# 45 deg intercept on KFAT OAL4 SID for RWY 29R

The chart calls for a 292 heading until 2000ft, then a climbing right turn to intercept the 025 course to FRA VOR.

This is currently coded as a 292 heading to 2k, then a 340 heading to intercept the 025 course.

Is this intentional? I imagine the 45 deg intercept is no accident. Procedurally, I’d prefer it wasn’t there and simply let the FMS handle the steep intercept (it’s perfectly capable of handling the turn anticipation).

Is this standard when these procedures are coded to build a in 45 deg intercept?

Thanks for any assistance.

Hi,
yes absolutely - there are no limitations on turn degrees. You will also find procedures with 360 turns, 180 turns … It’s not like a ILS intercept, where the recommendation is to intercept it with not more of 30 degrees and also here it’s only a recommendation and not a rule - to avoid overshooting the ILS signal.

In short, there are no coding rule standards for such intercepts.

Hope that helps
Richard

That being the case, why does the coded procedure call for a 340 heading to intercept the 025 course to the VOR, when no such guidance exists in the text/graphic of the SID? Why not simply have the 292 heading, then intercept the 025 course to FRA as the SID shows?

Sorry, I can’t really follow you … where do you see a 340 heading? There is no such heading in our data nor on the charts.

So, from where do you have this heading?

Cheers
Richard

From the CIFP\KFAT.dat file

SID:010,1,OAL4,RW29B, , , , , , , ,VA, , , , , , , , ,2920, ,+,02000, ,18000, , , , , , , , , , , , ;
SID:020,1,OAL4,RW29B, , , , , , , ,VI, , , , , , , , ,3400, , , , , , , , , , , , , , , , , ;
SID:030,1,OAL4,RW29B,FRA,K2,D, ,VE , , ,CF, ,FRA,K2,D, , ,0000,0000,0250,0160, , , , , , , , , , , , , , , , ;

That’s a 292 heading until 2000ft, then a 340 heading to intercept the 025 course to FRA.

Hi,
thanks for the additional information - it´s a little bit hard supporting a question without such details.

Yes, this heading is necessary for the intercept. As you see in the coding line the VI leg path which means heading to an intercept - so the heading 340 guarantee you that you intercept the R205 …

The ARINC coding rule for VI needs at least a “heading” - therefore the 340 heading … it´s only for the intercept and absolutely correct.

Cheers,
Richard

Hi Richard,

Apologies, I assumed that by listing the SID name, it’d be redundant to post the actual encoded procedure. I’ll keep that in mind for the future.

So, to the original question, then…the textual/graphical procedure makes NO reference at all to a 340 heading. So, why is the coded version including a 340 heading to intercept rather than the 292 heading that’s charted?

Keith

Hi Keith,
the 292 heading is coded. The 340 heading is necessary for the intercept. As an example:
What, when an a/c reach the 2000 ft before the R205 FRI … then the a/c makes the right turn on heading 025 but will never intercept the R205. Therefore the coded 340 heading, to be sure that the a/c intercepts the R205.

The charts and the coding can be differ - the results must be the same.

Cheers
Richard

Hi Richard,

The 292 heading is coded up to 2000ft. Why not continue on a 292 heading for the intercept after that? As a pilot, the chart says “climbing right turn” to intercept the FRA R-205. In this case, upon reaching 2000ft, we’re turning to an arbitrary 340 heading for quite a long time before actually making the intercept.

This appears to violate the notion of a, presumably, CONTINUAL, right turn from the 292 heading to do the intercept.

My original question still stands…why not just just have the intercept occur from the 292 heading since we established from the outset of this interaction that the FMS can perform intercepts at right angles like this without any issue at all?

Even if it has to be coded as two separate lines (the climb to 2k then the intercept instruction), there isn’t a real need for the 2nd portion (the intercept) to utilize a 340 heading, nor does the chart call for it.

That’s the part I’m confused about and is the crux of my question. The result is not the same as how a pilot would typically elect to fly the procedure, knowing the FMS can perform the intercept from a 292 heading without issue using its turn anticipation. The 340 hdg doesn’t appear to be necessary.

Regards,
Keith

Hi again,
I can’t answer your “why it’s coding” in this way. The coding comes in this case from the FAA and is not a interpretation from us or the source provider sorry.

The codeing is a VI leg and this leg needs a heading for the intercept which much be differ to the R205/FRI … It’s a valid coding and the result is also correct. The coding standard is the same for every source provider but in most cases there are several coding solutions to reach the correct result.

Jeppesen goes this way …

Cheers
Richard

Thanks Richard,

That answers it, thank you. I was curious what the reason for the intermediate heading was, and also the source. If the source is the FAA then it certainly answers the question of whether it’s legal to fly the procedure that way. It appears “climbing right turn” has a lot more latitude than it initially appears and can, in fact, be a series of right turns rather than a single continuous turn to intercept the desired course.

Thank you again for the assistance.

Keith

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