E6-22282. Airworthiness Directives; Fokker Model F.28 Mark 0070 and 0100 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 airplanes. This proposed AD would require inspecting the carbon-fiber reinforced plastic (CFRP) main landing gear (MLG) door to determine whether certain part numbers are installed. For airplanes having certain doors, this proposed AD would require inspecting the MLG outboard door for cracks, play, and loose sealant/bolts/nuts, and related investigative and corrective actions if necessary. This proposed AD would also require, for airplanes having certain doors, modifying the rod bracket attachment of the MLG outboard door. This proposed AD results from a report of a rod bracket of the MLG door detaching during flight. We are proposing this AD to detect and correct cracks in the rod bracket attachment bolts, which could result in the rod brackets detaching from the MLG door and blocking the proper functioning of the MLG.

DATES:

We must receive comments on this proposed AD by January 29, 2007.

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.
• 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.

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

FOR FURTHER INFORMATION CONTACT:

Tom Rodriguez, Aerospace Engineer, International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; 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 in the ADDRESSES section. Include the docket number “FAA-2006-26709; Directorate Identifier 2006-NM-202-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 received 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 that Web site, 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 may review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78), or you may visit http://dms.dot.gov.

Examining the Docket

You may 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 Docket Management System 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 Fokker Model F.28 Mark 0070 and 0100 airplanes equipped with certain carbon-fiber reinforced plastic (CFRP) main landing gear (MLG) doors. The CAA-NL reports that a rod bracket of the MLG door of a Model F.28 Mark 0070 airplane detached during flight. Investigation showed that the operating rod between the MLG outboard door and the MLG fitting was broken and the rod's bracket was detached from the outboard door. The affected parts subsequently got stuck between the MLG and the outboard door hinge, resulting in damage to the two adjacent hydraulic lines. An investigation of a similar event revealed an operating rod bracket broken loose from the CFRP MLG door. Several other operators have also reported finding partly detached operating rod brackets. This condition, if not corrected, could result in rod brackets detaching from the CFRP MLG outboard door and blocking the proper functioning of the MLG.

Relevant Service Information

Fokker Services B.V. has issued Fokker Service Bulletin SBF100-52-080, dated December 12, 2005, including Fokker Manual Change Notification—Maintenance Documentation MCNM-F100-103, dated November 15, 2005.

In Part 1 of the Accomplishment Instructions of the service bulletin, the service bulletin describes procedures for doing a detailed inspection of the MLG outboard door for cracks, play, and loose sealant/bolts/nuts. The detailed inspection consists of the following actions:

• Inspecting for any cracks in the CFRP skin of the MLG outboard door.
• Inspecting for play between the countersunk bolt-heads and the CFRP outer skin.
• Inspecting for cracks in the paint.
• Inspecting for play between the operating rod bracket and the MLG outboard door.
• Inspecting for loose sealant around the edges of the bracket and loose bolts and nuts.

Part 1 of the service bulletin also describes doing the following related investigative action if play is found or if there are any loose bolts/nuts: Inspecting the inside of the door for cracks in the CFRP outer skin at the bolt hole locations and/or checking for delamination by tapping.

Part 1 of the service bulletin also describes doing one of the following corrective actions if play is found, if there are any loose bolts/nuts, or if any crack is found: Contacting Fokker, operating under Configuration Deviation List (CDL) item 52-07 (“operating with MLG strut bay doors missing”) of the Fokker Appendix CDL, to Fokker 70/Fokker 100 Airplane Flight Manual (AFM), Version 06, Issue 010, or doing the modification of the MLG outboard door operating rod bracket attachment specified in Part 2 of the service bulletin.

Part 2 of the Accomplishment Instructions of the service bulletin describes procedures for modifying the MLG outboard door operating rod bracket attachment. The modification includes installing internal and external reinforcement plates, reidentifying the outboard MLG door, and doing the following related investigative actions and corrective actions:

• Inspecting for damage of the operating rod bracket and operating rod.
• If any damage is found, doing one of the following: contacting Fokker, operating under CDL item 52-07, or replacing damaged part with a new part.
• Inspecting for cracks and and/or checking for delamination by tapping of the skin around the attachment holes.
• If any crack or delamination is found, doing one of the following: Repairing the cracks or delamination, or contacting Fokker if any crack or delamination is found beyond 10 millimeters (mm) (0.040 inches) from the bolt holes.

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 NL-2006-001, dated January 5, 2006, 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 airplanes 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 information described previously, except as discussed under “Differences Between the Proposed AD and the Service Bulletin.”

Difference Between the Proposed AD and the Service Bulletin

The service bulletin specifies to contact the manufacturer for instructions on how to repair certain conditions, but this proposed AD would require repairing those conditions using a method that we or the European Aviation Safety Agency (EASA) (or its delegated agent) approve. In light of the type of repair that would be required to address the unsafe condition, and consistent with existing bilateral airworthiness agreements, we have determined that, for this proposed AD, a repair we or the EASA approve would be acceptable for compliance with this proposed AD.

Clarification of Service Bulletin

Paragraph B.(3) of Part 1 of the Accomplishment Instructions of the service bulletin specifies to inspect for loose sealant and paragraph B.(6) specifies to inspect for delamination. However corrective actions for those conditions are not specified in the service bulletin. This proposed AD would require doing the corrective action specified in paragraph C.(3) of the service bulletin if any loose sealant or delamination is found during any inspection specified in paragraph (g) of the proposed AD.

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	Number of U.S.- registered airplanes	Fleet cost
Inspections	2	$80	$0	$160	7	$1,120
Modification	6	80	1,066	1,546	7	10,822

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 and placed it in the AD docket. 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 Federal Aviation Administration (FAA) amends § 39.13 by adding the following new airworthiness directive (AD):

Fokker Services B.V: Docket No. FAA-2006-26709; Directorate Identifier 2006-NM-202-AD.

Comments Due Date

(a) The FAA must receive comments on this AD action by January 29, 2007.

Affected ADs

(b) None.

Applicability

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

Unsafe Condition

(d) This AD results from a report of a rod bracket of the main landing gear (MLG) door detaching during flight. We are issuing this AD to detect and correct cracks in the rod bracket attachment bolts, which could result in the rod brackets detaching from the MLG door and blocking the proper functioning of the MLG.

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.

Inspections

(f) Within nine months after the effective date of this AD, inspect the carbon-fiber reinforced plastic (CFRP) MLG doors to determine if any MLG door having a part number (P/N) D13312-401 through -410 inclusive is installed. A review of airplane maintenance records is acceptable in lieu of this inspection if the part number of the CFRP MLG doors can be conclusively determined from that review. If the CFRP MLG doors have any part number other than P/N D13312-401 through -410 inclusive installed, no further action is required by this AD.

(g) If any CFRP MLG door having any P/N D13312-401 through-410 inclusive is found during the inspection required by paragraph (f) of this AD: Within nine months after the effective date of this AD, do a detailed inspection of the MLG outboard door for cracks, play, and loose sealant/bolts/nuts as specified in Part 1 of the Accomplishment Instructions of Fokker Service Bulletin SBF100-52-080, dated December 12, 2005, including Fokker Manual Change Notification—Maintenance Documentation MCNM-F100-103, dated November 15, 2005, and do all applicable related investigative and corrective actions, by doing all the applicable actions specified in Part 1 of the Accomplishment Instructions of the service bulletin, except as provided by paragraphs (i), (j), and (k) of this AD. Do all applicable related investigative and corrective actions before further flight.

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.”

Modification

(h) If any CFRP MLG door having any P/N D13312-401 through-410 inclusive is found during the inspection required by paragraph (f) of this AD: Within 12 months after the effective date of this AD, modify the MLG outboard door operating rod bracket attachment and do all applicable related investigative and corrective actions by doing all the applicable actions specified in Part 2 of the Accomplishment Instructions of Fokker Service Bulletin SBF100-52-080, dated December 12, 2005, including Fokker Manual Change Notification—Maintenance Documentation MCNM-F100-103, dated November 15, 2005, except as provided by paragraph (i) of this AD. Do all applicable related investigative and corrective actions before further flight.

Exceptions to the Service Bulletin

(i) Where Fokker Service Bulletin SBF100-52-080, dated December 12, 2005, including Fokker Manual Change Notification—Maintenance Documentation MCNM-F100-103, dated November 15, 2005, specifies to contact the manufacturer for repair, before further flight, repair using a method approved by either the Manager, International Branch, ANM-116, Transport Airplane Directorate, FAA; or the European Aviation Safety Agency (EASA) (or its delegated agent).

(j) If any loose sealant or any delamination is found during any inspection required by paragraph (g) of this AD, before further flight, do the corrective action specified in paragraph C.(3) of Part 1 of the Accomplishment Instructions of Fokker Service Bulletin SBF100-52-080, dated December 12, 2005, including Fokker Manual Change Notification—Maintenance Documentation MCNM-F100-103, dated November 15, 2005.

(k) Although the service bulletin referenced in this AD specifies to submit certain information to the manufacturer, this AD does not include that requirement.

Alternative Methods of Compliance (AMOCs)

(l)(1) The Manager, International Branch, ANM-116, Transport Airplane Directorate, FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19.

(2) Before using any AMOC approved in accordance with § 39.19 on any airplane to which the AMOC applies, notify the appropriate principal inspector in the FAA Flight Standards Certificate Holding District Office.

Related Information

(m) Dutch airworthiness directive NL-2006-001, dated January 5, 2006, also addresses the subject of this AD.

Issued in Renton, Washington, on December 19, 2006.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.