S-76: yours is a reall nice helo, from what I've read.
Anyway, in the book "Chickenhawk", the author said that during helicopter assault landings (Hueys), the second pilot closely backed up the first pilot on the controls, in case the flying pilot were hit by an enemy AK-47 (or larger caliber...).
This is an extreme and very unique example of back-up. In transports we fly a coupled approach (on autopilot) for a Cat 2, once a year in the simulator, and the Captain takes control (if required approach lights are in sight at 100') by tapping the back of the FO's hand with his/her hand, saying "I have the airplane".
In anesthesiology, do numerous complex procedures overlap each other, with an overall very standard sequence desired, when things are going well? I wish I could have thanked everyone after my h----oid surgery (first surgery, ever)! I was like this beforehand, just not so obvious...