Missing Approaches

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   I just earned my instrument rating (rah rah), and I'm confused about something. If I'm flying to KDLS (The Dalles, OR), and I go to enter a procedure the only option I get is the RNAV-GPS A. KDLS has an LDA/DME 25, but the IFD 540 does not present this as an option. I have an "Americas" Navdata subscription from Jepp. Is it a problem on the data side? Or the IFD?

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Tor Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 20 Mar 2020 Location: Hood River, OR Status: Offline Points: 4	Post Options Post Reply Quote Tor Report Post Thanks(0) Quote Reply Topic: Missing Approaches Posted: 14 May 2020 at 8:52pm
	I just earned my instrument rating (rah rah), and I'm confused about something. If I'm flying to KDLS (The Dalles, OR), and I go to enter a procedure the only option I get is the RNAV-GPS A. KDLS has an LDA/DME 25, but the IFD 540 does not present this as an option. I have an "Americas" Navdata subscription from Jepp. Is it a problem on the data side? Or the IFD?

AviSteve Members Profile Send Private Message Find Members Posts Add to Buddy List Admin Group Joined: 12 Feb 2018 Location: Melbourne, FL Status: Offline Points: 2314	Post Options Post Reply Quote AviSteve Report Post Thanks(0) Quote Reply Posted: 14 May 2020 at 9:14pm
	That approach is not in the database that we receive from Jeppesen. There are specific rules regarding how approaches get coded into the database. Often, an approach will have some characteristic that renders it uncodeable. I'll check with Jeppesen to see why this approach isn't there.
	Steve Lindsley Avidyne Engineering

Tor Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 20 Mar 2020 Location: Hood River, OR Status: Offline Points: 4	Post Options Post Reply Quote Tor Report Post Thanks(0) Quote Reply Posted: 15 May 2020 at 6:13pm
	What is super strange is that, around a month ago, when I had an older set of navdata active on the IFD 540, the LDA approach showed up. I shot it under the hood! But the RNAV approach did NOT show up in the procedures for the airport. So, now the situation is flipped with the current navdata. I'm glad, because I'd rather have the RNAV if I only get one procedure. But talk about bizarre.

AviSteve Members Profile Send Private Message Find Members Posts Add to Buddy List Admin Group Joined: 12 Feb 2018 Location: Melbourne, FL Status: Offline Points: 2314	Post Options Post Reply Quote AviSteve Report Post Thanks(0) Quote Reply Posted: 16 May 2020 at 11:52am
	As I suspected... Here's the response from Jeppesen. The LDA DME Rwy 25 approach at KDLS is unusual because it requires a glideslope to fly the procedure (see in the chart minimums box "LDA with GS" is the only option). The vast majority of LDA approaches do not require glideslope - there are very few of these procedures in existence worldwide. Consequently, ARINC 424 coding rules make no provision for coding an LDA w/glideslope. Since the procedure requires glideslope and ARINC does not support LDA procedure type with glideslope, these procedures are not codeable.
	Steve Lindsley Avidyne Engineering

Tor Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 20 Mar 2020 Location: Hood River, OR Status: Offline Points: 4	Post Options Post Reply Quote Tor Report Post Thanks(0) Quote Reply Posted: 16 May 2020 at 10:10pm
	Cool, thank you for the follow up. I think when I flew the approach, I was just flying the approach using the chart on my ipad and tuned in the frequency, etc. But I do recall a few months back NOT finding the RNAV A in the IFD 540, so I'm glad they added that one in.