Airworthiness Directive · Amendment 39-17678 · Fuel
Learjet Inc. Airplanes
This AD applies to Learjet Inc. Model 60 airplanes, certificated in any category, serial numbers 60-001 through 60-409 inclusive.
We are superseding Airworthiness Directive (AD) 2003-19-11 for certain Learjet Inc. Model 60 airplanes. AD 2003-19-11 required determining if a certain fuel crossflow tube is installed; and follow- on/corrective actions, as applicable. This new AD requires retaining all actions in AD 2003-19-11, and it also requires determining if a certain fuel crossflow tube is installed, performing repetitive measurements of the fuel crossflow tube and surrounding valves and cables, and doing corrective actions if necessary. In addition, this new AD expands the applicability of AD 2003-19-11. This AD was prompted by a report that airplanes produced since 2003 might also be subject to the unsafe condition; and that the minimum allowable clearance is not established in the airplane maintenance information. We are issuing this AD to prevent chafing and consequent failure of the fuel crossflow tube due to inadequate clearance between the tube and the flight control cables, which could result in loss of fuel from one fuel tank during normal operating conditions or loss of fuel from both main fuel tanks during fuel cross-feeding operations.
This paragraph restates the part identification required by paragraph (a) of AD 2003-19-11, Amendment 39-13314 (68 FR 55812, September 29, 2003). For airplanes having serial numbers 60-001 through 60-145 inclusive: Within 25 flight hours after November 3, 2003 (the effective date of AD 2003-19-11), inspect the fuel crossflow tube to determine whether part number (P/N) 6026020-005 is installed. Instead of inspecting the tube, a review of airplane maintenance records is acceptable if the part number of the tube can be positively determined from that review.
This paragraph restates the clearance measurement and corrective action required by paragraph (b) of AD 2003-19-11, Amendment 39-13314 (68 FR 55812, September 29, 2003), with revised repair language. For airplanes having serial numbers 60-001 through 60-145 inclusive: If P/N 6026020-005 is found installed during the review or inspection required by paragraph (g) of this AD, before further flight, measure the clearance between the fuel crossflow tube and the flight control cables to determine if it is at least 0.35 inch, per paragraph 2.B.(8) of the Accomplishment Instructions of Bombardier Alert Service Bulletin A60-28-3, Revision 2, dated October 26, 1998.
(1) If the clearance is 0.35 inch or more, no further action is required by this paragraph.
(2) If the clearance is less than 0.35 inch, before further flight, repair in accordance with a method approved by the Manager, Wichita Aircraft Certification Office (ACO), FAA. For a repair method to be approved by the Manager, Wichita ACO, as required by this paragraph, the Manager's approval letter must specifically refer to this AD.
Note 1 to paragraphs (h) and (j) of this AD: Bombardier Alert Service Bulletin A60-28-3, Revision 2, dated October 26, 1998, Figure 1, Detail D, incorrectly identifies the fuel crossflow tube to be installed as P/N 6026020-001. The manufacturer is aware of this error and stated it plans to correct the part number in the next revision of the service information.
This paragraph restates the part replacement, clearance measurement, and corrective action required by paragraph (c) of AD 2003-19-11, Amendment 39-13314 (68 FR 55812, September 29, 2003), with revised repair language. For airplanes having serial numbers 60-001 through 60-055 inclusive: If P/N 6026020-005 is not found installed during the review or inspection required by paragraph (g) of this AD, within 90 days after accomplishing the review or inspection, replace the existing fuel crossflow tube with a new fuel crossflow tube having P/N 6026020-005, and measure the clearance between the newly installed fuel crossflow tube and the flight control cables, per paragraph 2.A. of the Accomplishment Instructions of Bombardier Service Bulletin 60-28-4, Revision 2, dated August 22, 2001.
(1) If the clearance is 0.35 inch or more, no further action is required by this paragraph.
(2) If the clearance is less than 0.35 inch, before further flight, repair in accordance with a method approved by the Manager, Wichita ACO, FAA. For a repair method to be approved by the Manager, Wichita ACO, as required by this paragraph, the Manager's approval letter must specifically refer to this AD.
This paragraph restates the part replacement, clearance measurement, and corrective action required by paragraph (d) of AD 2003-19-11, Amendment 39-13314 (68 FR 55812, September 29, 2003), with revised repair language. For airplanes having serial numbers 60-056 through 60-145 inclusive: If P/N 6026020-005 is not found installed during the review or inspection required by paragraph (g) of this AD, within 90 days after accomplishing the review or inspection, replace the existing fuel crossflow tube with a new fuel crossflow tube having P/N 6026020-005, and measure the clearance between the newly installed fuel crossflow tube and the flight control cables to determine if the clearance is at least 0.35 inch, per paragraph 2.B. of the Accomplishment Instructions of Bombardier Alert Service Bulletin A60-28-3, Revision 2, dated October 26, 1998.
(1) If the clearance is 0.35 inch or more, no further action is required by this paragraph.
(2) If the clearance is less than 0.35 inch, before further flight, repair in accordance with a method approved by the Manager, Wichita ACO, FAA. For a repair method to be approved by the Manager, Wichita ACO, as required by this paragraph, the Manager's approval letter must specifically refer to this AD.
For airplanes having serial numbers 60-001 through 60-409 inclusive: Within 25 flight hours after the effective date of this AD, inspect the fuel crossflow tube to determine whether P/N 6026020-005 is installed. In lieu of inspecting the tube, a review of airplane maintenance records is acceptable if the part number of the tube can be positively determined from that review.
If P/N 6026020-005 is found installed during the inspection required by paragraph (k) of this AD, before further flight, measure the clearance between the fuel crossflow tube and both elevator control cables to determine if it is 0.35 inch or more, in accordance with paragraph 2.A.(9) of the Accomplishment Instructions of Bombardier Service Bulletin 60-28-4, Revision 2, dated August 22, 2001.
(1) If the clearance is 0.35 inch or more, no further action is required by this paragraph.
(2) If the clearance is less than 0.35 inch, before further flight, adjust the fit of the P/N 6026020-005 tube to provide 0.35 inch or more clearance to both elevator control cables, in accordance with paragraph 2.A.(9) of the Accomplishment Instructions of Bombardier Service Bulletin 60-28-4, Revision 2, dated August 22, 2001. If the tube shows any indication of chafing from the control cables, before further flight, replace the fuel crossflow tube with a new fuel crossflow tube, in accordance with paragraph 2.A.(9) of the Accomplishment Instructions of Bombardier Service Bulletin 60-28-4, Revision 2, dated August 22, 2001.
For all airplanes: As of the effective date of this AD and after accomplishing the inspection required by paragraph (g) or (k) of this AD, as applicable: Before further flight after removal, replacement, or adjustment of any crossflow tube, fuel crossflow drain valve, fuel crossflow valve or related plumbing and fittings, and elevator control cable, measure the clearance between the fuel crossflow tube and the flight control cables, in accordance with paragraph 2.A.(9) of the Accomplishment Instructions of Bombardier Service Bulletin 60-28-4, Revision 2, dated August 22, 2001.
(1) If the clearance is 0.35 inch or more, no further action is required by this paragraph.
(2) If the clearance is less than 0.35 inch, before further flight, adjust the fit of the P/N 6026020-005 tube to provide 0.35 inch or more clearance to both elevator control cables, in accordance with paragraph 2.A.(9) of the Accomplishment Instructions of Bombardier Service Bulletin 60-28-4, Revision 2, dated August 22, 2001.
Submit a report of the findings of the initial measurement required by paragraph (l) of this AD to the Wichita Manufacturing Inspection District Office, 2204 South Tyler Road, Wichita, KS 67209-3001, at the applicable time specified in paragraph (n)(1) or (n)(2) of this AD. The report must include the airplane registration, serial number, the total time in service, and the measured clearance found between the fuel crossflow tube and the elevator control cables after the initial inspection.
(1) If the inspection was done on or after the effective date of this AD: Submit the report within 30 days after the inspection.
(2) If the inspection was done before the effective date of this AD: Submit the report within 30 days after the effective date of this AD.
As of the effective date of AD, only fuel crossflow tubes having P/N 6026020-005 may be installed on any airplane.
A federal agency may not conduct or sponsor, and a person is not required to respond to, nor shall a person be subject to a penalty for failure to comply with a collection of information subject to the requirements of the Paperwork Reduction Act unless that collection of information displays a current valid OMB Control Number. The OMB Control Number for this information collection is 2120-0056. Public reporting for this collection of information is estimated to be approximately 5 minutes per response, including the time for reviewing instructions, completing and reviewing the collection of information. All responses to this collection of information are mandatory. Comments concerning the accuracy of this burden and suggestions for reducing the burden should be directed to the FAA at: 800 Independence Ave. SW., Washington, DC 20591, Attn: Information Collection Clearance Officer, AES-200.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
Aircraft
