IFD 5 Series & IFD 4 Series Touch Screen GPS/NAV/COM

Direct To

Printed From: Avidyne
Category: Avidyne General
Forum Name: IFD 5 Series & IFD 4 Series Touch Screen GPS/NAV/COM
Forum Description: Topics on Avidyne's IFD 5 Series and IFD 4 Series Touch Screen GPS/NAV/COM
URL: http://forums.avidyne.com/forum_posts.asp?TID=1923
Printed Date: 24 Apr 2024 at 7:41am
Software Version: Web Wiz Forums 12.01 - http://www.webwizforums.com

Topic: Direct To

Posted By: teeth6
Subject: Direct To
Date Posted: 06 Jan 2020 at 6:23pm

I noticed a behavior on the IFD which I’d like an explanation of. I see the same behavior on the simulator and there must be a logical explanation.

I was on a flight plan to SFZ and on vectors for the GPS 5 approach. The approach was activated and then I was told “approach clearance cancelled,” proceed direct FOSTY and hold as published. FOSTY is where the hold is on the missed approach and was listed in the plan so I highlighted FOSTY and hit direct to but instead of of FOSTY coming up to accept the airport SFZ came up. I thought maybe I highlighted the airport by mistake so I again selected FOSTY with the same result.

I ended up just inserting a new waypoint FOSTY prior to where the approach began and hit direct to which worked, but I’m wondering why the IFD kept changing my selected waypoint in this scenario.

Replies:

Posted By: dmtidler
Date Posted: 06 Jan 2020 at 8:05pm

From page 1-36 & 1-37 of the latest IFD500 Series Pilot Guide:

If a different waypoint is desired, there are a number of ways in which the proper waypoint can be entered in that Direct-To dialog box:

Twist the outer ring of the bottom right IFD knob to scroll up/down through a flight plan list that re-populates the waypoint in the dialog box from the active FMS flight plan (Note that the Missed Approach must be activated to use this technique for points in the published missed approach). When the desired waypoint is displayed, press the knob in to accept;

It appears what you experienced is the way it was designed. Operationally, it appears that if you have Auto Enable Missed - On in the current user settings, a direct-to any fixed point in the missed approach procedure may be accomplished after crossing the FAF. With Auto Enable Missed - Off in the current user settings, a direct-to any fixed point in the missed approach may be accomplished after selecting Enable Missed (which will be available at LSK 4 after crossing the FAF).

Posted By: teeth6
Date Posted: 06 Jan 2020 at 8:52pm

Thanks. I figured it was behaving as designed and reading that explanation makes sense. I didn’t realize the the missed approach procedure had to be active to go direct to the waypoint.

Posted By: chflyer
Date Posted: 07 Jan 2020 at 4:54am

Thanks Darren. Very useful response, especially the operational implication of Auto Enable Missed setting in this case!

-------------
Vince

Posted By: dmtidler
Date Posted: 07 Jan 2020 at 11:38pm

Three more observations regarding direct-to missed approach waypoints:

It appears the missed approach must be either activated or enabled to allow a direct-to a missed approach waypoint (the PM indicated the missed approach needs to be activated to allow this direct-to operation)

If missed approaches are set to automatically enable in the current user settings and you wish to proceed to a waypoint on the missed approach prior to crossing the FAF; activating a leg beyond the FAF (i.e. the leg to the MAP) appears to instantly enable the missed approach and thus allows selecting a direct-to a missed approach waypoint on the the active approach.

If the missed approaches are not set to automatically enable in the current user settings and you wish to proceed to a waypoint on the missed approach prior to crossing the FAF; first activate a leg beyond the FAF (i.e. the leg to the MAP), then select Enable Missed (LSK 4L), finally perform a direct-to a missed approach waypoint on the active approach.