Source: https://www.federalregister.gov/documents/2008/02/11/E8-2362/airworthiness-directives-fokker-model-f27-mark-050-airplanes
Timestamp: 2018-07-20 05:50:18
Document Index: 548785351

Matched Legal Cases: ['art 6', 'art 6', 'art 6', 'art 6', 'art 6', 'art 6', 'art 6', 'art 6', 'art 3', 'art 3', 'art 3']

73 FR 7663
Docket No. FAA-2008-0153
Directorate Identifier 2007-NM-243-AD
Amendment 39-15372
AD 2008-03-21
E8-2362
https://www.federalregister.gov/d/E8-2362 https://www.federalregister.gov/d/E8-2362
Recently, it was discovered that the inspection procedure as described by Fokker 50 Non-Destructive Testing Manual (NDTM), Part 6, Chapter 53-30-02, which is referenced by Fokker 50 Maintenance Review Board (MRB) Tasks Number 530000-00-04 and 530000-00-08 [currently required per AD (BLA) 2002-061], did not show the correct inspection areas. In addition to the existing procedure, the area at the kink in the bottom fuselage skin, the actual chine line, must be inspected. Investigation revealed that a number of aircraft have already passed the relevant inspection thresholds of 20,000 and 45,000 flight cycles by a considerable margin. As a result, it may be possible that cracks have developed and remained undetected. * * *
The unsafe condition is cracking and subsequent failure of the fuselage bottom skin, which could result in reduced structural integrity of the fuselage. This AD requires actions that are intended to address the unsafe condition described in the MCAI.
The Director of the Federal Register approved the incorporation by reference of certain publications listed in the AD as of February 26, 2008.
We must receive comments on this AD by March 12, 2008.
The Civil Aviation Authority—The Netherlands (CAA-NL), which is the aviation authority for the Netherlands, has issued Dutch Airworthiness Directive NL-2006-009 R1 dated September 28, 2006 (referred to after this as “the MCAI”), to correct an unsafe condition for the specified products. The MCAI states:
Recently, it was discovered that the inspection procedure as described by Fokker 50 Non-Destructive Testing Manual (NDTM), Part 6, Chapter 53-30-02, which is referenced by Fokker 50 Maintenance Review Board (MRB) Tasks Number 530000-00-04 and 530000-00-08 [currently required per AD (BLA) 2002-061], did not show the correct inspection areas. In addition to the existing procedure, the area at the kink in the bottom fuselage skin, the actual chine line, must be inspected. Investigation revealed that a number of aircraft have already passed the relevant inspection thresholds of 20,000 and 45,000 flight cycles by a considerable margin. As a result, it may be possible that cracks have developed and remained undetected. To prevent future use of the incorrect procedure in NDTM, Part 6, chapter 53-30-02, Fokker Services has removed this procedure from the NDTM and replaced by chapter 53-30-03 (refer to NDTM Temporary Revisions No. 53-004 and 53-005 dated September 15, 2006). Furthermore the Fokker 50/60 Maintenance Planning Document (refer to MPD Temporary Revision No. 53-009 dated August 15, 2006) has been revised to delete references to the incorrect procedure and to include references to the correct procedure of NDTM, Part 6, chapter 53-30-03. This condition, if not corrected, could result in failure of the fuselage bottom skin. Since an unsafe condition has been identified that is likely to exist or develop on aircraft of this type design, CAA-NL has originally published AD NL-2006-009, which is now replaced by NL-2006-009 R1.
This directive requires a one-time inspection of the fuselage bottom skin at the chine line, of the area not covered by the procedure of NDTM, Part 6, chapter 53-30-02. This one-time inspection consists of two parts:
—A detailed visual inspection. The visual inspection is described in Fokker Services Service Bulletin SBF50-53-058 (dated June 30, 2006).
—An eddy-current inspection. The eddy-current inspection is described in Fokker Services Service Bulletin SBF50-53-059 (dated August 24, 2006).
The unsafe condition is cracking and subsequent failure of the fuselage bottom skin, which could result in reduced structural integrity of the fuselage. Corrective actions include repairing any cracking. You may obtain further information by examining the MCAI in the AD docket.
Fokker Services B.V. has issued Service Bulletins SBF50-53-058, dated June 30, 2006, and SBF50-53-059, dated August 24, 2006. The actions described in this service information are intended to correct the unsafe condition identified in the MCAI.
This AD is a final rule that involves requirements affecting flight safety, and we did not precede it by notice and opportunity for public comment. We invite you to send any written relevant data, views, or arguments about this AD. Send your comments to an address listed under the ADDRESSES section. Include “Docket No. FAA-2008-0153; Directorate Identifier 2007-NM-243-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this AD. We will consider all comments received by the closing date and may amend this AD because of those comments.
2008-03-21 Fokker Services B.V: Amendment 39-15372. Docket No. FAA-2008-0153; Directorate Identifier 2007-NM-243-AD.
(c) This AD applies to Fokker Model F.27 Mark 050 airplanes, certificated in any category; serial numbers 20103 through 20172 inclusive.
Recently, it was discovered that the inspection procedure as described by Fokker 50 Non-Destructive Testing Manual (NDTM), Part 6, Chapter 53-30-02, which is referenced by Fokker 50 Maintenance Review Board (MRB) Tasks Number 530000-00-04 and 530000-00-08 [currently required per AD (BLA) 2002-061], did not show the correct inspection areas. In addition to the Start Printed Page 7665existing procedure, the area at the kink in the bottom fuselage skin, the actual chine line, must be inspected. Investigation revealed that a number of aircraft have already passed the relevant inspection thresholds of 20,000 and 45,000 flight cycles by a considerable margin. As a result, it may be possible that cracks have developed and remained undetected. To prevent future use of the incorrect procedure in NDTM, Part 6, chapter 53-30-02, Fokker Services has removed this procedure from the NDTM and replaced by chapter 53-30-03 (refer to NDTM Temporary Revisions No. 53-004 and 53-005 dated September 15, 2006). Furthermore the Fokker 50/60 Maintenance Planning Document (refer to MPD Temporary Revision No. 53-009 dated August 15, 2006) has been revised to delete references to the incorrect procedure and to include references to the correct procedure of NDTM, Part 6, chapter 53-30-03. This condition, if not corrected, could result in failure of the fuselage bottom skin. Since an unsafe condition has been identified that is likely to exist or develop on aircraft of this type design, CAA-NL has originally published AD NL-2006-009, which is now replaced by NL-2006-009 R1.
The unsafe condition is cracking and subsequent failure of the fuselage bottom skin, which could result in reduced structural integrity of the fuselage. Corrective actions include repairing any cracking.
(1) Before the accumulation of 20,000 total flight cycles, or within 3 weeks after the effective date of this AD, whichever occurs later, perform a detailed visual inspection for cracks of the fuselage bottom skin chine line between fuselage station (STA) 6675 and STA 15375 in accordance with Part 3, Steps A. and B., of the Accomplishment Instructions of Fokker Service Bulletin SBF50-53-058, dated June 30, 2006. If any crack is found appearing through the paint layer, before further flight, remove the paint to determine the extent of the cracking and repair in accordance with the instructions in the service bulletin.
(2) Before the accumulation of 45,000 total flight cycles, or within 3 weeks after the effective date of this AD, whichever occurs later, perform a detailed visual inspection for cracks of the fuselage bottom skin chine line between STA 1320 and STA 3100 in accordance with Part 3, Steps C. and D., of the Accomplishment Instructions of Fokker Service Bulletin SBF50-53-058, dated June 30, 2006. If any crack is found appearing through the paint layer, before further flight remove the paint to determine the extent of the cracking and repair in accordance with the instructions in the service bulletin.
(3) In all cases, whether or not cracks were found and repaired in accordance with the requirements in paragraphs (f)(1) and (f)(2) of this AD: Within 1,000 flight cycles after the visual inspections required by paragraphs (f)(1) and (f)(2) of this AD or within 1,000 flight cycles after the effective date of this AD, whichever occurs later, do an eddy current inspection of the fuselage bottom skin chine line (between the same fuselage stations as covered by the visual inspection) in accordance with Part 3 of the Accomplishment Instructions of Fokker Service Bulletin SBF50-53-059, dated August 24, 2006. If any crack is found during any eddy-current inspection, repair before further flight in accordance with the instructions in the service bulletin.
(4) If any crack is found as a result of any inspection requirement of this directive, within 30 days after the inspection or 30 days after the effective date of this AD, whichever occurs later, report all findings to the Type Certificate holder at the following address: Fokker Services B.V., Technical Services Dept., P.O. Box 231, 2150 AE Nieuw-Vennep, the Netherlands.
This AD differs from the MCAI and/or service information as follows: Although the MCAI or service information allows flight with cracks of different lengths on the fuselage bottom skin chine line between certain fuselage stations, this AD requires accomplishing the applicable repair before further flight if any crack is found.
(h) Refer to Mandatory Continuing Airworthiness Information (MCAI) CAA-NL Dutch Airworthiness Directive NL-2006-009 R1 dated September 28, 2006; and Fokker Service Bulletins SBF50-53-058, dated June 30, 2006, and SBF50-53-059, dated August 24, 2006; for related information.
(i) You must use Fokker Service Bulletin SBF50-53-058, dated June 30, 2006; and Fokker Service Bulletin SBF50-53-059, dated August 24, 2006; as applicable, to do the actions required by this AD, unless the AD specifies otherwise. Fokker Service Bulletin SBF50-53-059 contains the following effective pages:
1, 3, 5, 7, 9, 11, 13, 15 Original August 24, 2006.
2, 4, 6, 8, 10, 12, 14, 16 Original August 21, 2006.
[FR Doc. E8-2362 Filed 2-8-08; 8:45 am]