Note: As per the latest EASA syllabus, no questions address this learning objective. However, they are still part of the UK CAA syllabus, as also confirmed by recent feedback.

Time to PSR (Point of Safe Return):
The Point of Safe Return (PSR) is the last point on a route at which it is possible to return to the departure airfield arriving back with the required fuel reserves still available in the tanks. Continuing passed the PSR you are now committed to landing at your destination.

Time (to PSR) = E x H / (O + H)

• Where E = Safe Endurance based on available fuel; H = Ground speed Home and O = Ground speed Out.

Note: Safe endurance is used as it ensures that the required reserves remain intact.