Source: https://www.federalregister.gov/documents/2004/11/05/04-24723/airworthiness-directives-boeing-model-747-100-747-100b-747-100b-sud-747-200b-747-300-747sp-and-747sr
Timestamp: 2018-08-17 10:09:25
Document Index: 573502382

Matched Legal Cases: ['art 5', 'art 5', 'art 6', 'art 6', 'art 5', '§\u200939', 'art 1', 'art 6', 'art 5']

Federal Register :: Airworthiness Directives; Boeing Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-300, 747SP, and 747SR Series Airplanes
Airworthiness Directives; Boeing Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-300, 747SP, and 747SR Series Airplanes
69 FR 64525
64525-64530 (6 pages)
Docket No. FAA-2004-19535
Directorate Identifier 2004-NM-78-AD
04-24723
Requirements of AD 2002-18-04
Repetitive Inspections: Post-Modification/Repair
One-Time Inspection for Airplanes Inspected Previously
One-Time Inspection for Airplanes Modified/Repaired Previously
https://www.federalregister.gov/d/04-24723 https://www.federalregister.gov/d/04-24723
The FAA proposes to supersede an existing airworthiness directive (AD) for certain Boeing Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-300, 747SP, and 747SR series airplanes. That AD currently requires one-time inspections for cracking in certain upper deck floor beams and follow-on actions. This proposed AD would expand the existing inspection area, and would require inspecting fastener holes in certain areas of airplanes modified previously, and Start Printed Page 64526taking corrective actions if necessary. This action also would define new sources for instructions for repairs and post-modification/repair inspections. This proposed AD is prompted by reports of fatigue cracking of the upper chord of certain upper deck floor beams. We are proposing this AD to find and fix cracking in certain upper deck floor beams, which could extend and sever floor beams adjacent to the body frame and result in rapid depressurization and loss of controllability of the airplane.
You may examine the contents of this AD docket on the Internet at http://dms.dot.gov, or at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street, SW., room PL-401, on the plaza level of the Nassif Building, Washington, DC. This docket number is FAA-2004-19535; the directorate identifier for this docket is 2004-NM-78-AD.
Ivan Li, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 917-6437; fax (425) 917-6432.
We invite you to submit any written relevant data, views, or arguments regarding this proposed AD. Send your comments to an address listed under ADDRESSES. Include “Docket No. FAA-2004-19535; Directorate Identifier 2004-NM-78-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. We will consider all comments received by the closing date and may amend the proposed AD in light of those comments.
On August 30, 2002, we issued AD 2002-18-04, amendment 39-12878 (67 FR 57510, September 11, 2002), for certain Boeing Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-300, 747SP, and 747SR series airplanes. That AD requires one-time inspections for cracking in certain upper deck floor beams and follow-on actions. That AD was prompted by reports of fatigue cracking on the left and right ends of the upper chord of the station (STA) 340 upper deck floor beam on several Boeing Model 747 series airplanes. We issued that AD to find and fix cracking in certain upper deck floor beams. Such cracking could extend and sever floor beams adjacent to the body frame and result in rapid depressurization and loss of controllability of the airplane.
We've reviewed Boeing Service Bulletin 747-53A2459, Revision 1, dated March 11, 2004. Revision 1 of the service bulletin describes certain inspection procedures that are similar to those described in Boeing Alert Service Bulletin 747-53A2459, dated January 11, 2001, which AD 2002-18-04 refers to as the applicable source of service information for certain actions required by that AD. Revision 1 of the service bulletin, however, expands the inspection area to include fastener holes inboard of the body frame.
Part 5 of Revision 1 of the service bulletin describes procedures for post-modification/repair inspections. These inspections use the open-hole high-frequency eddy current (HFEC) inspection method. These inspections are intended to find cracking of the STA 340 and STA 360 upper deck floor beams at fastener holes common to the upper chord, reinforcement straps, and body frame. The service bulletin also describes procedures for surface HFEC inspections for cracking along the lower edge of the upper chord and reinforcement straps of the floor beams, which you can use as an alternative to the post-modification/repair open-hole HFEC inspections. (AD 2002-18-04 specifies that you must do post-modification/repair inspections in accordance with a method that we approve, or in accordance with data meeting the type certification basis of the airplane approved by an authorized Boeing Company Designated Engineering Representative (DER).) The service bulletin specifies repeating the inspection at intervals of 1,000 flight cycles (if you used the surface HFEC method for the most recent inspection), or 3,000 or 6,000 flight cycles, Start Printed Page 64527depending on fastener location (if you used the open-hole HFEC method for the most recent inspection).
Part 5 of the service bulletin also describes procedures for corrective actions if you find cracking during the post-modification/repair inspections. These corrective actions include repairing cracking of the floor beam and body frame, or replacing, with new parts:
The outboard end of the upper chord (if you find cracking of the upper chord).
The outboard end of the web (if you find cracking of the floor beam web).
The reinforcement strap (if you find cracking of the reinforcement strap).
Part 6 of Revision 1 of the service bulletin describes procedures for doing a one-time open-hole HFEC inspection of the fastener holes common to the reinforcement straps on airplanes that were modified in accordance with the original issue of the service bulletin, and taking corrective actions if necessary. The corrective actions in Part 6 are the same as those in Part 5, which we describe in the preceding paragraph.
We've evaluated all pertinent information and identified an unsafe condition that is likely to exist or develop on other products of this same type design. Therefore, we're proposing this AD, which would supersede AD 2002-18-04. This proposed AD would continue to require one-time inspections for cracking in certain upper deck floor beams, and other specified actions. This proposed AD would expand the existing inspection area to include fastener holes inboard of the body frame, and would require performing a one-time inspection for cracking of fastener holes in certain areas of airplanes modified previously, and taking corrective actions if necessary. This action also would define new sources for instructions for repairs and post-modification/repair inspections. This proposed AD would require you to use the service information described previously to do these actions, except as discussed under “Differences Between the Proposed AD and Service Bulletin.”
The service bulletin specifies doing the initial post-modification/repair inspections in accordance with Figures 12 and 13 of the service bulletin within 6,000 flight cycles after doing the modification or permanent repair. We've added a grace period of 1,000 flight cycles after the effective date of this AD for this inspection, to ensure that operators of airplanes that have accumulated close to or more than 6,000 flight cycles since the modification or permanent repair was done have sufficient time to perform these proposed inspections.
Using data that meet the type certification basis of the airplane, and that have been approved by a Boeing Company DER whom we've authorized to make such findings.
Although the Accomplishment Instructions of Boeing Service Bulletin 747-53A2459, Revision 1, describe procedures for reporting certain body frame cracks found on certain airplanes, this proposed AD would not require those actions. We don't need this information from operators.
For airplanes inspected previously in accordance with Boeing Alert Service Bulletin 747-53A2459 (but not previously modified or repaired), Boeing Service Bulletin 747-53A2459, Revision 1, does not specify a compliance time for inspecting the fastener holes inboard of the body frame that were added in Revision 1. Paragraph (j) of this proposed AD specifies these compliance times for that inspection:
Compliance Times for Paragraph (j)
Total number of accumulated flight cycles as of the effective date of this AD
22,000 or fewer Within 5,000 flight cycles after the initial open-hole HFEC inspection for cracking in accordance with paragraph (f) of this AD, or within 1,000 flight cycles after the effective date of this AD, whichever is later.
22,001 or more Prior to the accumulation of 25,000 total flight cycles, or within 1,000 flight cycles after the effective date of this AD, whichever is later.
In developing an appropriate compliance time for this inspection, we considered the manufacturer's recommended compliance times for the other inspections in this proposed AD, and the degree of urgency associated with the subject unsafe condition. In light of these factors, we find that the specified compliance times represent an appropriate interval of time for affected airplanes to continue to operate without compromising safety.
This proposed AD would retain all requirements of AD 2002-18-04. Since AD 2002-18-04 was issued, the AD format has been revised, and certain paragraphs have been rearranged. As a result, the corresponding paragraph identifiers have changed in this proposed AD, as listed in the following table:
Requirement in AD 2002-18-04
Also, AD 2002-18-04 estimated that the number of work hours necessary for the post-modification/repair inspection was 8 work hours per inspection cycle. We reached that estimate based on the best-available data at the time. As explained previously, Revision 1 of the service bulletin includes procedures for these inspections and estimates that they will take about 24 work hours. We've revised the “Costs of Compliance” section of this proposed AD accordingly.
This proposed AD would affect about 433 airplanes worldwide. The following table provides the estimated costs for U.S. operators to comply with this proposed AD.Start Printed Page 64528
No. of U.S.-registered airplanes
Initial inspections (required by AD 2002-18-04) 8 $65 $520 125 $65,000
Modification/permanent repair (required by AD 2002-18-04) 24 65 1,560 125 195,000
Post-mod/repair inspections (required by AD 2002-18-04) 24, per inspection cycle 65 1,560, per inspection cycle 125 195,000, per inspection cycle.
One-time inspection of fastener holes inboard of the body frame (new requirement) 24 65 1,560 N/A 1,560, per airplane.
2. The FAA amends § 39.13 by removing amendment 39-12878 (67 FR 57510, September 11, 2002) and adding the following new airworthiness directive (AD):
Boeing: Docket No. FAA-2004-19535; Directorate Identifier 2004-NM-78-AD.
(b) This AD supersedes AD 2002-18-04, amendment 39-12878.
(c) This AD applies to Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-300, 747SP, and 747SR series airplanes; line numbers 1 through 810 inclusive; certificated in any category; and not equipped with a nose cargo door.
(d) This AD was prompted by reports of fatigue cracking of the upper chord of certain upper deck floor beams. We are issuing this AD to find and fix cracking in certain upper deck floor beams, which could extend and sever floor beams adjacent to the body frame and result in rapid depressurization and loss of controllability of the airplane.
(f) At the compliance time specified in paragraph (f)(1) or (f)(2) of this AD, as applicable, perform one-time detailed and open-hole high-frequency eddy current (HFEC) inspections for cracking in the upper deck floor beams at station (STA) 340 and STA 360, in accordance with Boeing Alert Service Bulletin 747-53A2459, dated January 11, 2001; or Boeing Service Bulletin 747-53A2459, Revision 1, dated March 11, 2004. As of the effective date of this AD, only Revision 1 may be used. For the purposes of this AD, flight cycles with a cabin differential pressure of 2.0 psi or less are not calculated into the compliance thresholds specified in this AD. However, all cabin pressure records must be maintained for each airplane, and no fleet averaging of cabin pressure is allowed.
(1) For airplanes with 22,000 or fewer total flight cycles as of October 16, 2002 (the effective date of AD 2002-18-04, amendment 39-12878): Do the inspections prior to the accumulation of 16,000 total flight cycles, or within 1,500 flight cycles after October 16, 2002, whichever is later.
(2) For airplanes with more than 22,000 total flight cycles as of the effective date of this AD: Do the inspections within 500 flight cycles after October 16, 2002.
(g) If no crack is found during the inspections in accordance with paragraph (f) of this AD: Within 5,000 flight cycles after the initial inspections, modify the upper deck floor beams at STA 340 and STA 360, in accordance with Boeing Alert Service Bulletin 747-53A2459, dated January 11, 2001; or Boeing Service Bulletin 747-53A2459, Revision 1, dated March 11, 2004. As of the effective date of this AD, only Revision 1 may be used. If this modification is not done before further flight after the inspections required by paragraph (f) of this AD, those inspections must be repeated one time, immediately before accomplishing the modification in this paragraph. If any crack is found during these repeat inspections, before further flight, accomplish paragraph (h)(2) of this AD.
(h) If any crack is found during the inspections in accordance with paragraph (f) of this AD: Before further flight, repair in accordance with either paragraph (h)(1) or (h)(2) of this AD.
(1) Accomplish repairs in accordance with paragraphs (h)(1)(i) and (h)(1)(ii) of this AD.
(i) Accomplish a time-limited repair (including removing certain fasteners and the existing strap, performing open-hole HFEC inspections of the chord and web, stop-drilling web cracks, replacing the outboard section of the web, if applicable, and installing new straps) in accordance with Boeing Alert Service Bulletin 747-53A2459, dated January 11, 2001; or Boeing Service Start Printed Page 64529Bulletin 747-53A2459, Revision 1, dated March 11, 2004; except where the service bulletin specifies to contact Boeing for appropriate action, repair in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA; or in accordance with data meeting the type certification basis of the airplane approved by a Boeing Company Designated Engineering Representative (DER) who has been authorized by the Manager, Seattle ACO, to make such findings. For a repair method to be approved as required by this paragraph, the approval must specifically reference this AD. As of the effective date of this AD, only Revision 1 may be used.
(ii) Within 18 months or 1,500 flight cycles after installation of the time-limited repair in accordance with paragraph (h)(1)(i) of this AD, whichever is first, do paragraph (h)(2) of this AD.
(2) Accomplish a permanent repair in accordance with Boeing Alert Service Bulletin 747-53A2459, dated January 11, 2001; or Boeing Service Bulletin 747-53A2459, Revision 1, dated March 11, 2004; except where the service bulletin specifies to contact Boeing for appropriate action, repair in accordance with a method approved by the Manager, Seattle ACO; or in accordance with data meeting the type certification basis of the airplane approved by a Boeing Company DER who has been authorized by the Manager, Seattle ACO, to make such findings. For a repair method to be approved as required by this paragraph, the approval must specifically reference this AD. As of the effective date of this AD, only Revision 1 may be used.
(i) Within 15,000 flight cycles after modification of the upper deck floor beams in accordance with paragraph (g) of this AD or after permanent repair of the upper deck floor beams in accordance with paragraph (h) of this AD, as applicable: Perform either open-hole HFEC inspections for cracking of fastener holes common to the upper chord, reinforcement straps, and the body frame; or surface HFEC inspections for cracking along the lower edge of the upper chord of the floor beam at the intersection with the body frame; and repeat these inspections at the interval specified in paragraph (i)(1) or (i)(2) of this AD, as applicable, until the initial inspection required by paragraph (l) of this AD is complete. Perform these inspections and repair any cracking found during these inspections in accordance with a method approved by the Manager, Seattle ACO, or in accordance with data meeting the type certification basis of the airplane approved by a Boeing Company DER who has been authorized by the Manager, Seattle ACO, to make such findings. For an inspection or repair method to be approved as required by this paragraph, the approval must specifically reference this AD.
(1) If the most recent inspection used the surface HFEC method: Repeat the inspection within 1,000 flight cycles.
(2) If the most recent inspection used the open-hole HFEC method: Repeat the inspection every 3,000 flight cycles.
There is no terminating action at this time for the repetitive post-modification/repair inspections in accordance with paragraph (i) of this AD, and instructions for these inspections are not provided in the original issue of Boeing Alert Service Bulletin 747-53A2459, dated January 11, 2001.
(j) For airplanes on which the inspection in paragraph (f) of this AD has been done prior to the effective date of this AD in accordance with Boeing Alert Service Bulletin 747-53A2459, dated January 11, 2001, but the modification specified in paragraph (g) or the permanent repair specified in paragraph (h) of this AD has not been done: At the applicable time specified in Table 1 of this AD, do one-time detailed and open-hole HFEC inspections for cracking of the fastener holes inboard of the body frame that were not previously inspected on the STA 340 and STA 360 upper deck floor beams. Do this inspection in accordance with Part 1 of the Accomplishment Instructions of Boeing Service Bulletin 747-53A2459, Revision 1, dated March 11, 2004.
Table 1.—Compliance Times for Paragraph (j)
(k) For airplanes on which the modification specified in paragraph (g) or the permanent repair specified in paragraph (h) of this AD has been done prior to the effective date of this AD in accordance with Boeing Alert Service Bulletin 747-53A2459, dated January 11, 2001: At the applicable time specified in Table 2 of this AD, do a one-time open-hole HFEC inspection for cracking of fastener holes common to the modification straps, in accordance with Part 6 of the Accomplishment Instructions of Boeing Service Bulletin 747-53A2459, Revision 1, dated March 11, 2004.
Table 2.—Compliance Times for Paragraph (k)
Total number of accumulated flight cycles when the modification or permanent repair was done
22,000 or fewer Within 3,000 flight cycles after doing the modification or permanent repair, or 1,000 flight cycles after the effective date of this AD, whichever is later.
22,001 or more Within 1,500 flight cycles after doing the modification or permanent repair, or 1,000 flight cycles after the effective date of this AD, whichever is later.
(l) Do open-hole HFEC inspections for cracking of the STA 340 and STA 360 upper deck floor beams at fastener holes common to the upper chord, reinforcement straps, and body frame; or do surface HFEC inspections for cracking along the lower edge of the upper chord and reinforcement straps of the floor beams. Do the applicable inspection in accordance with Part 5 of the Accomplishment Instructions of Boeing Service Bulletin 747-53A2459, Revision 1, dated March 11, 2004. Do the initial inspections at the applicable times specified in Table 3 of this AD, and repeat the inspection at the applicable interval specified Start Printed Page 64530in Figure 9 of the service bulletin. Completing the initial inspection required by this paragraph terminates the repetitive inspections required by paragraph (i) of this AD. For airplanes on which paragraph (i) of this AD has not been done, doing the initial inspection required by this paragraph at the specified compliance time eliminates the need to comply with paragraph (i) of this AD.
Table 3.—Compliance Times for Initial Inspection Required by Paragraph (l)
For the inspections identified in the following figures referenced in figure 9 of the service bulletin—
For these airplanes—
Do the inspection—
Figure 10 or 11 Airplanes not inspected previously in accordance with paragraph (i) of this AD Within 15,000 flight cycles after doing the modification or permanent repair.
Figure 10 or 11 Airplanes inspected previously in accordance with paragraph (i) of this AD using the surface HFEC method for the most recent inspection Within 1,000 flight cycles after the most recent inspection.
Figure 10 or 11 Airplanes inspected previously in accordance with paragraph (i) of this AD using the open-hole HFEC method for the most recent inspection Within 3,000 flight cycles after the most recent inspection.
Figure 12 or 13 All airplanes Within 6,000 flight cycles after doing the modification or permanent repair, or within 1,000 flight cycles after the effective date of this AD, whichever is later.
(m) If any crack is found during any inspection required by paragraph (j), (k), or (l) of this AD: Before further flight, repair in accordance with the Accomplishment Instructions of Boeing Service Bulletin 747-53A2459, Revision 1, dated March 11, 2004; except where the service bulletin specifies to contact Boeing for appropriate action, repair in accordance with a method approved by the Manager, Seattle ACO; or in accordance with data meeting the type certification basis of the airplane approved by a Boeing Company DER who has been authorized by the Manager, Seattle ACO, to make such findings. For a repair method to be approved, the approval must specifically reference this AD.
(n) Although Boeing Service Bulletin 747-53A2459, Revision 1, dated March 11, 2004, specifies to report certain body frame cracks on certain airplanes, this AD does not include that requirement.
(o)(1) The Manager, Seattle ACO, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19.
(3) AMOCs approved previously in accordance with AD 2002-18-04, amendment 39-12878, are approved as alternative methods of compliance with paragraphs (f), (g), (h), and (i) of this AD.
[FR Doc. 04-24723 Filed 11-4-04; 8:45 am]