Offset Localiser at VMMC Rwy 16

[mikeindevon]

I have been trying this approach and have successfully built an approach using the FMC legs page.  The FMC recognises MCS on the legs pages.  However, I haven't been able to tune to it on the NAV Radio page.  I wonder if this is the way things work in real life or some omission in the nav database.

As it is, with nothing on the ND to help, you have to rely on LNAV to hold the MCS course and make the turnoff at D2.6.  The chart I am using is at http://www.fly-sea.com/charts/VMMC.pdf.

A second question.  I take off from VHHH 7L for which the chart says continue on the runway heading until you have passed ROVER and then turn right towards RAMEN.  This is to avoid the mountains.  If you program that as a route, the FMC cuts the corner off by starting the turn before reaching ROVER.  How would you fly that in practice?
- use HDG HOLD and then revert to LNAV after passing ROVER
- add another WPT passed ROVER and program that into the route?

Chart at http://www.fly-sea.com/charts/VHHH.pdf

Mike

[skelsey]

Hi Mike,

In both cases, are you selecting the procedure from the navigation database or are you 'building your own'? Are you manually tuning 111.6/217 in the ILS tuner or waiting for it to auto-tune?

In the case of the SID -- if you are 'building your own' then the B744 FMC treats all waypoints as "fly by" - in other words it will lead the turn in order to establish neatly on the outbound track. The problem is that ROVER in the ATENA2C departure is a "fly over" waypoint; this should be coded in the procedure if you selected it from the database but you cannot (AFAIK) manually set a "fly over" waypoint in the B744 FMC, unlike the Airbus for instance.

[mikeindevon]

Many thanks for the above.  Very helpful.  I had tried entering the 111.7 on the VOR line - no go.  I also tried in the ILS, but forgot the /217  so no go again.  I have got it right now and I will try flying it.

Never knew about fly-by and fly-over wpts.  The Bill Bulfer book says on p26 "Pilot defined wpts will be fly-by wpts" and further down "Database defined wpts can be coded to either fly-over or fly-by a point."  The book suggests as a workaround creating a wpt a mile or two further on, which is what I did.  You are absolutely right - thanks.

Mike

[Hardy Heinlin]

The FMC recognises MCS on the legs pages.  However, I haven't been able to tune to it on the NAV Radio page.

I am able to tune MCS. As expected, it tunes if I select a LOC 16 approach from the DEP/ARR page, or if I enter 111.7/217 in 4L on the NAVRAD page.


Cheers,

|-|ardy


P.S.: A tip for the missed approach altitude at VMMC: It's 5910. Set the MCP altitude to 5900 before going around. When the missed approach starts, the FMC sets the CRZ ALT to 5910 because that's the highest constraint in the route. Once in climb, set the MCP to 6000. If it's at 5900 the FMC will think there is an MCP intervention (10 feet below CRZ ALT) and the level-off logic will be confused.

[mikeindevon]

Missed approach! What's that?? 

ps: thanks Hardy, I'm good with the tuning now.