Airworthiness Directive · Amendment 39-11897 · Polskie Zaklady Lotnicze Spolka zo.o. Models PZL M18, PZL M18A, and PZL M18B Airplanes
Polskie Zaklady Lotnicze Spolka zo.o. Models PZL M18, PZL M18A, and PZL M18B Airplanes
This AD applies to Models PZL M18, PZL M18A, and PZL M18B airplanes, all serial numbers, certificated in any category.
This amendment adopts a new airworthiness directive (AD) that applies to all Polskie Zaklady Lotnicze Spolka zo.o. (PZL-Mielac) Models PZL M18, PZL M18A, and PZL M18B airplanes. This AD requires you to repetitively inspect the centerwing-to-outboard wing attach joints for cracks in the lugs, corrosion in the main holes, and ovalization of the main holes; repair corrosion and apply anti-corrosion protection; replace the wing attach joints, as necessary; and eliminate any ovalization of the wing main joint holes. This AD is the result two instances of in-flight wing separation on Model PZL M18A airplanes where severe corrosion and pitting led to high stress concentrations on the wing attachment joints. The actions specified by this AD are intended to detect and correct cracks in the lugs, corrosion in the main holes, and ovalization of the main holes, in the centerwing-to- outboard wing attach joints. Such damage could result in failure of the joints with consequent in-flight wing separation.
To address this problem, you must accomplish the following:
| Action | Compliance time | Procedures |
|---|---|---|
| (1) Inspect, using magnetic particle methods, the centerwing-to-outboard wing attach joints for cracks in the lugs, corrosion in the main holes, and ovalization of the main holes | (i) Initial inspection: Unless you have accomplished the required inspection since December 27, 1999 (9 months before the effective date of the AD), accomplish upon accumulating 3,000 hours time-in-service (TIS) on the airplane or within 30 days after September 27, 2000 (the effective date of this AD), whichever occurs later | As specified in Polskie Zak Ady Lotnicze Co. Ltd. Service Bulletin No. E/02.170/2000, dated August 3, 2000. Use the magnetic particle inspection procedures that are in the maintenance manual for these inspections. |
| (ii) Repetitive inspections: | ||
| (A) For existing attach joints: Within 500 hours TIS or 12 calendar months, whichever occurs first, after the initial inspection; and thereafter at intervals not to exceed 500 hours TIS or 12 calendar months, whichever occurs first. The first repetitive inspection starts at 12 calendar months after the last inspection for those airplanes that already had the initial inspection accomplished since December 27, 1999 (9 months before the effective date of this AD) | ||
| (B) For new attach joints: Upon accumulating 3,000 hours TIS on the joint, and thereafter at intervals not to exceed 500 hours TIS or 12 calendar months, whichever occurs first | ||
| (2) After each inspection, repair corrosion damage found to the extent allowed in the service bulletin and apply anti-corrosion protection | Prior to further flight after the inspection where the discrepancy was found | In accordance with the procedures in Polskie Zak Ady Lotnicze Co. Ltd. Service Bulletin No. E/02.170/2000, dated August 3, 2000. |
| (3) After each inspection, replace the wing attach joints if found cracked or if the corrosion damage is more than is specified in the service bulletin | Prior to further flight after the inspection where the discrepancy was found | In accordance with the procedures in Polskie Zak Ady Lotnicze Co. Ltd. Service Bulletin No. E/02.170/2000, dated August 3, 2000. |
| (4) After each inspection, eliminate any ovalization of the wing main joint holes | Prior to further flight after the inspection where the discrepancy was found | In accordance with the procedures in Polskie Zak Ady Lotnicze Co. Ltd. Service Bulletin No. E/02.170/2000, dated August 3, 2000. |
