What was found
INSPECTION TYPE:N/A, CLIMBING THRU FL260 AT 320 KIAS A SUDDEN DEAFENING NOISE ACCOMPANIED BY CONSIDERABLE VIBRATION STARTED. SLOWING TO 200 KTS REDUCED THE NOISE AND VIBRATION TO TOLERABLE INTENSITY. NO PRESSURIZATION PROBLEMS WERE NOTED. VISUAL INSP THRU NOSE W/W VIEW PORT SHOWED ONLY MORE LIGHT THAN NORMAL. CONCLUSION WAS AN OPEN NLG DOOR. REMOVED AND REPLACED BROKEN NLG DOOR OPERATING MECHANISM AND UPPER RETRACT ROD ASSY PER M/M 32-22-02. P/N 5640832-5, S/N ON UP16210, S/N OFF NSN P/N 3646504, S/N ON TAG 906792, S/N OFF NSN. CK''''D PER M/M 32-22-01. JACKED AND SWUNG NOSE GEAR, OK.