Narrative:

Pushing back from gate at cun. Just finished starting engine #3. Flight attendant opened cockpit door and said there was smoke in the aft of the cabin. Stopped push, flight engineer opened cockpit door and saw passenger coming forward from aft of aircraft. Could smell acidic smoke when door opened. Flight attendants said it was getting worse. Emergency ground evacuate/evacuation initiated. Ground was notified. Fire rescue on scene very quickly. Evacuate/evacuation went as normal as can be expected.

Google
 

Original NASA ASRS Text

Title: B727 EVACS PAX AS ACRID SMOKE CONTINUES TO FILL CABIN AFTER ENG START AT CUN.

Narrative: PUSHING BACK FROM GATE AT CUN. JUST FINISHED STARTING ENG #3. FLT ATTENDANT OPENED COCKPIT DOOR AND SAID THERE WAS SMOKE IN THE AFT OF THE CABIN. STOPPED PUSH, FE OPENED COCKPIT DOOR AND SAW PAX COMING FORWARD FROM AFT OF ACFT. COULD SMELL ACIDIC SMOKE WHEN DOOR OPENED. FLT ATTENDANTS SAID IT WAS GETTING WORSE. EMER GND EVAC INITIATED. GND WAS NOTIFIED. FIRE RESCUE ON SCENE VERY QUICKLY. EVAC WENT AS NORMAL AS CAN BE EXPECTED.

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.