Airworthiness Directive · Amendment 39-14469 · Short Brothers Model SD3-60 SHERPA, SD3-SHERPA, and SD3-60 Airplanes
Short Brothers Model SD3-60 SHERPA, SD3-SHERPA, and SD3-60 Airplanes
This AD applies to all Shorts Model SD3-60 SHERPA, SD3-SHERPA, and SD3-60 airplanes, certificated in any category.
The FAA is superseding an existing airworthiness directive (AD), which applies to all Short Brothers Model SD3-60 and SD3-SHERPA airplanes. That AD currently requires an inspection of the fork end of the rear pintle pin on each main landing gear (MLG) to verify that sealant is properly applied and is undamaged, and related investigative/corrective actions if necessary. This new AD requires an additional inspection for correctly applied sealant on the MLG rear pintle pin assemblies, and related investigative/corrective actions if necessary. This AD also expands the applicability of the existing AD. This AD results from a new report of a cracked pintle pin fork end. We are issuing this AD to prevent stress-corrosion cracking and subsequent failure of the MLG.
You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
For Model SD3-60 and SD3-SHERPA airplanes: Within 300 hours' time-in-service or 30 days after March 18, 1993 (the effective date of AD 93-02-03), whichever occurs first, perform a visual inspection of the fork end of the rear pintle pin on each MLG to verify that an undamaged fillet of sealant is properly applied around the flanges of the bronze bushings, in accordance with Shorts SD3-60 Service Bulletin SD360-32-33, dated August 7, 1992.
(1) If an undamaged fillet of properly applied sealant is found: No further action is required by this AD.
(2) If no fillet of sealant is found at the joint line, or if a damaged fillet of sealant is found: Prior to the accumulation of 1,200 hours' time-in-service or 120 days after accomplishing the inspection required by paragraph (f) of this AD, whichever occurs first, remove the bushings and perform a magnetic non-destructive testing (NDT) inspection to detect faults of the bores in the fork end, in accordance with the service bulletin. If faults are found as a result of the NDT inspection, prior to further flight, repair the fork end of the rear pintle pin in a manner approved by the Manager, International Branch, ANM-116, Transport Airplane Directorate, FAA.
For all airplanes: Within 3 months after the effective date of this AD, do a general visual inspection of the MLG rear pintle pin assemblies for correctly applied sealant, in accordance with Shorts Service Bulletin SD360-32-37, SD3 Sherpa-32-5, or SD360 Sherpa-32-4, all dated July 2004, as applicable.
(1) If the sealant is applied correctly: This AD requires no further work.
(2) If the sealant is applied incorrectly: Within 12 months after the effective date of this AD, do a magnetic flaw detection inspection to detect cracks of the rear pintle pin fork ends, in accordance with the service bulletin. If any cracked pintle pin fork end is found: Replace it before further flight with a serviceable part that has been inspected in accordance with the requirements of this AD.
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.”
Note 2: The service bulletins identified in paragraph (g) of this AD refer to Messier Dowty Special Inspection Service Bulletin 32-70SD, Revision 1, dated July 3, 1995, as an additional source of service information for the inspection and corrective actions.
(h) If any crack is detected during any inspection required by this AD and the service information specifies to contact the manufacturer for repair instructions: Before further flight, repair using a method approved by either the Manager, International Branch, ANM-116, Transport Airplane Directorate, FAA; or the Civil Aviation Authority (CAA) (or its delegated agent).
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.