AD 2014-15-01 Airworthiness Directives; M7 Aerospace LLC Airplanes

Models named: SA227-AT, SA227-AC, SA227-BC, SA227-CC, SA227-DC. Read the applicability below — it usually turns on serial or part numbers too.

This AD applies to the M7 Aerospace LLC airplanes listed in paragraphs (c)(1) through (c)(5) of this AD that are equipped with a bayonet shear pin main cabin door latching mechanism and are certificated in any category. Airplanes equipped with a “click-clack” main cabin door latching mechanism are not affected by this AD. Figure 3 of M7 Aerospace LLC SA227 Series Commuter Category Service Bulletin CC7-53-005, and M7 Aerospace LLC SA227 Series Service Bulletin 227-53-009, both dated November 15, 2013, is a picture showing both styles of latching mechanisms. (1) Model SA227-AT airplanes, serial numbers (S/Ns) AT570 through AT631, and AT695. (2) Model SA227-AC airplanes, S/Ns AC570 through AC788. (3) Model SA227-BC airplanes, S/Ns BC762, BC764, BC766, and BC770 through BC789. (4) Model SA227-CC airplanes, S/N CC827, CC829, and CC840 through CC844. (5) Model SA227-DC airplanes, S/Ns DC784, DC790 through DC826, DC828, DC830 through DC839, and DC845 through DC904.

Comply with this AD within the compliance times specified in paragraph (g) through paragraph (k) of this AD, including all subparagraphs, unless already done.

(1) Do the initial inspections of the fuselage upper forward corner and other 3 corners of the main cabin door cutout for cracks following Table 1 in Step 2. ACCOMPLISHMENT INSTRUCTIONS of M7 Aerospace LLC SA227 Series Commuter Category Service Bulletin CC7-53-005 or M7 Aerospace LLC SA227 Series Service Bulletin 227-53-009, both dated November 15, 2013, as applicable. Do the inspections at the compliance times specified in paragraphs (g)(1)(i) through (g)(1)(iv) of this AD. For the purposes of this AD, owner/operators who do not track total aircraft flight cycles (TAC), use a .5 to 1 conversion, e.g., 35,000 TAC is equivalent to 17,500 hours time-in-service (TIS). For owner/operators who do not track flight cycles, use a 1 to 1 conversion, e.g., 300 flight cycles are equivalent to 300 hours TIS. (i) For aircraft with more than 35,000 TAC, inspect within the next 300 flight cycles after August 27, 2014 (the effective date of this AD). (ii) For aircraft with 20,001—35,000 TAC, inspect within the next 600 flight cycles after August 27, 2014 (the effective date of this AD). (iii) For aircraft with 12,000—20,000 TAC, inspect within the next 1,000 flight cycles after August 27, 2014 (the effective date of this AD). (iv) For aircraft with less than 12,000 TAC, inspect at 12,000 flight cycles or within the next 1,000 flight cycles after August 27, 2014 (the effective date of this AD), whichever occurs later. (2) If no cracks are found during the inspections required by paragraph (g)(1) of this AD, repetitively thereafter at intervals not to exceed 2,000 flight cycles do the inspections of the fuselage upper forward corner and other 3 corners of the main cabin door cutout for cracks following Table 1 in Step 2. ACCOMPLISHMENT INSTRUCTIONS of M7 Aerospace LLC SA227 Series Commuter Category Service Bulletin CC7-53-005 or M7 Aerospace LLC SA227 Series Service Bulletin 227-53-009, both dated November 15, 2013, as applicable.

This AD was prompted by fatigue cracks found in the internal door surround doubler, the external skin fuselage skin, and the door corner fittings at the fuselage upper forward corner of the main cabin door cutout. We are issuing the AD to prevent decompression failure with possible loss of structural integrity of the cabin structure.

None.