Originally Posted by
rickair7777
Yes, I think the regs would require an original signature. Flight instruction benefits from a high-degree of supervision. In that sort of situation I would have reviewed/endorsed it all the day before, included specific written Wx limitations in the endorsement, and had the student call me before he departed to discuss wx/notams.
There are some that say even that wouldn't be legal. Face to face same day as the flight.
Caveat Aviator.