Airworthiness Directive · Amendment 39-13901 · Short Brothers Model SD3-60, SD3-SHERPA, and SD3-60 SHERPA Series Airplanes
Short Brothers Model SD3-60, SD3-SHERPA, and SD3-60 SHERPA Series Airplanes
This AD applies to Short Brothers Model SD3-60, SD3-SHERPA, and SD3-60 SHERPA series airplanes; certificated in any category; that are equipped with aluminum alloy gland nuts, part number (P/N) 200920604, on the main landing gear (MLG) shock absorber.
The FAA is superseding an existing airworthiness directive (AD), which applies to certain Short Brothers Model SD3-60 and SD3- SHERPA series airplanes. That AD currently requires a one-time inspection to detect cracks and/or corrosion of the gland nut on the shock absorber of the main landing gear (MLG), and follow-on actions. That AD also requires repair or replacement of any cracked/corroded gland nut with a new nut. This new AD adds airplanes to the applicability; adds repetitive inspections and corrective actions; and provides an optional action that ends the repetitive inspections. This AD is prompted by reports of cracked aluminum alloy gland nuts that had been inspected previously using the existing AD. We are issuing this AD to prevent failure of the aluminum alloy gland nut on the MLG shock absorber, which could cause the MLG to collapse.
You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
The term “service bulletin,” as used in this AD, means the Accomplishment Instructions of the applicable service bulletin or service bulletins listed in the following paragraphs:
(1) For the requirements specified in paragraphs (g) and (h) of this AD, which are restated from AD 96-22-09, use the applicable service bulletins in Table 1 of this AD.
| Model | Service bulletin | Revision | Date |
|---|---|---|---|
| SD3-SHERPA series airplanes | SD3 SHERPA-32-2 | Original | September 22, 1995. |
| SD3-SHERPA series airplanes | SD3 SHERPA-32-2 | 1 | June 30, 2003. |
| SD3-60 series airplanes | SD360-32-34 | Original | September 22, 1995. |
| SD3-60 series airplanes | SD360-32-34 | 1 | June 30, 2003. |
(2) For the new requirements specified in paragraphs (i) and (j) of this AD, use the applicable service bulletin in Table 2 of this AD.
| Model | Service bulletin | Revision | Date |
|---|---|---|---|
| SD3-SHERPA series airplanes | SD3 SHERPA-32-2 | 1 | June 30, 2003. |
| SD3-60 SHERPA series airplanes | SD360 SHERPA-32-1 | Original | June 30, 2003. |
| SD3-60 series airplanes | SD360-32-34 | 1 | June 30, 2003. |
Note 1: The Messier-Dowty service bulletins listed in Table 3 of this AD are additional sources of service information for certain actions in the Shorts service bulletins.
| This Messier-Dowty service bulletin— | Is an additional source of service information for these shorts service bulletins— |
|---|---|
| 32-78SD, dated July 19, 1995 | SD3 SHERPA-32-2, dated September 22, 1995; and SD360-32-34, dated September 22, 1995. |
| 32-78SD, Revision 1, dated December 9, 2002 | SD360 SHERPA-32-1, dated June 30, 2003; and SD360-32-34, Revision 1, dated June 30, 2003. |
| 32-80SD, dated August 31, 2000 | SD360 SHERPA-32-1, dated June 30, 2003; SD3 SHERPA-32-2, Revision 1, dated June 30, 2003; and SD360-32-34, Revision 1, dated June 30, 2003. |
For Model SD3-60 series airplanes and Model SD3-SHERPA series airplanes: Within 90 days after December 11, 1996 (the effective date AD 96-22-09), perform a one-time visual and fluorescent dye penetrant inspection to detect cracks and/or corrosion of the gland nut on the shock absorber of the MLG, in accordance with the applicable service bulletin.
(1) If no crack and/or corrosion is detected, no further action is required by paragraph (g) of this AD.
(2) If no crack is detected, but corrosion is detected that is within the limits specified in the service bulletin, prior to further flight, repair the gland nut in accordance with the applicable service bulletin.
(3) If any crack is detected, or if any corrosion is detected that is outside the limits specified in the applicable service bulletin, prior to further flight, replace the gland nut with a new gland nut, in accordance with the applicable service bulletin.
(h) Following accomplishment of paragraph (g) of this AD, prior to further flight, apply grease to the threads of the cylinder, and apply sealant to the inner radius of the gland nut, in accordance with the applicable service bulletin.
(i) For all airplanes: Within 4 months after the effective date of this AD, do a detailed inspection of the P/N 200920604 gland nut on the MLG shock absorber for corrosion and/or cracking, and do any applicable corrective action before further flight, in accordance with the applicable service bulletin. Repeat the inspection at intervals not to exceed 12 months.
Note 2: For the purposes of this AD, a detailed inspection is: “An intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at an intensity deemed appropriate. Inspection aids such as mirror, magnifying lenses, etc., may be necessary. Surface cleaning and elaborate procedures may be required.”
Replacing the aluminum alloy gland nut, P/N 200920604, with a new steel gland nut, P/N 200920639, in accordance with the applicable service bulletin, terminates the requirements 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.
