Airworthiness Directive · Amendment 39-14668 · Mitsubishi Heavy Industries MU-2B Series Airplanes
Mitsubishi Heavy Industries MU-2B Series Airplanes
This AD affects the following airplane models and serial numbers that are certificated in any category:
| Model | Serial Nos. |
|---|---|
| MU-2B-10 | 101 through 120 (Except 102, 114, 115, and 118). |
| MU-2B-15 | 114, 115, and 118. |
| MU-2B-20 | 102, and 121 through 238. |
| MU-2B-25 | 239 through 318 (Except 313), and 313SA. |
| MU-2B-26 | 319 through 347 (Except 321), and 349SA. |
| MU-2B-26A | 321SA, 348SA, and 350SA through 394SA (Except 365SA). |
| MU-2B-30 | 502 through 547. |
| MU-2B-35 | 548 through 654 (Except 652), and 652SA. |
| MU-2B-36 | 501, and 655 through 696 (Except 661). |
| MU-2B-36A | 661SA, and 697SA through 730SA (Except 700SA). |
| MU-2B-40 | 365SA. |
| MU-2B-60 | 700SA. |
We are adopting a new airworthiness directive (AD) for all Mitsubishi Heavy Industries MU-2B series airplanes. This AD requires you to do the following: Remove and visually inspect the wing attach barrel nuts, bolts, and retainers for cracks, corrosion, and fractures; replace any cracked, corroded, or fractured parts; inspect reusable wing attach barrel nuts and bolts for deformation and irregularities in the threads; check the minimum breakaway torque of reused wing attach barrel nuts; replace any deformed or irregular parts; and install new or reusable parts and torque to the correct value. This AD results from a recent safety evaluation that used a data-driven approach to evaluate the design, operation, and maintenance of the MU-2B series airplanes in order to determine their safety and define what steps, if any, are necessary for their safe operation. Part of that evaluation was the identification of unsafe conditions that exist or could develop on the affected type design airplanes. We are issuing this AD to detect and correct cracks, corrosion, fractures, and incorrect torque values in the wing attach barrel nuts, which could result in failure of the wing barrel nuts and/or associated wing attachment hardware. This failure could lead to in-flight separation of the outer wing from the center wing section and result in loss of controlled flight.
To address this problem, you must do the following, unless already done:
| Actions | Compliance | Procedures |
|---|---|---|
| (1) Remove each wing attach barrel nut, bolt, and retainer and do a visual inspection for cracks, corrosion, and fractures | Within the next 200 hours time-in-service or 12 months after August 11, 2006 (the effective detailed date of this AD), whichever occurs first, unless already done | Follow Mitsubishi Heavy Industries, Ltd. MU-2 Service Bulletins referenced as JCAB T.C.: No. 241, dated July 14, 2004, and FAA T.C.: No. 103/57-004A, dated March 10, 2006, as applicable. |
| (2) If any signs of cracks, corrosion, or fractures are found on any wing attach barrel nut during the inspection required in paragraph (e)(1) of this AD, replace that wing attach barrel nut, bolt, and retainer with new parts and install to the correct torque value | Before further flight after the inspection required in paragraph (e)(1) of this AD, unless already done | Follow Mitsubishi Heavy Industries, Ltd. MU-2 Service Bulletins referenced as JCAB T.C.: No. 241, dated July 14, 2004, and FAA T.C.: No. 103/57-004A, dated March 10, 2006, as applicable, and the appropriate maintenance manual. |
| (3) If no signs of cracks, corrosion, or fractures are found during the inspection required in paragraph (e)(1) of this AD, you may reuse the wing attach barrel nuts and bolts if they have been inspected and are free of deformation and irregularities in the threads and meet the minimum breakaway torque requirement. Reinstall inspected parts to the correct torque value. If the wing attach barrel nuts and bolts are not free of deformation and irregularities in the threads or do not meet the minimum breakaway torque requirement, install new parts to the correct torque value | Before further flight after the inspection required in paragraph (e)(1) of this AD, unless already done | Follow Mitsubishi Heavy Industries, Ltd. MU-2 Service Bulletins referenced as JCAB T.C.: No. 241, dated July 14, 2004, and FAA T.C.: No. 103/57-004A, dated March 10, 2006, as applicable, and the appropriate maintenance manual. |
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.
