What was found
THE NLG COLLAPSED DURING PUSHBACK FROM HANGAR IN EWR. INITIAL EXAMINATION OF THE GEAR REVEALED THAT THE OVER-CENTER LINK AND DRAG BRACE HAD FAILED AND THERE WAS DAMAGE TO THE NLG DOORS. THE AIRCRAFT WAS TAKEN OUT OF SERVICE FOR REPAIR. A DETAILED INVESTIGATION WILL BE CONDUCTED BY ENGINEERING TO DETERMINE THE PRIMARY CAUSE OF FAILURE AND TO IDENTIFY THE RESPONSIBLE PART. [07-25-07] LAB CONFIRMED THE INITIAL FAILURE OF THE OVER-CENTER LINK RESULTED IN THE NLG COLLAPSE.