The main cabin door came open on taxi out on an air carrier mdt.

Attributes
ACN	224502
Time
Date	199210
Day	Thu
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : iah
State Reference	TX
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Dusk
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Medium Transport, High Wing, 2 Turboprop Eng
Flight Phase	ground other : taxi
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 250 flight time total : 3300 flight time type : 2000
ASRS Report	224502
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : critical non adherence : published procedure other anomaly other
Independent Detector	other flight crewa other other : unspecified
Resolutory Action	none taken : detected after the fact
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation other

Narrative:

The aircraft had been closed up and we had completed the after start checklist when we were told we had a 'runner' and we would board one more passenger. After the flight attendant informed us the passenger was seated and she was ready, we began taxiing. After completing the taxi checklist, the captain asked me to start engine one. Upon completion of the start, I glanced at the overhead panel and noticed the cabin door light was on and informed the captain. At approximately the same time the flight attendant called us and informed us the door had come open and hit the ground. We asked her to close the door and informed ground control we were returning to the gate. Maintenance checked the door and released us. I believe the error occurred because of complacency and not rerunning the before start checklist after boarding the additional passenger.

Original NASA ASRS Text

Title: THE MAIN CABIN DOOR CAME OPEN ON TAXI OUT ON AN ACR MDT.

Narrative: THE ACFT HAD BEEN CLOSED UP AND WE HAD COMPLETED THE AFTER START CHKLIST WHEN WE WERE TOLD WE HAD A 'RUNNER' AND WE WOULD BOARD ONE MORE PAX. AFTER THE FLT ATTENDANT INFORMED US THE PAX WAS SEATED AND SHE WAS READY, WE BEGAN TAXIING. AFTER COMPLETING THE TAXI CHKLIST, THE CAPT ASKED ME TO START ENG ONE. UPON COMPLETION OF THE START, I GLANCED AT THE OVERHEAD PANEL AND NOTICED THE CABIN DOOR LIGHT WAS ON AND INFORMED THE CAPT. AT APPROX THE SAME TIME THE FLT ATTENDANT CALLED US AND INFORMED US THE DOOR HAD COME OPEN AND HIT THE GND. WE ASKED HER TO CLOSE THE DOOR AND INFORMED GND CTL WE WERE RETURNING TO THE GATE. MAINT CHKED THE DOOR AND RELEASED US. I BELIEVE THE ERROR OCCURRED BECAUSE OF COMPLACENCY AND NOT RERUNNING THE BEFORE START CHKLIST AFTER BOARDING THE ADDITIONAL PAX.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.