E6-16894. Airworthiness Directives; Fokker Model F.28 Mark 1000, 2000, 3000, and 4000 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 1000, 2000, 3000, and 4000 airplanes. This proposed AD would require a one-time inspection of the left- and right-hand main landing gear (MLG) downlock actuators or a review of the airplane maintenance records to determine the part number of each downlock actuator installed, and replacement of identified MLG downlock actuators with modified MLG downlock actuators. This proposed AD results from a report of a failed downlock actuator, which resulted in the left MLG collapsing during taxi after landing. We are proposing this AD to prevent failure of the downlock actuator, which could prevent the MLG side stay from locking properly, resulting in collapse of the MLG during ground maneuvers or upon landing.

DATES:

We must receive comments on this proposed AD by November 13, 2006.

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, Transport Airplane Directorate, FAA, 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-2006-26044; Directorate Identifier 2006-NM-098-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 certain Fokker Model F.28 Mark 1000, 2000, 3000, and 4000 airplanes. The CAA-NL advises that it received a report that a flightcrew of a Model F.28 Mark 3000 airplane received a “LH MLG UNSAFE” warning during approach to landing. The flightcrew made an uneventful landing, but during taxi after landing the left main landing gear (MLG) collapsed. Investigation into the cause of the collapse revealed a failed downlock actuator. The failed downlock actuator prevented the MLG side stay assembly from locking properly, causing the MLG collapse. Investigators determined that the use of an improved (modified) version of the downlock assembly could prevent this condition. Failure of the downlock actuator, if not corrected, could prevent the MLG side stay from locking properly, resulting in collapse of the MLG during ground maneuvers or upon landing.

The MLG downlock actuators installed on Model F.28 Mark 1000, 2000, and 4000 airplanes are identical to those installed on the Model F.28 Mark 3000 airplanes. Therefore, all of these models may be subject to the identified unsafe condition.

Relevant Service Information

Fokker Services B.V. has issued Service Bulletin F28/32-163, dated March 8, 2004. The service bulletin describes procedures for removing the MLG downlock actuator, sending it to an approved Dowty Aerospace Hydraulics workshop for modification, and reinstalling the modified downlock actuator. The modification includes replacing certain parts (i.e., spring carrier, nuts, sub-assembly, certain end fittings, and bush inserts) and re-identifying certain other parts. 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 2004-047, dated April 20, 2004, to ensure the continued airworthiness of these airplanes in the Netherlands.

Fokker Service Bulletin F28/32-163 refers to Dowty Aerospace Hydraulics—Cheltenham Service Bulletin 32-501R, Revision 1, dated September 3, 1998, as an additional source of service information for modifying the MLG downlock actuator.

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 to require a one-time inspection of the left- and right-hand MLG downlock actuators or a review of the airplane maintenance records to determine the part number (P/N) of each MLG downlock actuator installed, and replacement of identified MLG downlock actuators with modified MLG downlock actuators.

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
Inspection of both MLG downlock actuators (2 per airplane)	1	$80	$0	$80	6	As much as $480.
Review of the airplane maintenance records in lieu of the inspection to determine P/N	1	80	0	80	6	As much as $480.
Replacement of the MLG downlock actuators (2 per airplane)	1 4	80	1 16,511	33,662	6	As much as $201,972.
1 Per actuator.

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-2006-26044; Directorate Identifier 2006-NM-098-AD.

Comments Due Date

(a) The FAA must receive comments on this AD action by November 13, 2006.

Affected ADs

(b) None.

Applicability

(c) This AD applies to all Fokker Model F.28 Mark 1000, 2000, 3000, and 4000 airplanes, certificated in any category.

Unsafe Condition

(d) This AD results from a report of a failed downlock actuator, which resulted in the left MLG collapsing during taxi after landing. We are issuing this AD to prevent failure of the downlock actuator, which could prevent the MLG side stay from locking properly, resulting in collapse of the MLG during ground maneuvers or upon landing.

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.

Determination of the Part Number (P/N) of the MLG Downlock Actuators

(f) Within 66 months after the effective date of this AD: Inspect the left- and right-hand MLG downlock actuators to determine if P/N 200497005 or 200498005 is installed. A review of airplane maintenance records is acceptable in lieu of this inspection if the P/N of the MLG downlock actuators can be conclusively determined from that review. If an MLG downlock actuator does not have a subject P/N, no further action is required by this AD for that MLG only, except as provided by paragraph (h) of this AD.

Replacement of Subject MLG Downlock Actuators

(g) For any MLG downlock actuator identified during the inspection or maintenance records review required by paragraph (f) of this AD, or for which the P/N cannot be determined: Within 66 months after the effective date of this AD, replace the MLG downlock actuator with a modified MLG downlock actuator in accordance with the Accomplishment Instructions of Fokker Service Bulletin F28/32-163, dated March 8, 2004.

Note 1:

Fokker Service Bulletin F28/32-163 refers to Dowty Aerospace Hydraulics—Cheltenham Service Bulletin 32-501R, Revision 1, dated September 3, 1998, as an additional source of service information for modifying the MLG downlock actuator.

Parts Installation

(h) As of the effective date of this AD, no person may install an MLG downlock actuator, P/N 200497005 or 200498005, on any airplane.

Alternative Methods of Compliance (AMOCs)

(i)(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

(j) Dutch airworthiness directive 2004-047, dated April 20, 2004, also addresses the subject of this AD.

Issued in Renton, Washington, on October 3, 2006.

Kalene C. Yanamura,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.