AD NUMBER: 2018-07-04

PRODUCT: All Boeing Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), and DC-9-87 (MD-87) airplanes, Model MD-88 airplanes, and Model MD-90-30 airplanes.

ACTION: Final Rule.

SUMMARY: This AD was prompted by a report of loss of airspeed indication due to icing.

This AD requires modifying the air data heat (ADH) system.

DATES: This AD is effective September 10, 2018.

COST: The FAA estimates that this AD affects 553 airplanes of U.S. registry. The costs of compliance are estimated as follows:

• Modification, MD-80 Group 1, 84 airplanes. Labor 56 work-hours × $85 per hour = $4,760. Parts $4,459. Total cost per aircraft $9,219.
• Modification, MD-80 Group 2, 11 airplanes. Labor 57 work-hours × $85 per hour = $4,845. Parts $11,014. Total cost per aircraft $15,859.
• Modification, MD-80 Group 3, 336 airplanes. Labor 57 work-hours × $85 per hour = $4,845. Parts $8,589 Total cost per aircraft $13,434.
• Modification, MD-80 Group 4, 1 airplane. Labor 56 work-hours × $85 per hour = $4,760. Parts $4,479. Total cost per aircraft $9,239
• Modification, MD-80 Group 5, 37 airplanes. Labor 57 work-hours × $85 per hour = $4,845. Parts $11,034 Total cost per aircraft $15,879.
• Modification, MD-90 Group 1, 84 airplanes. Labor 37 work-hours × $85 per hour = $3,145. Parts $4,395.  Total cost per aircraft $7,540.

FMI: AD