STAR - chart vs FMC

[Paul_Yorks 97]

This probably isn't a NGX-specific issue, but it came up whilst I was using it, so I'll try here.

 

I'm flying into Cork, Ireland, from London EGSS - here's my STAR chart: http://www.iaa.ie/safe_reg/iaip/Frame1.htm

 

My last flightplan WPT is VAPAL, so I choose the VAPAL1G STAR with a view to landing ILS on Rwy 35.

 

A couple of linked questions:

 

1 The racetrack/hold depicted on this chart doesn't appear in the FMC. Compare that with e.g. the STARs into EGSS where the FMC automatically routes you into and around the stacks. Is there a reason for that? Is the AIRAC accurate? (I'm using the default that came with the NGX) Or is the racetrack not part of the STAR (it doesn't appear, btw, on any of these STARs once you select in the FMC)

2 What then to do about shedding speed after ROBVO, that I have to cross at 6000 or above? - there's not a lot of route left to get down to GS height and get your speed down. The FMC has you crossing ROBVO at a good lick of speed (220 - 250 if memory serves). So far I have got round this by specifying a lower crossing speed in the FMC, alternatively just hitting speed intervene and winding it down/applying spoilers to get my speed down. Is this a reasonable way to do it? Should I set up a hold at say ATLAM/GOSDA, as the chart suggests, and use the circuit to shed speed? Is that the sort of thing that might be done in the real world?

 

Any comments welcome. I've messed around with STARs and SIDs for a while now but still find myself puzzled as often as not.

 

Paul Scholey

[borgfan 1]

I've flown that route a few times, one of my favourites.

The hold at GOSDA isn't part of the STAR, so dont worry about it.

 

I'd be at 200-220 at ROBVO with a bit of flaps to help and using manual speed control. Hit ATLAM at 180 Flap 5 and get it down to 160 at GOSDA Flap 15 and gear down. If in doubt slow down earlier rather than later, I tend to fly STARs with HDG select and manual speeds just so I can keep on top of it. Hope this helps.

[rocketfs 2]

Hi, here my Two cents:

 

1) I think the holding is both part of the approach procedure as part of the STAR when ATC needs to put you somewhere. I don't think Cork is busy enough to have standard stacks.

 

2) Looking at the other approaches, and at the IAC for ILS RWY35, you are obliged to fly the holding as part of the procedure. In this way you have all the time to reduce speed at lose altitude.

In the real world you would receive radar vectors. I don't think the controller would make you fly a racetrack.

 

Now I have a question: I don't see an Initial Approach Fix, so I think the Intermediate Fix serves as IAF. If you are not cleared for the procedure, you cannot fly the procedure and have to enter the holding. But in this case, the STAR tells you to be at 3000' at GOSDA, which is exactly the altitude another aircraft will be at for the instrument appraoch. If I'm correct, that's pretty dangerous. Since people making these charts aren't stupid, it must be something I don't understand...

 

 

 

Best Regards,

Bert Van Bulck

[Spin737 102]

You should have plenty of time to configure for this approach. Be proactive on the configuration if you need to be, but don't alter any altitudes. That's a definite no no. ROBVO is about 19nm from the threshold. You would normally start to slow from 250 at that point. ATLAM is 12nm, start configuring there at the latest.

 

What happens if you leave the jet with in VNAV (with APP armed)? If you follow the speeds with the appropriate configuration, you should make it no problem.

[rsvit 16]

You should remember, that actual descend clearance would be given by ATC.

 

I would use VNAV calculations and retract flaps on scheldue, have flaps 5 on localizer capture, set 160kt, at 4nm prior to runway gear down flaps 15.

Here are some speed restrictions.

 

[Paul_Yorks 97]

Thanks for all the comments.

 

Radar Contact descended me a good bit ahead of time - but after the 6000 crossing at ROBVO (I think it was) I was unable to get configured for landing. Ended up at the right height, but about 198kts as I hit the runway threshold, so had to go around. Even with plenty of drag (including early flaps) I couldn't descend in time. VNAV won't do it. That's what led to my OP - in other scenarios VNAV has brought me perfectly to the approach, but here the setup is more difficult, and I was wondering therefore about the use of the hold to ensure descent/speed.

 

I'll try to post some screenshots to illustrate the point more clearly, but will need to refly it.

[rsvit 16]

http://www.flightrad...08/18:24/EIN723

 

Here ground speed shown. But it's look like enough time to slow down and descend. It must 7 to 11nm for that.

[Spin737 102]

Remember, the landing gear is a much better speed brake than the speed brake. Don't hesitate to use it.

[borgfan 1]

I've done this flight a few times on the PMDG 737-800ngx and it is a slippery customer. Trick is not to leave it up to vnav speeds all the way. Get on speed intervention after Robvo and slow it down with flaps and gear when appropriate. I've not needed speedbrakes albeit that the FMC warns that descent isn't possible after Atlam.

 

Reviewing the plates, the full procedure does include a run around the hold, but its not necessary in order to slow down. Best thing about the sim is that you can just try different techniques - just worth remimbering that you are in charge of the aircraft not the FMC :) Good luck - its is possible to do what you want.

[Paul_Yorks 97]

its is possible to do what you want.

 

Yes, and I landed it perfectly first time today by not relying on the FMC - but it's good to know that others have tried this, and that I'm not going off the beaten track by trying some other ideas. I think I originally got into a "VNAV will sort it all out" mindset - I'm now learning that this is just wrong - Vnav's a good servant, but a bad master, I reckon.

 

Thanks again for all the helpful comments.

[joostdewit 0]

I've done this flight a few times on the PMDG 737-800ngx and it is a slippery customer. Trick is not to leave it up to vnav speeds all the way. Get on speed intervention after Robvo and slow it down with flaps and gear when appropriate. I've not needed speedbrakes albeit that the FMC warns that descent isn't possible after Atlam.

 

Reviewing the plates, the full procedure does include a run around the hold, but its not necessary in order to slow down. Best thing about the sim is that you can just try different techniques - just worth remimbering that you are in charge of the aircraft not the FMC :) Good luck - its is possible to do what you want.

 

What if you want to fly the holding. How do you set it up correctly in the FMC ? Is it 345/L ?

[borgfan 1]

What if you want to fly the holding. How do you set it up correctly in the FMC ? Is it 345/L ?

 

Yes that should do it if you are holding between 3000-5000 feet.

Between 5000' and FL80 refer to the note: "For holding above 5000 or if ICN DME U/S, track CRK 344, FAP D8.5 CRK. Limit OUTBD D13 CRK. "