exceeded the RNP for the particular phase of flight.
Also indicates a loss of RAIM.

Question 11

Where do you find the GPS integrity status? What are some of the things that could be displayed?

Answer 11

Data page 2 
RAIM 
RADIO 
NONE
ALARM

Question 12

What warnings will you get if the GPS solution value exceeds the horizontal integrity limit for the phase of flight (RNP)? How about if overall ANP exceeds RNP?

Answer 12

GPS INTEG on the glareshield annunciator

may also cause POSITION UNCERTAIN message on FMS if other inputs (VOR, DME) are not able to keep the ANP BCP below RNP.

Question 13

If the GPS INTEG message appears, can you continue navigating using GPS?

Answer 13

If doing an RNAV need to conduct missed approach, select heading and Climb above LSALT.
IF enroute, and there is no POS message commence timing. If GPS INTEG message goes out within 5 minutes it’s okay. If message still exists after 5 minutes need to navigate by alternative means.
If POS light illuminates at any time, select HDG and VOR/LOC