05-6759. Airworthiness Directives; Fokker Model F.28 Mark 0070 and 0100 Series Airplanes

AGENCY:

Federal Aviation Administration (FAA), Department of Transportation (DOT).

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for all Fokker Model F.28 Mark 0070 and 0100 series airplanes. This proposed AD would require repetitive inspections for damage of the drive rod assembly of the aileron tab on each aileron actuator; repetitive measurements of the clearance between the aileron hydraulic lines and the drive rod; and related investigative and corrective actions if necessary. This proposed AD is prompted by a report of an aileron 2 fault caused by severe wear of the polyamide washer that is part of an anti-rotation bush assembly in the aileron attachment lug. We are proposing this AD to prevent excessive wear of the polyamide washer of the aileron actuator bush assembly, which could result in aileron flutter and loss of control of the airplane.

DATES:

We must receive comments on this proposed AD by May 6, 2005.

ADDRESSES:

Use one of the following addresses to submit comments on this proposed AD.

• DOT Docket Web site: Go to http://dms.dot.gov and follow the instructions for sending your comments electronically.
• Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.
• Mail: Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street SW., Nassif Building, room PL-401, Washington, DC 20590.
• By fax: [phone].
• Hand Delivery: Room PL-401 on the plaza level of the Nassif Building, 400 Seventh Street SW., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this proposed AD, contact Fokker Services B.V., P.O. Box 231, 2150 AE Nieuw-Vennep, the Netherlands.

You can examine the contents of this AD docket on the Internet at http://dms.dot.gov, or in person at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street SW., room PL-401, on the plaza level of the Nassif Building, Washington, DC. This docket number is FAA-2005-20870; the directorate identifier for this docket is 2004-NM-180-AD.

FOR FURTHER INFORMATION CONTACT:

Tom Rodriguez, Aerospace Engineer, International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to submit any relevant written data, views, or arguments regarding this proposed AD. Send your comments to an address listed under ADDRESSES. Include “Docket No. FAA-2005-20870; Directorate Identifier 2004-NM-180-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. We will consider all comments submitted by the closing date and may amend the proposed AD in light of those comments.

We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this proposed AD. Using the search function of our docket website, anyone can find and read the comments in any of our dockets, including the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You can review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78), or you can visit http://dms.dot.gov.

Examining the Docket

You can examine the AD docket on the Internet at http://dms.dot.gov, or in person at the Docket Management Facility office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Management Facility office (telephone [phone]) is located on the plaza level of the Nassif Building at the DOT street address stated in the ADDRESSES section. Comments will be available in the AD docket shortly after the DMS receives them.

Discussion

The Civil Aviation Authority—The Netherlands (CAA-NL), which is the airworthiness authority for the Netherlands, notified us that an unsafe condition may exist on certain Fokker Model F.28 Mark 0070 and 0100 series airplanes. The CAA-NL advises that a Fokker Model F.28 0100 series airplane had an aileron 2 fault. Subsequent investigation showed severe wear of the polyamide washer that is used as part of an anti-rotation bush assembly in the aileron attachment lug. The worn washer allowed the aileron actuator to rotate inboard and caused the hydraulic unions at the actuator body to chafe through the drive rod of the aileron tab. This condition, if not corrected, could result in aileron flutter and loss of control of the airplane.

Relevant Service Information

Fokker Services B.V. has issued Fokker Service Bulletin SBF100-27-083, dated October 20, 2003. The service bulletin describes procedures for a one-time inspection for chafing damage of the drive rod of the aileron tab. If the drive rod shows chafing damage, the service bulletin gives procedures for corrective actions. The corrective actions include reworking the drive rod to determine the depth of the chafing damage and the straightness of the drive rod; and replacing the drive rod with a new or serviceable rod if necessary:

• For damage of less than or equal to .2 mm, no further action is required.
• For damage of greater than .2 mm but less than .5 mm, replace the drive rod within 4,000 flight hours after the inspection.
• For damage of greater than or equal to .5 mm but less than .8 mm, replace the drive rod within 500 flight hours after the inspection.
• For damage of .8 mm or greater, replace the drive rod before further flight.

The service bulletin also describes procedures for a one-time measurement for clearance between the aileron tab drive rod and the hydraulic lines of the aileron actuator. If the clearance is 4 mm or greater, the service bulletin states that no further action is required. If the clearance is less than 4 mm, the service bulletin gives procedures for one of two corrective actions: Replacing the polyamide washer with a new washer, or replacing the complete bush assembly with a new bush assembly.

After the polyamide washer or bush assembly is replaced, the service bulletin gives procedures for the related investigative action of re-measuring the clearance between the aileron tab drive rod and the aileron actuator hydraulic line. If the measurement is 4 mm or greater, the service bulletin states that no further action is required. If the measurement is less than 4 mm, the corrective action is replacing the aileron actuator with a serviceable aileron at an applicable interval, depending on the clearance:

• For clearance of 1 mm or less, replace the actuator before further flight.
• For clearance more than 1 mm, but 2 mm or less, replace the actuator within 500 flight hours after the measurement.
• For clearance of more than 2 mm to less than 4 mm, replace the actuator within 1,000 flight hours after the measurement.

Accomplishing the actions specified in the service information is intended to adequately address the unsafe condition. The CAA-NL mandated the service information and issued Dutch airworthiness directive 2003-141, dated November 28, 2003, to ensure the continued airworthiness of these airplanes in the Netherlands.

FAA's Determination and Requirements of the Proposed AD

These airplane models are manufactured in the Netherlands and are type certificated for operation in the United States under the provisions of section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. Pursuant to this bilateral airworthiness agreement, the CAA-NL has kept the FAA informed of the situation described above. We have examined the CAA-NL's findings, evaluated all pertinent information, and determined that we need to issue an AD for products of this type design that are certificated for operation in the United States.

Therefore, we are proposing this AD, which would require accomplishing the actions specified in the service bulletin described previously, except as discussed under “Difference Between the Proposed AD and the Dutch Airworthiness Directive.”

Clarification of Inspection Type

The service bulletin and the Dutch airworthiness directive do not specify the type of inspection to perform; we refer to the inspection as a ``detailed” inspection. Note 1 of this proposed AD defines a detailed inspection.

Difference Between the Proposed AD and the Dutch Airworthiness Directive

The Dutch airworthiness directive does not include intervals for repeating the inspections of the drive rod assembly of the aileron tab, and the measurement of the clearance between the hydraulic line and the aileron tab drive rod. Instead, the Dutch airworthiness directive states that the repetitive intervals will be introduced separately in updates of the Fokker 70/100 Maintenance Review Board (MRB) document and the Aircraft Maintenance Manual (AMM). The CAA-NL requires operators in The Netherlands to use the information, including repetitive intervals, in the latest revision of the MRB and the AMM. However, since the MRB and AMM are not mandatory in the U.S., this proposed AD would mandate that operators repeat the inspections and measurement at intervals not to exceed 4,000 flight hours. We have determined that this repetitive interval would mandate the equivalent intervals specified in the MRB and AMM, and would address the unsafe condition in the same manner.

This difference has been coordinated with the CAA-NL.

Costs of Compliance

The following table provides the estimated costs for U.S. operators to comply with this proposed AD.

Estimated Costs

Action	Work hours	Average labor rate per hour	Parts	Cost per airplane	No. of U.S.-registered airplanes	Fleet cost
Inspection	1	$65	None	$65	2	$130, per inspection cycle.

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.

Regulatory Findings

We have determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would 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 the proposed regulation:

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 regulatory evaluation of the estimated costs to comply with this proposed AD. See the ADDRESSES section for a location to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 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. The FAA amends § 39.13 by adding the following new airworthiness directive (AD):

Fokker Services B.V.: Docket No. FAA-2005-20870; Directorate Identifier 2004-NM-180-AD.

Comments Due Date

(a) The Federal Aviation Administration must receive comments on this AD action by May 6, 2005.

Affected ADs

(b) None.

Applicability

(c) This AD applies to all Fokker Model F.28 Mark 0070 and 0100 series airplanes, certificated in any category.

Unsafe Condition

(d) This AD was prompted by a report of an aileron 2 fault caused by severe wear of the polyamide washer that is part of an anti-rotation bush assembly in the aileron attachment lug. We are issuing this AD to prevent excessive wear of the polyamide washer of the aileron actuator bush assembly, which could result in aileron flutter and loss of control of the airplane.

Compliance

(e) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.

Service Bulletin Reference

(f) The term “service bulletin,” as used in this AD, means the Accomplishment Instructions of Fokker Service Bulletin SBF100-27-083, dated October 20, 2003.

Repetitive Inspections and Measurements

(g) Within 24 months or 4,000 flight hours after the effective date of this AD, whichever occurs earlier: Do the actions in paragraphs (g)(1) and (g)(2) of this AD in accordance with the service bulletin. Repeat the actions thereafter at intervals not to exceed 4,000 flight hours.

(1) Do a detailed inspection for chafing damage of the aileron tab drive rod assembly on each aileron actuator.

(2) Measure the clearance between the hydraulic line and the aileron tab drive rod.

Note 1:

For the purposes of this AD, a detailed inspection is: “An intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at an intensity deemed appropriate. Inspection aids such as mirror, magnifying lenses, etc., may be necessary. Surface cleaning and elaborate procedures may be required.”

Corrective Action for Chafing Damage

(h) If any chafing damage that is greater than .2 mm is found during any inspection required by paragraph (g)(1) of this AD, replace the drive rod in accordance with the service bulletin, at the applicable threshold limits defined in the service bulletin.

Corrective Action for Discrepant Clearance Measurements

(i) If any clearance measurement that is outside the limits defined in the service bulletin is found during the action required by paragraph (g)(2) of this AD, do the actions in paragraphs (i)(1) and (i)(2) of this AD. Do all actions in accordance with the service bulletin at the applicable threshold limits defined in the service bulletin.

(1) Replace the polyamide washer or replace the bush assembly.

(2) Do all applicable related investigative and corrective actions after the replacement in paragraph (i)(1) of this AD, including replacing the aileron actuator with a serviceable aileron actuator as applicable.

Alternative Methods of Compliance (AMOCs)

(j) The Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19.

Related Information

(k) Dutch airworthiness directive 2003-141, dated November 28, 2003, also addresses the subject of this AD.

Issued in Renton, Washington, on March 25, 2005.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.