The Rijksluchtvaartdienst (RLD), which is the airworthiness authority for the Netherlands, recently notified the FAA that an unsafe condition may exist on certain Fokker Model F28 Mark 0100 series airplanes. The RLD advises that it has received a report indicating that the Automatic Flight Control Augmentation System (AFCAS) on these airplanes does not properly monitor the radio altimeter status during automatic landing ("LAND 2") operations. As a result, an airplane may perform a "LAND 2" operation with only one radio altimeter that is operative. If the remaining altimeter were to fail or to lose track during the "LAND 2" operation, the ALIGN, FLARE, and/or RETARD modes will not be performed, even though the annunciations for these modes would still be indicated on the Electronic Flight Instrument System (EFIS). In this case, the flight crew may accept the EFIS annunciation that these maneuvers (modes) are being executed when, in fact, those maneuversare not taking place. This condition could result in the flight crew not being aware that the AFCAS has not properly aligned, flared, and retarded the airplane during automatic landing operations.
Explanation of Relevant Service Information
Fokker has issued Service Bulletin SBF100-34-015, Revision 2, dated November 27, 1990, which describes procedures for a modification of the radio altimeter wiring circuitry associated with the AFCAS data-control jumper. This wiring change will allow the radio altimeters to remove the data from AFCAS data bus whenever a failure is detected. As a result, "LAND 2" operation is no longer possible with only one radio altimeter operative. The RLD classified this service bulletin as mandatory and issued Netherlands airworthiness directive (BLA) 90-023, Issue 2, dated May 23, 1990, in order to assure the continued airworthiness of these airplanes in the Netherlands.
FAA's Conclusions
This airplane model is manufactured in the Netherlands and istype certificated for operation in the United States under the provisions of section 21.29 of the Federal Aviation Regulations (14 CFR 21.19) and the applicable bilateral airworthiness agreement. Pursuant to this bilateral airworthiness agreement, the RLD has kept the FAA informed of the situation described above. The FAA has examined the findings of the RLD, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States.
Explanation of Requirements of the Rule
Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design, this AD is being issued to prevent erroneous indications and failure of the AFCAS to properly align, flare, and retard the airplane during automatic landing operations when a single radio altimeter fails. This AD requires modification of the radio altimeter wiring circuitry associated with theAFCAS data-control jumper. The actions are required to be accomplished in accordance with the service bulletin described previously.
Cost Impact
None of the Model F28 Mark 0100 series airplanes affected by this action are on the U.S. Register. All airplanes included in the applicability of this rule currently are operated by non-U.S. operators under foreign registry; therefore, they are not directly affected by this AD action. However, the FAA considers that this rule is necessary to ensure that the unsafe condition is addressed in the event that any of these subject airplanes are imported and placed on the U.S. Register in the future.
Should an affected airplane be imported and placed on the U.S. Register in the future, it would require approximately 4.6 work hours to accomplish the required actions, at an average labor charge of $60 per work hour. The cost of required parts would be negligible. Based on these figures, the cost impact of this AD would be $276 per airplane.
Determination of Rule's Effective Date
Since this AD action does not affect any airplane that is currently on the U.S. register, it has no adverse economic impact and imposes no additional burden on any person. Therefore, notice and public procedures hereon are unnecessary and the amendment may be made effective in less than 30 days after publication in the Federal Register.
Comments Invited
Although this action is in the form of a final rule and was not preceded by notice and opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified under the caption "ADDRESSES." All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.
Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this rule must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket Number 96-NM-132-AD." The postcard will be date stamped and returned to the commenter.
Regulatory Impact
The regulations adopted herein will not have substantial direct effects 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. Therefore, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.
For the reasons discussed above, I certify that this action (1) is not a "significant regulatory action" under Executive Order 12866; (2) is not a "significant rule" under 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. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the locationprovided under the caption "ADDRESSES."
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.
Adoption of the Amendment
Accordingly, pursuant to 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. Section 39.13 is amended by adding the following new airworthiness directive: