Discussion
What events have caused this AD? We have received a report where the landing gear would not extend using normal operations and another report where certain electrical system components on the left generator and the center bus became inoperable.
The 200-amp current limiter, which protects the landing gear power wiring, did not operate correctly. This caused heat damage to the wiring in the landing gear power relay and surrounding electrical systems components.
The electrical system components that this condition potentially could affect include prop deice, surface deice, flaps, and left-hand windshield anti-ice.
Installing a 60-amp circuit breaker will protect the landing gear motor and associated circuitry from welding of the landing gear power relay contacts and sticking.
What is the potential impact if FAA took no action? If not corrected, this condition could cause heat damage to the electrical wiring in and around the landing gear electrical systems components. This condition could lead to loss of control of the airplane.
Has FAA taken any action to this point? We issued a proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that would apply to certain Raytheon Model 1900C airplanes. This proposal was published in the Federal Register as a notice of proposed rulemaking (NPRM) on November 5, 2003 (68 FR 62544). The NPRM proposed to require you to replace the 200-amp electrical power current limiter in the landing gear with a 60-amp electrical power circuit breaker.
Comments
Was the public invited to comment? We provided the public the opportunity to participate in the development of this AD. We received no comments on the proposal or on the determination of the cost to the public.
Conclusion
What is FAA's final determination on this issue? We have carefully reviewed the available data and determined that air safety and the public interest require adopting the AD as proposed except for minor editorial corrections. We have determined that these minor corrections:
--Are consistent with the intent that was proposed in the NPRM for correcting the unsafe condition; and
--Do not add any additional burden upon the public than was already proposed in the NPRM.
Changes to 14 CFR Part 39-Effect on the AD
How does the revision to 14 CFR part 39 affect this AD? On July 10, 2002, the FAA published a new version of 14 CFR part 39 (67 FR 47997, July 22, 2002), which governs the FAA's AD system. This regulation now includes material that relates to altered products, special flight permits, and alternative methods of compliance. This material previously was included in each individual AD. Since this material is included in 14 CFR part 39, we will not include it in future AD actions.
Costs of Compliance
How many airplanes does this AD impact? We estimate that this AD affects 25 airplanes in the U.S. registry.
What is the cost impact of this AD on owners/operators of the affected airplanes? We estimate the following costs to accomplish the modification:
Labor cost
Parts cost
Total cost per airplane
Total cost on U.S. operators
12 workhours x $65 per hour = $780
$672
$780 + $672 = $1,452
$1,452 x 25 = $36,300
Regulatory Findings
Will this AD impact various entities? We have determined that 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.
Will this AD involve a significant rule or regulatory action? 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); and
3. 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.
We prepared a summary of the costs to comply with this AD and placed it in the AD Docket. You may get a copy of this summary by sending a request to us at the address listed under ADDRESSES. Include "AD Docket No. 2003-CE-27-AD" in your request.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.
Adoption of the Amendment
Accordingly, under the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:
PART 39-AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
39.13 [Amended]2. FAA amends 39.13 by adding a new AD to read as follows: