While below 👇 probably doesn’t apply to HK coming back to base, for anyone else following, a change last year clarified even the first leg of a rotation (normally triggering 23K), if changed from operating to dh or vice versa, triggers RR pay.

MOU 24-01:
Operating to Deadheading:
Prior to the airborne departure of the first flight segment of a pilot’s rotation, that rotation may be changed from the pilot operating a single flight segment, to deadheading on that same flight segment. If this occurs, the pilot will be paid as though they have been rerouted on that flight segment.
• If an actual reroute occurs in a duty period prior to the duty period in which this change occurs, the pilot will receive single pay, no credit for the changed flight segment, in addition to any other pay for the rotation.
• If not, the pilot will receive one-half pay, no credit for the changed flight segment, in addition to any other pay for the rotation, and any reroutes that occur in subsequent duty periods will result in single pay, and credit in addition to any other pay for the rotation.

—-

Deadheading to Operating:
Prior to the airborne departure of the first flight segment of a pilot’s rotation, if the Company desires to change a single flight segment on a rotation from the pilot deadheading to operating that same flight segment, they may do so only as a proffer to the pilot. If the pilot accepts the proffer, they will receive single pay, no credit for the changed flight segment, in addition to any other pay for the rotation. If the pilot declines the proffer, they will remain on the originally scheduled deadhead, unless the Company chooses to remove the pilot from all or a portion of their rotation under Section 4 E. 1. of the PWA.

Also, assuming the pilot accepts the proffer, any later reroutes in the same rotation, whether occurring in a prior, subsequent, or the same duty period, will each generate an additional single pay, no credit for the affected leg(s), in addition to any other pay for the rotation.