What happened
NTSB summary, verbatimThe pilot stated that the aircraft had been performing normally during the flight to Jamaica, West Indies, except for with a slight vibration during the initial flight. During the return leg to Chicago, Illinois, the captain he said that the airplane started vibrating " ten times as bad", so he diverted to, and affected an otherwise uneventful landing, in Miami, Florida. He added that the vibration had continued throughout the flight, until "flaps five" was set during the approach, at which time the vibration stopped. After landing, examination of the airplane showed that about a 24-inch section of the right elevator trim tab had been missing from the aircraft. In addition to the examination of the elevator, the remaining parts adjacent to the separated tab to include two control rods with rod ends, one hinge fitting from the right hand elevator rear spar were removed and examined. The examination revealed the presence of fractures, wear marks to the control rod, as well as post fracture damage to the rods. In addition, the hinge fitting had also incurred fractures as well as severe post fracture rubbing to the lugs, and worn areas between the hinge lugs and the inboard and outboard surfaces of unfractured lugs. On the elevator, rubbing was noted in areas on the aft face and lower skin panels of the elevator rear spar. In addition, the rear spar reinforcing angle and elevator tab control rod inner fairing and external mast fitting had incurred also damage. Boeing reports documenting examinations of the remaining damaged portions of elevator and tab assembly have been included with this report. Pertinent maintenance records were not obtained from Ryan International Airlines or Aer Lingus PLC, and there was no evidence of compliance with Boeing's system maintenance program (SB 737-55A1070R1), pertinent to "freeplay" checks.
Photographs
1the aircraft, and what the investigators foundProbable cause
the Board's determinationInadequate maintenance by company maintenance personnel and failure to comply with manufacturer recommended maintence procedures (SB 737-55A1070R1), which resulted in an inflight inseparation of a section of the airplane's right hand elevator control tab. A factor in the incident was the flight crew's continued operation of the airplane with a known deficiency.
NTSB analysis
from the final reportThe pilot stated that the aircraft had been performing normally during the flight to Jamaica, West Indies, except for with a slight vibration during the initial flight. During the return leg to Chicago, Illinois, the captain he said that the airplane started vibrating " ten times as bad", so he diverted to, and affected an otherwise uneventful landing, in Miami, Florida. He added that the vibration had continued throughout the flight, until "flaps five" was set during the approach, at which time the vibration stopped. After landing, examination of the airplane showed that about a 24-inch section of the right elevator trim tab had been missing from the aircraft. In addition to the examination of the elevator, the remaining parts adjacent to the separated tab to include two control rods with rod ends, one hinge fitting from the right hand elevator rear spar were removed and examined. The examination revealed the presence of fractures, wear marks to the control rod, as well as post fracture damage to the rods. In addition, the hinge fitting had also incurred fractures as well as severe post fracture rubbing to the lugs, and worn areas between the hinge lugs and the inboard and outboard surfaces of unfractured lugs. On the elevator, rubbing was noted in areas on the aft face and lower skin panels of the elevator rear spar. In addition, the rear spar reinforcing angle and elevator tab control rod inner fairing and external mast fitting had incurred also damage. Boeing reports documenting examinations of the remaining damaged portions of elevator and tab assembly have been included with this report. Pertinent maintenance records were not obtained from Ryan International Airlines or Aer Lingus PLC, and there was no evidence of compliance with Boeing's system maintenance program (SB 737-55A1070R1), pertinent to "freeplay" checks.