Discussion
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-8-300 series airplanes. The NPRM published in the Federal
Register on July 6, 2018 (83 FR 31496). The NPRM was prompted by
reports indicating that a certain emergency exit door could not be
opened during maintenance. The NPRM proposed to require a detailed
inspection of the ball bearings of an emergency exit, replacement of
bearings if necessary, application of CIC, and revision of the
maintenance or inspection program, as applicable.
We are issuing this AD to address corrosion of the emergency exit
door ball bearings, which could result in the inability to open the
emergency exit door during an emergency evacuation and consequently
impede airplane egress.
Transport Canada Civil Aviation (TCCA), which is the aviation
authority for Canada, has issued Canadian Airworthiness Directive CF-
2017-30, dated August 30, 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-8-300 series
airplanes. The MCAI states:
An operator has reported the inability to open the Forward Right
Hand Type I emergency exit door with either the internal or external
handle during maintenance. Investigation has determined that the
handle was found to be jammed due to corroded center and lower shaft
ball bearings. Condensation has been found to be the root cause of
the Forward Right Hand Type I emergency exit door hardware
corrosion. Other Forward Right Hand Type I emergency exit door ball
bearings are also susceptible to corrosion. Inability to open the
Forward Right Hand Type I emergency exit door during an emergency
evacuation may impede aircraftegress.
This [Canadian] AD mandates the inspection for corrosion and
replacement, as required, of all Forward Right Hand Type I emergency
exit door ball bearings, and the application of corrosion inhibiting
compound (CIC), to ensure that the Forward Right Hand Type I
emergency exit door can be opened when required.
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-
0586.
Comments
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.
Conclusion
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.
Related Service Information Under 1 CFR Part 51
Bombardier has issued the following service information:
Service Bulletin 8-52-65, dated July 26, 2017, which
describes procedures for a detailed inspection of the forward right-
hand type I emergency exit door ball bearings for corrosion, seal
damage, and loss of lubricant; applying CIC; and replacing emergency
exit door ball bearings if necessary.
de Havilland Inc. Dash 8 Series 300 MaintenanceTask Card
Task Number 5220/12 (``Servicing of Forward RH Emergency Exit
Mechanisms''), dated March 15, 2017, which describes procedures for
servicing the forward right-hand emergency exit door mechanisms.Temporary Revision (TR) 54-042, dated April 10, 2018, to
the DHC-8-300 Aircraft Maintenance Manual (AMM), which describes
procedures for servicing the type I emergency exit door mechanisms.
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.
[[Page 52755]]
Costs of Compliance
We estimate that this AD affects 16 airplanes of U.S. registry.
We estimate the following costs to comply with this AD:
Estimated Costs for Required Actions
----------------------------------------------------------------------------------------------------------------
Cost per Cost on U.S.
Labor cost Parts cost product operators
----------------------------------------------------------------------------------------------------------------
3 work-hours x $85 per hour = $255........................... $0 $255 $4,080
----------------------------------------------------------------------------------------------------------------
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 x $85 per work-hour).
We estimate the following costs to do any necessary on-condition
actions that would be required based on the results of any required
actions. We have no way of determining the number of aircraft that
might need these on-condition actions:
Estimated Costs of On-Condition Actions
------------------------------------------------------------------------
Cost per
Labor cost Parts cost product
------------------------------------------------------------------------
6 work-hours x $85 per hour = $510.... $586 $1,096
------------------------------------------------------------------------
Authority for This Rulemaking
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.
Regulatory Findings
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.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.