ATA 34 - Navigation Systems Flashcards
From where do the flux detector get power?
From its on side AHRS (AC power)
What are the ranges of the WXR and Flight Plan on the EHSI (Sector Mode)
WXR = 300 nm
Flight Plan = 600 nm
What do you do if an electronic flight display fails?
Operate the 3-position switch on either side. This is to cause a display transfer of the screens to form format HSI REV/ADI REV.
What do you do if an AHRS input data failure on the DPU occurs?
Operate the 3-position switch on either side to the XSIDE DATA position.
Where do the corrected altitude on the altitude indicator get registred when correcting it manually?
It will go to the pre-selector, thereafter to the ADC and then back to the altitude indicator
How many DC fans are installed in the EFIS system?
7 ea (9 ea if MFD is installed)
- One fan under each EHSI (4 ea total)
- One fan beside the LH EADI to supply cooling air to a hot spot between LH EADI and LH ASI. (1 ea)
- Underneath each DPU (2 ea)
- (If MFD installed, 1 ea fan is installed under the MFD and 1 ea fan under the MPU)
What do you need to remember when you replace an EADI?
You need to remove the inclinometer. When installing it again, the A/C needs to be levelled.
How many air data systems are there in the A/C?
3
- LH (electronic)
- RH (pneumatic)
- STDBY
How do the crew know there is a RAD ALT fail?
A red and flashing box “RA” (flashing first and then go steady) in the lower RH corner on EADI
How do you test the ADC?
On the Test 2 panel or on the ADC itself.
When testing on Test 2 Panel an additional VMO test is performed (with caution light and chimes)
What is Saab 340’s VMO?
250 knots
What is the maximum pitch movement of the magenta command bars?
±15°
How do you test the MFD system?
On Test 2 panel EFIS 1 test
Which information can be presented on the MFD?
- Weather radar data information
- Navigation information
- Page data (checklists, etc.)
What signals goes to the MFD?
The same signals as to the DPU:s
How many AHRS are there in the A/C?
2 separate but identical AHRS (system 1 and system 2)
What’s the AHRS primary function?
To provide roll, pitch and stabilised magnetic heading information for use by displays and the autopilot.
(In addition, it provides body axis angular rates and linear acceleration outputs)
Which unit is used in the AHRS to sense the horisontal component of the earth’s magnetic field?
The Flux Detector Unit (FDU). 1 unit installed in each wing. This data is sent to the attitude and heading computer
What happens when you push the HDG Slave Pushbutton?
This will force the AHC to update in accordance with
the actual flux detector signal.
(HDG Slave is inhibited with autopilot engaged)
How long does it take to power up the AHC (Attitude Heading Computer)? What do you need to remember during this start-up?
It will take approx 70 seconds and the aircraft must not be moved during this period.
What is important to remember when replacing an Attitude Heading Computer (AHC)?
That the ICU needs to remain in the aircraft on the same position.
Where is the Airspeed sensor located and to where does it feed its information?
It is located under the LH Audio Control Panel.
It feeds its information to AHRS and Rudder Limiter
When is it possible to do a Stimulus Test and where is STIM presented during the test?
Stim test mode is only possible during weight on wheels.
The word STIM is displayed on EFIS (EADI)
AHRS 1 is supplying more units than AHRS 2. Which units are exclusively supplied with information form AHRS 1?
- Weather Radar System
- FDAU (FDR)
- FMS
- EGPWS
