Star query

[kessler1]

Hiya,

I posted recently on here about some sim time I have booked - which is now rapidly approaching! - and was given some good advice, namely to fly a different approach to that which I was going to request in the sim. So, I have been practicing hard! I want to fly EDDF to EDDT, culminating in a ILS landing to RWY 08L, flying the Rudak 4Z approach. I'm now quite familiar with it but there is one part that I am having trouble with. Basically, the approach chart states that from LERSI, fly on radial 017 until 25.6 miles from LWB and then make the turn to final for localizer capture. However, in the aircraft I fly on my sim - A320 - turning at 25.6 miles results in coming out of the turn too far to the right and failing to capture the localizer. after trying several turns, I worked out that I have to fly until 24 miles from LWB and then make the turn in order to capture the localizer.

So, ideally, could someone who has perhaps flown this approach for real and in the A320 offer some advice? Mainly, in the real world, should the turn to final be made at 25.6 miles as indicated on the chart? Or does it depend on which aircraft is being flown as to whether you have to turn later or earlier than specified on the chart? As a mere flight enthusiast and simmer, I like to try and fly as close to real as possible (dont we all?)

I guess in the real world also, the approach would be flown by the mcdu and indeed on my sim I have also programmed the approach into the mcdu and flown it, done this way however, the procedure is to fly from LERSI on 024 to fix LIGBA and then turn to final and localizer capture. I just wanted to fly the approach using manual input and as per the chart.

I'm always a bit reluctant to post on here, with me only being a flight sim person, but its always nice to have it from the horses mouth as it were!

Many thanks,

Rory

[bingofuel]

Try slowing down, it should tighten the turn for the same bank angle

[kessler1]

Ok, I'll try slowing down more, but at the point of the turn I'm about 12 miles from the runway and typically I've dropped speed down to about 170kt by then. Should I be even slower? I usually go for gear down at about 8 mile out. final app speed is typically 150 with landing speed around 140. But thinking about it, is it really a tightening up of the turn I need? As I'm coming out of the turn too far to the right of the localizer?

[welliewanger]

1. RUDAK4Z is BRNAV only. This requires you to be within 5NM 95% of the time.

2. The D25.6 waypoint on the transition is not a "fly over" waypoint.

I don't fly the bus, but in my aircraft 200 kts is a sensible speed for the turn. But we tend to fly faster, 'cos it's more fun! I dunno about airliners but 170kts seems sensible. Flying slower will reduce the radius so you're less likely to overshoot. However (due to the above two points) you can also start the turn earlier.

[kessler1]

Its probably my inexperience, or I'm not explaining my situation properly, but rather than overshooting, as I see it, I'm undershooting. As I make my turn and come out of it, with the airport/runway ahead, I'm too far over to the right of it, ie, Airport/runway too far to my left. I know I'm only flying Microsoft FSX but, interestingly, if I fly this approach with one of the sims default aircraft ( B737-800) I make the turn at 25.6 miles and there is no problem at capturing the localizer. This led me to also think that aircraft size was a factor, with the B737 being longer than the A320.

I know the instructer will have his own input on this when I get in the sim but would be nice to be doing it right before then. The sim is in Berlin, an A320, fixed base but good.

[hvogt]

I'm afraid I can't tell you anything specific to the A320, just some IFR basics.

If you undershoot the localizer you have initiated the turn too early. My recommendation would be to fly until 25.6 DME LWB and turn right to an intermediate heading of 049°. As soon as you see the CDI to start moving you can intercept the localizer.

By the way, RUDAK 4Z is not an approach, it's an arrival route.

Have fun in the sim!

[kessler1]

Thanks for the reply. I didnt realise that RUDAK4Z was an arrival route and not an approach! I've been flying as per the ILS or NDB rwy 08L chart provided by Navigraph, but looking at the STAR for traffic arriving from the south, you're absolutely right!

My problem was indeed a speed problem, but I was going too slow as opposed to too fast. I increased speed to 200kts and the capture was smooth and trouble free. I understand what you mean about turning to 049 until localizer is alive, with it being 30deg less than the final approach course.

Thanks to all who replied. My sim time is booked for Sat 22nd Oct and I'm hoping for a trouble-free flight :hmm:

Rory