Originally Posted by
rudestuff
The US regulation is much more reasonable. If the student is rated on the aircraft (maybe doing commercial training or simulated instruments) then the instructor does not need a medical as the student is perfectly capable of and legal to fly with a dead body if necessary.
Agree on commercial training. However, you can't legally fly "under the hood" in USA unless the safety pilot (or instructor) is qualified to act as PIC and that requires a medical or basic med. Simulated instuments requires more than a "stiff" in the other seat.
One situation in which an instructor may give instruction with no medical is when giving a flight review to a pilot who is still current. Just don't put the applicant under the hood. Perhaps another is giving tail wheel instruction to a pilot who is qualified to fly nose wheel.