The Bonanza/ Baron crowd loses one to two aircraft a year due to the passenger door opening on takeoff. It is startling and is noisy but results in no aerodynamic problem for the aircraft. Unfortunately, some pilots do not know that, freak out and lose control of the airplane trying to close the door. Remember, fly the airplane.

Jeff,

 

Flying solo I once had the Skymaster copilot-side clam-shell upper door pop open on me during takeoff, locking the over center link that required at least two hands to crack the link and close the door - Any way, the event certainly woke me up!  Every chart that was on the copilot seat left the airplane, the wind noise was so great that even the Bose headset could not overcome it.  Not having my head about me, I failed to turn up the volume to at least try and hear the tower - So.. after reaching almost pattern altitude and starting the crosswind turn, I said I had an emergency, the door was open and I couldn't hear,  I was transmitting in the blind (tower freq) and I was returning to land NOW.  I slowed the plane to avoid putting too much stress on the door (may have been a mistake since the AOA of the door was increased), landed uneventfully, thanked the tower, closed and LATCHED the door in the run-up area and departed more alert than ever.

 

Just one more of the many times the good angel overpowered the stunt the bad angel initiated.