Honest question...

In the 37/38 was there a seat that had to be occupied or could you fly solo from either seat?

I ask because in the T-34 the front seat had to be occupied. Soloing from the back seat was prohibited as the main circuit breaker panel and manual gear extension (and some other stuff) was only in the front seat.

So to play devil's advocate...if you are occupying the seat that is required but did not sign for the plane, are you SIC?