Airworthiness Directive · Amendment 39-18180 · Fuselage
Learjet Inc. Airplanes
This AD applies to Learjet Inc. Model 45 airplanes, certificated in any category, as identified in Bombardier Recommended Service Bulletin 40-56-03, Revision 1, dated October 15, 2012 (for airplanes having serial numbers (S/Ns) 45-2000 through 45-2120 inclusive, and S/Ns 45-2122 through 45-2130 inclusive); and Bombardier Recommended Service Bulletin 45-56-3, Revision 1, dated October 15, 2012 (for airplanes having S/Ns 45-005 through 45-427 inclusive).
We are adopting a new airworthiness directive (AD) for certain Learjet Inc. Model 45 airplanes. This AD was prompted by reports of non-conforming windshield supports (coupe rails). This AD requires a general visual inspection of the coupe rails to detect gouging and scratches, and to determine if a radius has been removed; an ultrasound inspection to measure the dimensions of the lower coupe rails; an eddy current inspection to detect cracks of the lower coupe rails; replacement of the lower coupe rails if necessary; and revision of the maintenance or inspection program, as applicable. We are issuing this AD to detect and correct non-conforming windshield supports, which could result in uncontrolled cabin depressurization and compromise of the capability of the windshield to withstand a bird strike.
Within 600 flight hours or 36 months after the effective date of this AD, whichever occurs first: Do the inspections specified in paragraphs (g)(1) through (g)(3) of this AD. Do all inspections and corrective actions specified in paragraphs (g)(1) through (g)(3) of this AD, in accordance with the Accomplishment Instructions of Bombardier Recommended Service Bulletin 40-56-03, Revision 1, dated October 15, 2012 (for airplanes having S/Ns 45-2000 through 45-2120 inclusive, and 45-2122 through 45-2130 inclusive); or Bombardier Recommended Service Bulletin 45-56-3, Revision 1, dated October 15, 2012 (for airplanes having S/Ns 45-005 through 45-427 inclusive).
(1) Do a general visual inspection of the coupe rails to detect gouging and scratches and to determine whether a radius has been removed or damaged.
(i) If gouging or scratches are found, before further flight, burnish or blend the gouges and scratches.
(ii) If the radius has been removed or damaged, before further flight, restore the radius.
(2) Do an ultrasound inspection to measure the dimensions of the lower coupe rails.
(i) If the coupe rail has an “X” dimension of 0.246 (6.248 millimeters (mm)) or greater, and a “Y” dimension of 0.148 (3.759 mm) or greater: Before further flight, identify the coupe rail, in accordance with table 1 of Bombardier Recommended Service Bulletin 40-56-03, Revision 1, dated October 15, 2012 (for airplanes having S/Ns 45-2000 through 45-2120 inclusive, and S/Ns 45- 2122 through 45-2130 inclusive); or Bombardier Recommended Service Bulletin 45-56-3, Revision 1, dated October 15, 2012 (for airplanes having S/Ns 45-005 through 45-427 inclusive).
(ii) If the coupe rail has an “X” dimension between 0.246 (6.248 mm) and 0.166 (4.216 mm) or a “Y” dimension between 0.148 (3.759 mm) and 0.134 (3.403 mm): Before further flight, identify the coupe rail, in accordance with table 2 of Bombardier Recommended Service Bulletin 40-56-03, Revision 1, dated October 15, 2012 (for airplanes having S/Ns 45-2000 through 45-2120 inclusive, and S/Ns 45- 2122 through 45-2130 inclusive); or Bombardier Recommended Service Bulletin 45-56-3, Revision 1, dated October 15, 2012 (for airplanes having S/Ns 45-005 through 45-427 inclusive).
(iii) If any coupe rail “X” dimension is below 0.166 (4.216 mm) or “Y” dimension is below 0.134 (3.403 mm): Before further flight, replace that coupe rail with a new coupe rail.
(3) Do a flange and radius eddy current inspection for cracks of the left-hand and right-hand lower coupe rails.
(i) If no crack is found, before further flight, mark the new data plate.
(ii) If any crack is found, before further flight, replace the coupe rail with a new coupe rail.
Within 30 days after the effective date of this AD: Revise the maintenance or inspection program (as applicable) to incorporate tasks for inspections of the lower coupe rail radius/windscreen retainer attach and replacement of the coupe rails, in accordance with a method approved by the Manager, Wichita Aircraft Certification Office (ACO), ACE-115W, FAA.
Note 1 to paragraph (h) of this AD: For Model 40 airplanes, the instructions provided in Bombardier Learjet 40 Maintenance Manual MM-105, Revision 30, dated June 2, 2014, provide guidance for revising the maintenance or inspection program to include replacements of the coupe rails and maintenance requirements/structure checks of the lower coupe rail radius/windscreen retainer attach. This service information is not incorporated by reference in this AD.
Note 2 to paragraph (h) of this AD: For Model 45 airplanes, the instructions provided in Bombardier Learjet 45 Maintenance Manual MM-104, Revision 62, dated June 2, 2014, provide guidance for revising the maintenance or inspection program to include replacements of the coupe rails and maintenance requirements/structure checks of the lower coupe rail radius/windscreen retainer attach. This service information is not incorporated by reference in this AD.
After accomplishing the revision required by paragraph (h) of this AD, no alternative IRN task or interval may be used unless the IRN task or interval is approved as an alternative method of compliance (AMOC) in accordance with the procedures specified in paragraph (k) of this AD.
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
