NAV - Sources and ILS Approach
I am new with the Dash-8 and I have some question about the NAV - Sources on a ILS Approach.
As I understand we have waypoits and airways of a route, including the STAR, based on GPS Coordinates, supported sometimes by VORs. This in programmed in the FMC.
When I select as NAV-Source "FMS1" and push NAV it follows the lateral route, additional I can select an Altitude or an VNAV or a VS decent.
The other thing ist the ILS Signal, wich comes from the ground from the "end of the runway", a 3° glide slope. So we can intercept the signal at a specific waypoint and specific altitude.
At a specific point we have to switch from GPS (Waypoint) Navigation to the ground-based ILS Glide-slope.
What I did in the last flights: In the FMC I "ARMED the APR" while I decent with VNAV and 1-2 miles before the "ILS Interception point" I changed the NAV Source with the knob from "FMS1" to "ILS1" and press APPROACH, then the plane start the decent along the glide path. I deactivated the Autopilot at 600 ft and landed by manualy. Fine.
But is this the right way to do?
Is there a good tutorial for this phase of the flight?
Because the tutorial flight is a little bit confusing...
I could arm the approach mode of the FMS by pressing "ARM APPROACH", but I could not arm the "TUNE APPROACH"
on the NAV page?
from the tutorial:
Descend: After passing the TOD, reduce PL to maintain 240kts. Switch on passenger signs, set decision altitude (DA) (set 60ft in our case). passing FL100, set the destination airport pressure of 29.97 Inches, select seatbelts to ON and turn on Landing Lights. When passing the HABBS waypoint we will begin our approach preparations:
Propeller and airframe deicing OFF
Standby fuel pumps ON
Auxiliary Fuel Pumps ON
GPWS flaps selector to 15
Arm the approach mode of the FMS by pressing "ARM APPROACH" and than "TUNE APPROACH" on the NAV page. This will also tune the correct ILS frequency at the NAV1 receiver. Bring up the NAV CDI pointer on the MFD by pressing the FORMAT button for >2 seconds, and set the ILS course of 58 degrees. We are now ready for the approach
Shortly after passing HABBS the FMS will enter the approach mode, and the VNAV will also switch to approach mode, thus showing the simulated glideslope, and disconnect automatically cause we are below the glide slope altitude. It is theoretically possible to select ALT, re-engage the VNAV and fly a fully automatic FMS ILS approach, however for the purpose of this tutorial we will use the regular ILS approach in order to demonstrate the related autopilot functionality.
Upon the VNAV disconnect, set VS and ALT SEL to maintain the current vertical speed following by leveling off at 3000ft, the HDG bug to the current heading, press "HDG" to engage the "HDG SEL" mode, and . Switch NAV SOURCE to NAV1, and press APPR to intercept the ILS. Watch out IAS. Using PL, reduce the speed to under 200kts and deploy flaps to 5 deg. Switch on landing lights. Continue reducing speed, under 180kts set landing gear down and flaps to 10 deg. Approaching 1000ft, turn the bleeds OFF/MIN, advance the Condition Levers to MAX and disengage the autopilot by pressing the AP button on the glareshield or the red button on the yoke."
Thanks for help!