Help Finding the Bug in a Custom IAP?

Navigation Data General MSFS Data
1

Hello,

Firstly - this is not a post dealing with any issues with Navigraph navdata. I’m purely looking for help understanding an issue I’m having coding an IAP, as a learning exercise for this stuff. I understand that’s not really what the forum here is for, so I understand if you don’t have time for this, but I’d surely appreciate any help or advice.

So - I’m building a real-world but non-public instrument approach to Juneau (PAJN); this is an RNP (AR) approach up the Gastineau channel to runway 26. It’s intended for use in the new PMDG navdata and I’m currently testing in the PMDG 777 (ultimately the procedure is intended for use in the 737 when it gets the new data format.) To my understanding this is the standard DFD navdata format?

The procedure appears as an approach in the FMC, and the SSR transition can be selected.
The lateral approach path works correctly all the way to the runway and out to the missed approach hold, including all RF legs. The problems are: no glidepath legs are drawn after the FAF (waypoint SIX in this table) so VNAV breaks there, and instead of a runway waypoint as I’ve intended to code it (RW26), the FMC displays the airport ID (PAJN).

I’ve obfuscated waypoint names and coords in the tables below; in my actual procedure they are sandard 5 character names. I’ve also hidden the coordinates. It’s not exactly top secret but since it is a proprietary procedure, I don’t want these things to be publicly searchable. Since the lateral path works, I assume the problem doesn’t lie here.

Below are two tables, one showing the entire procedure in the IAP table, and the other showing the waypoints as defined in the waypoints table. If anyone can spot any showstopping errors, I’d be really interested to learn anything you’d like to share.

If it helps and any of the gurus are interested, I’m happy to share the approach privately for you to try, I’m just trying to keep it not publicly searchable online.

Thanks for ANY input!

Column 1 Column 2 Column 3 Column 4 E F G H I J K L M N O P Q R S T U V W X Y Z AA AB AC AD AE AF AG AH AI AJ AK
area_code airport_identifier procedure_identifier route_type transition_identifier seqno waypoint_icao_code waypoint_identifier waypoint_latitude waypoint_longitude waypoint_description_code turn_direction rnp path_termination recommanded_navaid recommanded_navaid_latitude recommanded_navaid_longitude arc_radius theta rho magnetic_course route_distance_holding_distance_time distance_time altitude_description altitude1 altitude2 transition_altitude speed_limit_description speed_limit vertical_angle center_waypoint center_waypoint_latitude center_waypoint_longitude aircraft_category id recommanded_id center_id
CAN PAJN RNVM26 A SSR 10 PA SSR 58.17766111 -135.25886389 V C IF + 6000 18000 J tbl_vhfnavaids|PASSR
CAN PAJN RNVM26 A SSR 20 PA ONE xx.xx xx.xx E 1 TF + 6000 J tbl_terminal_waypoints|PAJNPAONE
CAN PAJN RNVM26 A SSR 30 PA TWO xx.xx xx.xx E 1 TF + 6000 J tbl_terminal_waypoints|PAJNPATWO
CAN PAJN RNVM26 A SSR 40 PA THREE xx.xx xx.xx E 1 TF + 5100 J tbl_terminal_waypoints|PAJNPATHREE
CAN PAJN RNVM26 A SSR 50 PA FOUR xx.xx xx.xx E L 1 RF 3.8 59.2 2.3 D + 5100 JNUOO 58.201845 -134.408606 J tbl_terminal_waypoints|PAJNPAFOUR tbl_terminal_waypoints|PAJNPAJUNOO
CAN PAJN RNVM26 A SSR 60 PA FIVE xx.xx xx.xx EE B L 1 RF 3.8 295 8.3 D + 3300 JNU01 58.201577 -134.409601 J tbl_terminal_waypoints|PAJNPAFIVE tbl_terminal_waypoints|PAJNPAJNU01
CAN PAJN RNVM26 R 10 PA FIVE xx.xx xx.xx E I 1 IF + 3300 18000 J tbl_terminal_waypoints|PAJNPAFIVE
CAN PAJN RNVM26 R 20 PA SIX xx.xx xx.xx E F 0.3 TF 292 2.5 D + 2500 J tbl_terminal_waypoints|PAJNPASIX
CAN PAJN RNVM26 R 30 PA SEVEN xx.xx xx.xx E 0.3 TF 292 2.2 D -3.5 J tbl_terminal_waypoints|PAJNPASEVEN
CAN PAJN RNVM26 R 40 PA EIGHT xx.xx xx.xx E R 0.3 RF 4.5 302 0.7 D -3.5 JNU02 58.356529 -134.343094 J tbl_terminal_waypoints|PAJNPAEIGHT tbl_terminal_waypoints|PAJNPAJNU02
CAN PAJN RNVM26 R 50 PA NINE xx.xx xx.xx E 0.3 TF 301 2.4 D - 160 -3.5 J tbl_terminal_waypoints|PAJNPANINE
CAN PAJN RNVM26 R 60 PA TEN xx.xx xx.xx E L 0.3 RF 1.3 267 0.8 D -3.5 JNU03 58.326674 -134.533437 J tbl_terminal_waypoints|PAJNPATEN tbl_terminal_waypoints|PAJNPAJNU03
CAN PAJN RNVM26 R 70 PA RW26 xx.xx xx.xx GY M 0.3 TF 264.8 0.96 D 73 -3.5 J tbl_runways|PAJNPARW26
CAN PAJN RNVM26 R 85 PA ELEVEN xx.xx xx.xx EYM 1 DF J tbl_terminal_waypoints|PAJNPAELEVEN
CAN PAJN RNVM26 R 90 PA SSR xx.xx xx.xx VY 1 TF + 6000 J tbl_vhfnavaids|PASSR
CAN PAJN RNVM26 R 95 PA SSR xx.xx xx.xx VE H R HM 70 4 D J tbl_vhfnavaids|PASSR
Column 1 Column 2 Column 3 Column 4 E F G H I
area_code region_code icao_code waypoint_identifier waypoint_name waypoint_type waypoint_latitude waypoint_longitude id
CAN PAJN PA ONE ONE W F xx.xx xx.xx PAJNPAONE
CAN PAJN PA TWO TWO W F xx.xx xx.xx PAJNPATWO
CAN PAJN PA THREE THREE W Z xx.xx xx.xx PAJNPATHREE
CAN PAJN PA FOUR FOUR W F xx.xx xx.xx PAJNPAFOUR
CAN PAJN PA FIVE FIVE WLF xx.xx xx.xx PAJNPAFIVE
CAN PAJN PA SIX SIX WAF xx.xx xx.xx PAJNPASIX
CAN PAJN PA SEVEN SEVEN WSF xx.xx xx.xx PAJNPASEVEN
CAN PAJN PA EIGHT EIGHT WSF xx.xx xx.xx PAJNPAEIGHT
CAN PAJN PA NINE NINE WSF xx.xx xx.xx PAJNPANINE
CAN PAJN PA TEN TEN WSF xx.xx xx.xx PAJNPATEN
CAN PAJN PA ELEVEN ELEVEN W F xx.xx xx.xx PAJNPAELEVEN
2

Hi again,
Before we continue please goto our development portal ans contact us under dev@navigraph.com and explain your company, project and your intention.

In general, it is not allowed to add/remove or change data or the structure from any navigational dataset, which we offer. Excluding, its for your personal usage only.

Thank you
Richard

3

Hi Richard,

The thing is, I’m no kind of dev. This is purely for my personal use. I’m a pilot for the airline that developed the procedures in question, and my kids enjoy flight simming and using it to see a bit of what I do at work. We’ve had fun creating approximations of my company’s RNPs in Southeast Alaska in the old PMDG navdata, and now the opportunity exists to try and make true 1:1 re-creations of them in the sim - for our use only. I couldn’t even freely share this work publicly without risking trouble at work; if I tried to sell it I’d surely be fired and probably sued. So you can rest assured that I won’t be sharing ANYTHING - my data or yours. This is just a fun project that at the same time is giving me a much deeper understanding of these procedures and this data than the airlines typically train us on, and I guess I’m enough of a nerd to be hooked ;).

I’m still glad to email that address if you’d like, but there’s not much to say, and I’m trying to be conscious of the fact that you’re running a business here and I don’t mean to distract from that. I just thought if you or someone else saw some obvious errors in my work and enjoyed talking about this stuff, you wouldn’t mind sharing a few pointers. I understand if it’s not something you have the time for though.

Thanks again…

4

Hi again,
Thanks for your clarification - fully understandable. I will contact you directly via PM to discuss your questions - but please give me a few days. I´m currently on vacation and such questions needs a little bit more time.

Hope thats a good solution for you - again, I will contact you directly :wink:
Have a nice day,
Richard

5

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