How many instructors in a plane does it take to block a runway? Two.
Practicing take offs and landings in the Bonanza, flying for the first time from the right hand seat, it was coming together. Perhaps because I have less to unlearn in the Bonanza, I immediately felt comfortable flying from the "wrong" side. But, as with most Bonanzas, it is really configured for single pilot flying. And he/she has to to fly from the left side.
With a dual yoke installed, the right side pilot still has no brakes, and no access to the fuel selector, which is on the floor by the left seat pilot's left foot. And he or she has to reach across alongside the left seat pilot's right leg to adjust the trim.
So that set the scene. After 45 minutes, we needed to switch fuel tanks, and at first we were going to do that on the downwind leg. To make it safer, we decided that Instructor Anne would change the tanks when we were stopped on the runway after practicing a short field landing at McKinney (TKI). Which she did, reaching down with her left hand. But she overshot the stop and accidentally shut off the fuel completely, shutting down the engine. I sure am glad we agreed that the tank switch should be delayed until we were on the ground!
We tried a couple of hurried restarts while the tower told the other aircraft in the pattern to go around, which didn't work until I noticed that the fuel pressure was zero. Then IA realized what she had done, selected the best tank, and and we were able to get it going again. So how many CFI's does it take to block the runway? Yes, both of us.