Originally posted by PJ2 ...
To my knowledge, the notion of sleep inertia on the part of the PF has not been widely discussed but the UAS event occurred within about ten minutes of the call to the flight rest where he was sleeping.
It was the PNF who said he had dozed and returned to the cockpit at about 0200 and took the LHS. The PF had been in the RHS from departure Rio de Janeiro. Your comment regarding
sleep inertia is still relevant as it could well explain the PNF's lack of positive action over the next few minutes.