[jhb_airlines] Re: Radio Nav

  • From: "Bones" <bones@xxxxxxx>
  • To: <jhb_airlines@xxxxxxxxxxxxx>
  • Date: Tue, 21 Dec 2004 21:56:29 -0000

I'd like to suggest a slightly different procedure here. Because you =
two options for directional control it's best to make full use of both. =
mode is more flexible in that you can easily alter your heading as you =
but if CRS/NAV mode is selected and you are tracking a radial then you =
touch NAV1 at all (except the standby frequency).

Let's use you original EGPD SAB NEW route for this example.

On departure tune NAV1 into the first en route beacon (SAB, not ADN) and =
up the correct radial (about 185 at a guess) in the CRS/NAV box. You =
be able to get this value from FSNav or your flight plan - and you =
keep this figure in your head. Set the standby frequency to the second =
en route (NEW). At the same time set the HDG value to runway heading.

On take off engage AP in HDG and ALT modes so the aircraft initially =
runway heading and begins a climb to the first assigned level. Stay on
runway heading until you have got gear up and cleaned up the flaps - =
not unusual to fly out to around 4nm before turning on track. The =
here is when flying a SID but any SID's that require turns within 4nm =
be left alone until you get more familiar with the aircraft and your
reactions are faster. If you are happy to start turning before you have
completed the flap sequence then alter the HDG value to match the track =
memorised - 185 in this case. This will put you roughly on course to SAB
whilst leaving you free to complete the after take off checks.

Once the aircraft is tidy you can now concentrate on your navigation. =
autopilot will be pointing you in the right direction now (in HDG mode) =
a glance at the HSI may show you that you are slightly left or right of =
185 radial between ADN and SAB. Alter course on the HDG bug to fly an
intercept for the right track and once you are on a closing heading for =
radial switch the A/P from HDG to NAV mode and let it capture and fly =

The point I must make here is that routes along airways and for =
approach procedures are not rigid - they are guidelines for flying. You
don't have to get neurotic and fly the exact path shown on the plates
because then you would be spending too much time navigating rather than =
aircraft handling. An aircraft flying from Aberdeen to SAB would never =
off and turn back to the ADN beacon before setting course for SAB - he =
just turn direct to SAB and gradually intercept the ADN - SAB radial. =
with turning from one VOR to another - you don't fly directly over the
beacon very often. As one Trident pilot remarked on flying the dogleg =
from Jersey to SAM to MID - "If we flew north until we hit SAM and then
turned right to MID we would end up 8nm north of the airway."

As you track towards SAB take a look at your actual heading as this will
give you a rough idea of any drift. Set this value in the HDG window as =
will need it. Approaching to within 10nm of SAB VOR switch over to HDG =
to free up the NAV selector. Switch NAV1 over to NEW frequency (flip the
frequencies if you use a radio with a standby option) and dial up the =
(sic) course in the CRS/NAV selector (166). At the same time dial up the
next en route point frequency in the standby frequency box.

You are now flying on HDG mode and your display will no longer be =
you the radial to SAB because you have reset it to NEW. It doesn't =
that you have lost course guidance because you are hardly likely to =
much from your original track in the few miles to run to the VOR. If you =
the HDG value to the heading shown on the HSI at the time you =
the NAV mode you will still pass within half a mile of the beacon. =
this is immaterial because now you are looking at the HSI to lock on to =
next radial to NEW.

It is most likely that the needle will start off at full deflection but =
you get near to the beacon it will come alive and start moving towards =
centre. As soon as you see the needle moving you can re-engage NAV/CRS =
and let the autopilot capture the new radial. And so it goes on...

If the explanation above baffles you then what I could do is set up an =
session (or FPI) and talk you through it.


-----Original Message-----
From: jhb_airlines-bounce@xxxxxxxxxxxxx
[mailto:jhb_airlines-bounce@xxxxxxxxxxxxx] On Behalf Of frank fisher
Sent: 21 December 2004 19:41
To: jhb_airlines@xxxxxxxxxxxxx
Subject: [jhb_airlines] Radio Nav

Perhaps I am wording it wrong.
I set Nav1 stnby to the first beacon, rotate dial to get heading, take =
and switch it Nav1 active, with AP on and HDG, the AC turns to and flies =
the beacon, to/from is facing up. I then set the Nav1 Stby to the next
beacon ready, at the time, switch it to active and tune the Stby to the =
beacon. The to/from flag is now down, and what ever I do, the AC will =
try to
backtrack. I get the impression I am still locked on the first beacon, =
cannot change it. Last night, in desparation, I tried for the very first
time, to use the ADF, after realizing that the two sets of numbers at =
airfield in FSNav, refer to a) the Nav Frq B) the ADF Frg.(this after =
10 years of playing around with FS, I said I was a dumbo). This was =
EGNC and EGNT. I have tried setting the same Frg in both the Nav1 and 2
active and Stby, no joy. To recap, left EGGP for WAL, got to Wal then =
to get to WL then EGNC, finally got to EGNC, after a lot of choice =
then discovered ADF which got me to EGNT. Anyway, will not bother you =
more this year, as we all will be busy, perhaps we can hook up via TS or
messenger in the new year, and talk it through, Email is fine, but too =
and clumsy. Frank F

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