AD 2018-20-12

This AD is effective November 23, 2018.

The Director of the Federal Register approved the incorporation by reference of certain publications listed in this AD as of November 23, 2018.

For service information identified in this final rule, contact Bombardier, Inc., Q-Series Technical Help Desk, 123 Garratt Boulevard, Toronto, Ontario M3K 1Y5, Canada; telephone 416-375-4000; fax 416-375-4539; email thd.qseries@aero.bombardier.com; internet http://www.bombardier.com. You may view this service information at the FAA, Transport Standards Branch, 2200 South 216th St., Des Moines, WA. For information on the availability of this material at the FAA, call 206-231-3195. It is also available on the internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2018-0553.

John P. DeLuca, Aerospace Engineer, Avionics and Administrative Services Section, FAA, New York ACO Branch, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 516-228-7369; fax 516-794-5531; email 9-avs-nyaco-cos@faa.gov.

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to certain Bombardier, Inc., Model DHC-8-102, -103, and -106 airplanes, Model DHC-8-200 series airplanes, and Model DHC-8-300 series airplanes. The NPRM published in the Federal Register on July 6, 2018 (83 FR 31493). The NPRM was prompted by reports of arcing and smoke emanating from the windshield, caused by loose or damaged windshield heater terminal lugs. The NPRM proposed to require revising the maintenance or inspection program to incorporate MRB tasks for general visual inspections of the windshield moisture seal. The NPRM also proposed to require re-torqueing the windshield heater terminal lugs, applying a coating to the windshield heater screw heads, doing a chemical cleaning of the wiring and components, doing a visual inspection of the wiring and components, doing an operational test of the pilot's and co-pilot's windshield heating system, and repair if necessary.

We are issuing this AD to address loose terminal lugs and terminal lugs damaged due to fluid ingress between the windshields and side window posts, which could lead to burning of the lugs and cracking of the windshields, and could ultimately cause a loss of cabin pressure, resulting in an emergency descent.

Transport Canada Civil Aviation (TCCA), which is the aviation authority for Canada, has issued Canadian AD CF-2017-25, dated July 31, 2017 (referred to after this as the Mandatory Continuing Airworthiness Information, or “the MCAI”), to correct an unsafe condition for certain Bombardier, Inc., Model DHC-8-102, -103, and -106 airplanes, Model DHC-8-200 series airplanes, and Model DHC-8-300 series airplanes. The MCAI states:

There have been several reports of arcing and smoke emanating from the windshields. Investigation of these incidents revealed that de-icing fluid and water could enter between the windshields and side window posts, leading to possible damage of the windshield heater terminal lugs creating arcing and smoke. In addition, investigation also revealed that the windshield heater terminal lugs tend to loosen over time. Loose terminal lugs could also have a similar effect of arcing and smoke. Both events could lead to burning of the lugs and, due to the excessive heat, cracking of the windshields. If not corrected, these conditions could cause a loss of cabin pressure resulting in an emergency descent.

You may examine the MCAI in the AD docket on the internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2018-0553.

We gave the public the opportunity to participate in developing this final rule. We have considered the comment received. The Air Line Pilots Association, International (ALPA) indicated its support for the NPRM.

We reviewed the relevant data, considered the comment received, and determined that air safety and the public interest require adopting this final rule as proposed, except for minor editorial changes. We have determined that these minor changes:

• Are consistent with the intent that was proposed in the NPRM for addressing the unsafe condition; and

• Do not add any additional burden upon the public than was already proposed in the NPRM.

Bombardier has issued Service Bulletin 8-30-41, Revision A, dated March 24, 2017. This service information describes procedures for re-torqueing the windshield heater terminal lugs and applying Humiseal coating to the screw heads of the windshield heater, doing a chemical cleaning and general visual inspection of the wiring and components, and doing an operational test of the windshield heating system.

Bombardier has also issued the following service information, which describes airworthiness limitation tasks for a general visual inspection of the windshield moisture seal. These documents are distinct since they apply to different airplane models.

• de Havilland Inc. Dash 8 Series 100 Maintenance Task Card Task Number 5610/01, “General Visual Inspection of the Windshield Moisture Seal,” dated August 5, 2017.

• de Havilland Inc. Dash 8 Series 200 Maintenance Task Card Task Number 5610/01, “General Visual Inspection of the Windshield Moisture Seal,” dated August 5, 2017.

• de Havilland Inc. Dash 8 Series 300 Maintenance Task Card Task Number 5610/01, “General Visual Inspection of the Windshield Moisture Seal,” dated March 15, 2017.

This service information is reasonably available because the interested parties have access to it through their normal course of business or by the means identified in the ADDRESSES section.

We estimate that this AD affects 63 airplanes of U.S. registry.

We estimate the following costs to comply with this AD:

We have determined that revising the maintenance or inspection program takes an average of 90 work-hours per operator, although we recognize that this number may vary from operator to operator. In the past, we have estimated that this action takes 1 work-hour per airplane. Since operators incorporate maintenance or inspection program changes for their affected fleet(s), we have determined that a per-operator estimate is more accurate than a per-airplane estimate. Therefore, we estimate the total cost per operator to be $7,650 (90 work-hours × $85 per work-hour).

We have received no definitive data that would enable us to provide cost estimates for the on-condition actions specified in this AD.

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. Subtitle VII: Aviation Programs, describes in more detail the scope of the Agency's authority.

We are issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701: “General requirements.” Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

This AD is issued in accordance with authority delegated by the Executive Director, Aircraft Certification Service, as authorized by FAA Order 8000.51C. In accordance with that order, issuance of ADs is normally a function of the Compliance and Airworthiness Division, but during this transition period, the Executive Director has delegated the authority to issue ADs applicable to transport category airplanes and associated appliances to the Director of the System Oversight Division.

This AD will not have federalism implications under Executive Order 13132. This AD will not have a substantial direct effect on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government.

For the reasons discussed above, I certify that this AD:

(1) Is not a “significant regulatory action” under Executive Order 12866,

(2) Is not a “significant rule” under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979),

(3) Will not affect intrastate aviation in Alaska, and

(4) Will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows:

1. The authority citation for part 39 continues to read as follows:

2. The FAA amends § 39.13 by adding the following new airworthiness directive (AD):