** Like Tom said, the crewchief liked to sit behind the A/C so that they could get a good swing at the A/C's head if he needed to. **
Also, Dave, all kidding aside, from the left side the crew chief could look between the pilots and see the master caution light, the fuel gauge, and the main rotor torque thingee.
I used to get real nervous sometimes when I couldn't see them from t'other side. Seeing the pounds of fuel left was real important when loading and mentally figgering weight & balance, as in, "I wonder how many of these sorry so-n-so's we can lift outta here without balling this ship up like we did the last one...?"
Plus, I could see all of our lucky charms from there. The crucifix, the rabbit's foot, the St. Christopher's medal, the sea glass, the mezzuzah, the scapular, the lucky gator ...
Bob