FAA SPECIAL AIRWORTHINESS
Aviation Safety INFORMATION BULLETIN
SAIB: NM-17-06
SUBJ: Fuselage: Chem-Mill Skin Panels Date: January 4, 2017
This is information only. Recommendations aren’t mandatory.
Introduction
This Special Airworthiness Information Bulletin (SAIB) advises owners and operators of certain
The Boeing Company Model 737-200, -200C, -300, -400, and -500 series airplanes of a new
inspection procedure for cracking in the fuselage skin panels at the chem-mill steps.
Background
Airworthiness Directive (AD) 2011-24-12 and AD 2012-26-02, require inspections for cracking at
the chem-mill steps of the fuselage skin in several locations on the Boeing Model 737 series airplanes
listed above. The inspections use the Ultrasonic Phased Array methodology specified in the Boeing
Non Destructive Testing (NDT) Manual Part 4, Section 53-30-07, dated July 1, 2016. This NDT
methodology provides an adequate level of safety for compliance with those ADs.
To provide human factors improvements when inspecting large areas of the fuselage skin panels,
Boeing published a new inspection procedure in the Boeing 737 NDT Manual, Part 4, Section
53-30-12, dated November 1, 2016, in conjunction with its corresponding probe.
The FAA recently approved Boeing Alternative Method of Compliance (AMOC) Notices:
737-53A1234 AMOC 02, dated September 22, 2016, and 737-53A1301 AMOC 01, dated September
22, 2016, allowing the use of the procedure in the Boeing 737 NDT Manual, Part 4, Section 53-30-
12, dated November 1, 2016, as an acceptable alternative to NDT Manual Part 4, Section 53-30-07,
required by AD 2011-24-12 and AD 2012-26-02.
Recommendations
The FAA recommends that operators of the affected airplanes follow the inspection procedure
outlined in Boeing 737 NDT Manual, Part 4, Section 53-30-12, dated November 1, 2016.
For Further Information Contact
Jennifer Tsakoumakis, Aerospace Engineer, Airframe Branch, ANM-120L, FAA, Los Angeles
Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, CA 90712-4137; phone: 562-627-
5264; fax: 562-627-5210; email:
[email protected].
For Related Service Information Contact
Boeing Commercial Airplanes, Attention: Contractual & Data Services (C&DS), 2600 Westminster
Blvd., MC 110-SK57, Seal Beach, CA 90740; telephone 562-797-1717; Internet
https://www.myboeingfleet.com.
1
Please find attached a Foreign State of Design Advisory document, endorsed by EASA.
This advisory document is also online at http://ad.easa.europa.eu/ad/NM-17-06 .
Should you have any questions, please contact the Agency by e-mail at
[email protected] or by fax,
No.: +49 221 89990 9515.
Safety Information Section Email:
[email protected]
EASA Website
(Attachment is in Acrobat PDF format)
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