OBS and Sequencing

Friends -

I was flying with my CFII today. We had an IFR approach loaded in the IFD540, and it was active.

My instructor then said to go into OBS mode and fly to a specific fix, and hold on a radial. So I switched to OBS made, dialed in the radial, and navigated to the fix. Before I could enter the hold, however, the IFD sequenced back to the next leg in the loaded IFR approach. I read the Pilots Guide and the Bauer book, and it seems that this is normal behavior. So, these are my questions...

1. Am I correct...is what I've described the normal way the IFD handles this scenario?

2. Is there any way to disable this functionality?

3. Assuming there's no way to disable this functionality, how would I handle this request from my CFII? In other words, with an IFR approach already loaded, is there any way to go into OBS mode and then hold at a fix (for an indeterminate time) before the IFD sequences to the next leg in the IFR approach?

Thanks everyone!

The IFD has robust Hold capability, which should always be used when a Hold is needed.  If the instructor wants you to undertake a hold manually, he/she should use raw VOR data.  OBS function is part of the flight plan so automatic sequencing is appropriate.  It is a course to or from a FP waypoint.  The Hold should be entered as the next waypoint in the FP.  The only time OBS mode won’t sequence is if the OBS course doesn’t cross a FP leg or waypoint.

It’s my understanding that GTN units in OBS mode don’t auto sequence, which may be setting an expectation for your instructor.

There are lots of ways to teach the functionality of OBS mode.  However, trying to force the IFD to behave in a manner that is incompatible with real world methods is not one of them.  Teaching holds using OBS mode has no practical application.  Teaching Holds using raw VOR data is an important skill to impart.