AD 2006-10-15

The FAA is adopting a new airworthiness directive (AD) for certain Learjet Model 45 airplanes. This AD requires a review of airplane maintenance records to determine whether inspections identified by certain inspection reference numbers (IRNs) have been done. If any IRN has not been done, this AD requires doing an inspection of the inside of the wet wing fuel areas and the fuel pump screens for tape and adhesive tape residue, cleaning the low pressure fuel filter, determining whether tape or adhesive residue is present, doing an inspection of the filter for damage before installation, and applicable corrective actions if necessary. In addition, this AD requires sending the review and inspection results to the FAA. This AD results from reports of tape found in the wing fuel tanks. We are issuing this AD to prevent blocked fuel passages and fuel pump screens and the inability of the flightcrew to transfer fuel from one wing tank to the other tank due to tape in the wing fuel tanks, which could result in a fuel imbalance and consequent failure of an engine; and to prevent contaminated fuel pump screens, engine fuel controls, and fuel nozzles, due to tape adhesive dissolving in the fuel, which could result in potential erroneous readings of the fuel quantity indication system.

Final rule; request for comments.

2006-10-15 Learjet: Amendment 39-14599. Docket No. FAA-2006-24792; Directorate Identifier 2006-NM-102-AD.

Effective Date

(a) This AD becomes effective May 31, 2006.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Learjet Model 45 airplanes, serial numbers 45-005 through 45-295 inclusive, and 45-2001 through 45-2044 inclusive; certificated in any category.

Unsafe Condition

(d) This AD results from reports of tape found in the wing fuel tanks. We are issuing this AD to prevent blocked fuel passages and fuel pump screens and the inability of the flightcrew to transfer fuel from one wing tank to the other tank due to tape in the wing fuel tanks, which could result in a fuel imbalance and consequent failure of an engine; and to prevent contaminated fuel pump screens, engine fuel controls, and fuel nozzles due to tape adhesive dissolving in the fuel, which could result in potential erroneous readings of the fuel quantity indication system.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.

Review of Airplane Maintenance Records

(f) Within 50 flight hours or 30 days after the effective date of this AD, whichever occurs first, review the airplane maintenance records to determine whether inspections identified by the inspection reference numbers (IRNs) in paragraphs (f)(1) and (f)(2) of this AD have been done.

(1) IRN O2810001, Inspection/Service Requirement, "Wing Tanks " Perform Visual Inspection. Inspect for corrosion. (Refer to 5-10- 00.)," of Bombardier Learjet 45 M45 Maintenance Manual.

(2) IRN O2820000, Inspection/Service Requirement, "Low Pressure Fuel Filter " Remove and inspect for contamination. Clean if necessary. (Refer to 28-20-15.)," of Bombardier Learjet 45 M45 Maintenance Manual.

General Visual Inspections and Cleaning

(g) During the records review requiredby paragraph (f) of this AD, if it cannot be positively determined whether both IRNs have been done: Except as provided by paragraph (h) of this AD, within 50 flight hours or 30 days after the effective date of this AD, whichever occurs first, do the actions specified in paragraphs (g)(1) and (g)(2) of this AD in accordance with a method approved by the Manager, Wichita Aircraft Certification Office (ACO), FAA. Chapters 5-10-00 and 28-20-15, as applicable, of the Bombardier Learjet 45 M45 Maintenance Manual are approved methods.

(1) Do a general visual inspection of the inside of the wet wing fuel areas and the fuel pump screens for tape or adhesive tape residue.

(2) Clean the low pressure fuel filter, determining whether tape or adhesive tape residue is present, and do a general visual inspection of the filter for damage before installation.

Note 1: For the purposes of this AD, a general visual inspection is: "A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made from within touching distance unless otherwise specified. A mirror may be necessary to ensure visual access to all surfaces in the inspection area. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or droplight and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked."

(h) As of the effective date of this AD: If a crew alert system message of "L FUEL FILTER, R FUEL FILTER, LR FUEL FILTER, L FUEL PRESS LOW, R FUEL PRESS LOW, or LR FUEL PRESS LOW" occurs during flight or on the ground, do the actions required by paragraph (g) of this AD before further flight, unless those actions have already been done.

Corrective Actions

(i) If any tape or adhesive tape residue is found during the general visual inspection required by paragraph (g)(1) or during the cleaning required by paragraph (g)(2) of this AD, before further flight, do the actions specified in paragraphs (i)(1) and (i)(2) of this AD.

(1) Clean the wing fuel tank in accordance with a method approved by the Manager, Wichita ACO. Chapter 20-71-00 of the Bombardier Learjet 45 M45 Maintenance Manual is one approved method.

(2) Service the affected engine fuel filter and return any engine fuel control subjected to contaminated fuel for servicing to Honeywell Engines. Coordinate the return of the engine fuel control with Honeywell Engines, Systems & Services, Customer Support Center, M/S 26-06/2102-323, P.O. Box 29003, Phoenix, Arizona 85038-9003; telephone (800) 601-3099 or (602) 365-3099; fax (602) 365-3343.

(j) If any damage is found during the general visual inspection required by paragraph (g)(2) of this AD, before further flight, do the applicable action specified in paragraph (j)(1) or (j)(2) of this AD in accordance with a method approved by the Manager, Wichita ACO. Chapter 28-20-15 of the Bombardier Learjet 45 M45 Maintenance Manual is one approved method.

(1) For damage that is repairable: Repair damaged filter.

(2) For damage beyond repair: Replace the damaged filter with a new filter.

Reporting Requirement

(k) Within 10 days after accomplishing the review required by paragraph (f) of this AD or the general visual inspection required by paragraph (g) of this AD if done, whichever occurs later, submit a report of the applicable review and inspection results to: James Galstad, Aerospace Engineer, Systems and Propulsion Branch, ACE- 116W, FAA, Wichita Aircraft Certification Office, 1801 Airport Road, Room 100, Mid-Continent Airport, Wichita, Kansas 67209; e-mail james.galstad@faa.gov; telephone (316) 946-4135; fax (316) 946-4107. Information collection requirements contained in this AD have been approved by the Office of Management and Budget (OMB) under the provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.) and have been assigned OMB Control Number 2120-0056. The report must include the following, as applicable:

(1) The airplane serial number;

(2) The number of flight hours on the airplane;

(3) The applicable review and inspection results (both positive and negative findings), including a description, pictures, and pertinent information for any tape or adhesive tape residue found in the wing tank(s); and

(4) Date of inspection of the wing tank(s).

Alternative Methods of Compliance (AMOCs)

(l)(1) The Manager, Wichita ACO, 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 Sec. 39.19 on any airplane to which the AMOC applies, notify the appropriate principal inspector in the FAA Flight Standards Certificate Holding District Office.

Material Incorporated by Reference

(m) None.

Discussion

We have received four reports of tape found in the wing fuel tanks on Learjet Model 45 airplanes. In one case, the crew alert system (CAS) indication of a fuel filter impending bypass turned on in the cockpit, and in three cases, the tape was found during scheduled inspections. The cause of such fuel contamination has not been determined. Tape in the wing fuel tanks, if not corrected, could block fuel passages and fuel pump screens and could result in the inability of the flightcrew to transfer fuel from one wing tank to the other tank, which could result in a fuel imbalance and consequent failure of an engine. Tape adhesive dissolving in the fuel, if not corrected, could contaminate fuel pump screens, engine fuel controls, and fuel nozzles, which could result in potential erroneous readings of the fuel quantity indication system.

FAA's Determination and Requirements of this AD

The unsafe conditions described previously is likely to exist or develop on other airplanes of the same type design. For this reason, we are issuing this AD to prevent the identified unsafe conditions described previously. This AD requires a review of the airplane maintenance records to determine whether inspections identified by certain inspection reference numbers (IRNs) have been done. If any IRN has not been done, this AD requires doing an inspection of the inside of the wet wing fuel areas and the fuel pump screens for tape and adhesive tape residue, cleaning the low pressure fuel filter, determining whether tape or adhesive residue is present, doing an inspection of the filter for damage before installation, and applicable corrective actions if necessary. The corrective actions include cleaning any debris found in the wing fuel tank, returning any engine fuel control subjected to contaminated fuel for serving to the engine manufacturer, and repairing/replacing any damaged filter with a new filter; as applicable. In addition, this ADrequires sending the review and inspection results to the FAA.

FAA's Determination of the Effective Date

Since an unsafe condition exists that requires the immediate adoption of this AD, we have found that notice and opportunity for public comment before issuing this AD are impracticable, and that good cause exists to make this AD effective in less than 30 days.

Comments Invited

This AD is a final rule that involves requirements that affect flight safety and was not preceded by notice and an opportunity for public comment; however, we invite you to submit any relevant written data, views, or arguments regarding this AD. Send your comments to an address listed in the ADDRESSES section. Include "Docket No. FAA-2006- 24792; Directorate Identifier 2006-NM-102-AD" at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the AD that might suggest a need to modify it.

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 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 (800) 647- 5227) is located on the plaza level of the Nassif Building at the DOT street addressstated in the ADDRESSES section. Comments will be available in the AD docket shortly after the Docket Management System receives them.

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 AD will not have federalism implications under Executive Order 13132. This AD will 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 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 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.

Adoption of the Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 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.

Sec. 39.13 [Amended]

2. The Federal Aviation Administration (FAA) amends Sec. 39.13 by adding the following new airworthiness directive (AD):