Hi,

 

How do you lock a VOR course insterted into the NAV of the FMC?

 

Thanks,

Christos

 

On the NAV/RAD page, instead of entering either 113.60 or ABC, you would enter either 113.60/273 or ABC/273

 

You can of course enter /273 on its own as well. Note that the station becomes manually tuned at this point. This is how you set the CDI in VOR mode, too.

 

EDIT: I see you specifically want to track a VOR radial entered into the FMC.

 

Do an intercept and use a course-to-fix? Not sure if entering ABC/123 will do it as well. AFAIK it can only fly to a point defined by a P/B/D or PB/PB.

 

Let's say you are 15 nm from the beacon. What you could do is enter:

 

ABC/273/10

ABC

 

This will then intercept the radial at the point defined by the PBD, then it will turn inbound to intercept the VOR along the 273 radial by default. Note that this is not allowed if you are attempting to fly a VOR procedure; you must be tracking the actual VOR station and following the radials thereof.

 

IIRC there is no way to persuade the autopilot to track a VOR radial automatically.

 

Best regards,

Robin.

You can use TRK SEL too which will compensate for wind drift  ^_^ I've not needed to track a VOR that's outside of a SID/STAR or my flight plan - however that's the way I'd do it. Also put the VOR/Radial in the FIX page. 

Small problem: flying VORs programmed into the FMS and flown using LNAV is *NOT* tracking the VOR! This would not be permitted on an instrument approach, because the reference MUST be the VOR radial from the beacon, not some computer interpretation of IRS position data.

 

The only method I know of flying an actual VOR radial is using the heading selector or manually flying the aircraft. There is no dedicated VOR mode for radial tracking that uses the VOR data directly.

 

On the MD-11 there is the option in the NAV RAD page to ARM VOR. It *WILL* track the VOR station properly (NOT using the FMS), but there seems to be no equivalent function on the Boeings.

 

Best regards,

Robin.

Small problem: flying VORs programmed into the FMS and flown using LNAV is *NOT* tracking the VOR! This would not be permitted on an instrument approach, because the reference MUST be the VOR radial from the beacon, not some computer interpretation of IRS position data.

 

The only method I know of flying an actual VOR radial is using the heading selector or manually flying the aircraft. There is no dedicated VOR mode for radial tracking that uses the VOR data directly.

 

On the MD-11 there is the option in the NAV RAD page to ARM VOR. It *WILL* track the VOR station properly (NOT using the FMS), but there seems to be no equivalent function on the Boeings.

 

Best regards,

Robin.

I think you can fly a VOR approach in LNAV, it's called an overlay iirc. You do have to monitor raw VOR data though.

 

 

it's called an overlay iirc.

 

Ahh yes!

 

Best regards,

Robin.

Now, as far as I understand from the above posts there is no such simple think to capture a VOR radial as on the MD-11?

Strange. Don't the T7 pilots fly VOR radials at all?

 

Christos

 

Now, as far as I understand from the above posts there is no such simple think to capture a VOR radial as on the MD-11?

Strange. Don't the T7 pilots fly VOR radials at all?

 

Christos

 

Correct, and great question. I often wondered why Boeing never offered the ability to track VOR using the autopilot, yet they offered the relatively useless IAN approach mode. :unsure:

 

Best regards,

Robin.

4

I often wondered why Boeing never offered the ability to track VOR using the autopilot, yet they offered the relatively useless IAN approach mode.

 

Because it's not the 60s anymore... LNAV/VNAV, RNAV/RNP. Also if you insist on VOR for whatever reason, the disconnect button still works.

 

 

[...] yet they offered the relatively useless IAN approach mode.

 

Useless why?

Ok, let somebody give me an example on how to fly the following VOR radial with the T7:

 

Approach to the old VHHX (Kai Tak) airport, runway 13.

According to the chart after reaching the CH (VOR/DME) you follow its radial of 270 degrees for 7 nm and then turn right to the SL (NDB).

 

How do you follow the 270 radial of the CH VOR?

 

Christos

 

In the 777 - manually, using VOR rose mode. I might cheat and use heading select in track mode, but otherwise, no dice.

 

@Kyle: because it is a non-precision approach, and what is wrong with FPA vertical mode? IAN also assumes 3.0 degrees, which I'm not sure can be altered. Try flying one of the NDB or VOR approaches into Innsbruck.

 

Best regards,

Robin.

 

 

I often wondered why Boeing never offered the ability to track VOR using the autopilot, yet they offered the relatively useless IAN approach mode.

 

Given that we're in the 777 forum, I'll assume that's the plane we're talking about here.. I thought IAN was not offered on the 777? If we're talking about the 737, it can track a VOR radial on A/P.

Well there is a mistake in the FMS, because there is an option for IAN. I'm fairly sure I tried it, too.

 

Best regards,

Robin.

Not sure about the 777 - haven't had IAN on it when I flew into Innsbruck. (I tried).

 

As for the 737, IAN follows whatever vertical profile is appropriate, not neccessarily 3 degree glide.