AD 96-14-08 ACTIVE

This amendment adopts a new airworthiness directive (AD), applicable to certain Fokker Model F28 Mark 0100 series airplanes. This action requires modification of the radio altimeter wiring circuitry associated with the Automatic Flight Control Augmentation System (AFCAS). This amendment is prompted by a report indicating that the AFCAS does not properly monitor the radio altimeter status during automatic landing operations. The actions specified in this AD are intended to prevent erroneous indications and failure of the AFCAS to properly align, flare, and retard the airplane during automatic landing operations if a single radio altimeter were to fail.

Final rule; request for comments

96-14-08 FOKKER: Amendment 39-9692. Docket 96-NM-132-AD.
Applicability: Model F28 Mark 0100 series airplanes; serial numbers 11244 through 11256 inclusive, 11259, 11260, and 11268 through 11273 inclusive; certificated in any category.

NOTE 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been otherwise modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (b) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously.

To prevent erroneous indications and failure of the AFCAS to properly align, flare, and retard the airplane during autoland operations when a single radio altimeter fails, accomplish the following:

(a) Within 6 months after the effective date of this AD, modify the radio altimeter wiring circuitry (AFCAS data-control jumper) in accordance with Fokker Service Bulletin SBF100-34-015, Revision 2, dated November 27, 1990.

(b) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Standardization Branch, ANM-113, FAA, Transport Airplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance or Avionics Inspector, who may add comments and then send it to the Manager, Standardization Branch, ANM-113.

NOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Standardization Branch, ANM-113.

(c) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished.

(d) The modification shall be done in accordance with Fokker Service Bulletin SBF100-34- 015, Revision 2, dated November 27, 1990, which contains the following list of effective pages:

Page Number
Revision Level
Shown on Page
Date
Shown on Page
1, 5
2
November 27, 1990
2-4, 6-9
1
May 16, 1990

This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Fokker Aircraft USA, Inc., 1199 North Fairfax Street, Alexandria, Virginia 22314. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

(e) This amendment becomes effective on July 24, 1996.

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:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-103, Attention: Rules Docket No. 96-NM-132-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.
The service information referenced in this AD may be obtained from Fokker Aircraft USA, Inc., 1199 North Fairfax Street, Alexandria, Virginia 22314. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

Tim Dulin, Aerospace Engineer, Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206) 227-2141; fax (206) 227-1149.