Airworthiness Directive · Amendment 39-23238 · Main rotor system
PZL-Swidnik S.A. Helicopters
This AD applies to PZL-Swidnik S.A. Model PZL W-3A helicopters, certificated in any category.
The FAA is adopting a new airworthiness directive (AD) for certain PZL-Swidnik S.A. (Swidnik) Model PZL W-3A helicopters. This AD was prompted by the detection of corrosion on the main rotor blade (MRB) attachment bolts. This AD requires repetitively inspecting the MRB attachment bolts and, depending on the results of the inspection, repairing or replacing any affected bolts. This AD also requires reporting the inspection results and prohibits installing any MRB attachment bolt unless certain requirements are met. The FAA is issuing this AD to address the unsafe condition on these products.
(1) Within 100 hours time-in-service (TIS) or 3 months, whichever occurs first after the effective date of this AD:
(i) Remove each MRB attachment bolt part number (P/N) 37.21.000.50.00 and clean it, in accordance with Chapter II Accomplishment Instructions, paragraph 2.2 of PZL-Świdnik Alert Service Bulletin No. ASB-37-24-347, dated July 11, 2024 (PZL ASB-37-24-347).
(ii) Inspect each cleaned MRB attachment bolt for surface corrosion, pitting corrosion, or mechanical damage (defects), and damaged or missing protective coating as specified in Attachment 1, Criteria for Assessing Bolt Serviceability, paragraphs 1. and 2., of PZL ASB-37-24-347.
(iii) If there is any defect (surface corrosion, pitting corrosion, or mechanical damage), polish the affected area with sandpaper and determine if the MRB attachment bolt is within repairable limits as specified in Attachment 2, Bolt Repair, of PZL ASB-37-24-347.
(A) If the MRB attachment bolt is within repairable limits, before further flight repair the bolt in accordance with Attachment 2 Bolt Repair, of PZL ASB-37-24-347.
(B) If the MRB attachment bolt is beyond repairable limits, before further flight, remove the MRB attachment bolt from service and replace it with a serviceable bolt.
(2) Thereafter, repeat the actions required by paragraphs (g)(1)(i) through (iii) in accordance with the inspection intervals in table 1 to paragraph (g)(2) of this AD.
| Inspection results and/or action(s) accomplished during the last inspections | Repetitive intervals (hours TIS or calendar time, whichever occurs first) |
|---|---|
| No defects of any bolt and no damaged or missing protective coating of any bolt were found or The damaged or missing protective coating of each discrepant and each repaired bolt has been renewed/applied or All the discrepant bolts or all the affected parts have been replaced with serviceable parts | Within 300 hours TIS or 12 months, whichever occurs first, since the last inspection. |
| No defects of any bolt were found and for which the protective coating was found damaged during the last inspection and the protective coating has not been renewed | Within 25 hours TIS or 6 months, whichever occurs first, since the last inspection. |
(3) Within 30 days after each inspection required by this AD, report the inspection results to PZL-Swidnik S.A. The report must include the information specified in Chapter VI, paragraph 2.3 of PZL ASB-37-24-347.
As of the effective date of this AD, do not install an MRB attachment bolt P/N 37.21.000.50.00, on any helicopter unless it has been inspected in accordance with the requirements of this AD.
