AD NUMBER: 2018-18-13

PRODUCT: All Boeing Model 737-100, -200, -200C, -300, -400, and -500 series airplanes.

ACTION: Final Rule.

SUMMARY: This AD was prompted by reports of cracking in certain flanges, and the adjacent web, of the wing outboard flap track at certain positions, and a determination that new inspections of certain flap track flanges and webs forward of the rear spar attachment are necessary.

This AD requires an inspection to determine the part number of the wing outboard flap track assembly; repetitive inspections of each affected wing outboard flap track for discrepancies, and applicable on-condition actions; and repetitive overhaul of each wing outboard flap track.

DATES: This AD is effective October 18, 2018.

COST: The FAA estimates that this AD affects 160 airplanes of U.S. registry. The cost of compliance is estimated as follows:

• Inspection (positions 1 and 8; Group 2 and Group 3, configuration 1) 78 work-hours × $85 per hour = $6,630 per cycle. Parts N/A. Total cost per airplane - $6,630 per cycle.
• Inspection (positions 1 and 8; Group 3, configuration 2) 89 work-hours × $85 per hour = $7,565 per cycle. Parts - N/A. Total cost per aircraft $7,565 per airplane per cycle.
• Inspection (positions 2 and 7; Group 2 and Group 3, configuration 1) 83 work-hours × $85 per hour = $7,055 per
• cycle. Parts N/A. Total cost per airplane per cycle $7,055.
• Inspection (positions 2 and 7; Group 3, configuration 2) 86 work-hours × $85 per hour = $7,310 per airplane per cycle. Parts N/A. Total cost per airplane per cycle $7,310.

FMI: AD