SEQ button function?

[SharpeXB]

From p119 in the manual referring to the HSI MFD button:
SEQ # Option. When selected and boxed, all waypoints of the sequence are displayed on the HSI and dashed lines connect them in sequence. Successive presses of this button cycle through the sequences. The F/A-18C can store three sequences. See Waypoint Navigation.

What are these sequences? I notice they seem to interfere with selecting Markpoints, do they?

Edited June 10 by SharpeXB

[Tholozor]

Think of Sequences like routes. If you're familiar with the F-16's steerpoint allocations, it's like steerpoints 1 through 20 for the navigation route. With the Hornet, however, you can create three different routes using any waypoints in any order.

When a sequence is boxed, the avionics assumes the intention is to navigate to those waypoints (possibly automatically and/or if coupled steering is desired). Since the Hornet has no way to edit waypoints in the cockpit without first selecting them for command steering, the only waypoints that can be scrolled through when a sequence is boxed are the ones inside that specific sequence, otherwise you could end up inadvertently steering to a waypoint outside the desired sequence.

Regarding markpoints, those exist outside the standard 60 waypoint (0 through 59) allocation, and therefore cannot be selected when a sequence is boxed.

Edited June 10 by Tholozor

[SharpeXB]

48 minutes ago, Tholozor said:

the only waypoints that can be scrolled through when a sequence is boxed are the ones inside that specific sequence, otherwise you could end up inadvertently steering to a waypoint outside the desired sequence.

That would explain why I can’t scroll to a Markpoint when SEQ is boxed, right?

I haven’t tried creating different routes so in that case pressing the SEQ button shouldn’t do anything? Except it makes the route disappear and then I guess I need to press it two more times to show it again. It seemed random but I get it now. Thanks. 

[Tholozor]

Correct. When you press the SEQ option on the HSI, it goes from SEQ1 to [SEQ1] (boxed), then the same for SEQ2 and 3, then back to SEQ1 on a loop. Doesn't matter if a sequence is empty, pressing that button will always cycle through sequences, as that's also how you select a sequence for programming.

Edited June 10 by Tholozor