E8-2887. Airworthiness Directives; Boeing Model 737-600, -700, -700C, -800 and -900 Series Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

We propose to adopt a new airworthiness directive (AD) for certain Boeing Model 737-600, -700, -700C, -800 and -900 series airplanes. This proposed AD would require an inspection of the escape slides for the forward and aft entry and service doors to determine the part number and service bulletin number stenciled on the escape slide girt, and modification of the escape slide assemblies. This proposed AD also would require concurrent modification of the escape slide latch assembly; concurrent inspection of the escape slides to determine the part number and service bulletin number stenciled on the escape slide girts, and replacement of the trigger housing on the regulator valve with improved trigger housing if necessary; and concurrent replacement of the rod in the pilot valve regulator with a new improved rod; as applicable. This proposed AD results from reports that certain escape slides did not automatically inflate when deployed or after the manual inflation cable was pulled. We are proposing this AD to prevent failure of an escape slide to inflate when deployed, which could result in the slide being unusable during an emergency evacuation and consequent injury to passengers or crewmembers.

DATES:

We must receive comments on this proposed AD by March 31, 2008.

ADDRESSES:

You may send comments by any of the following methods:

• Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
• Fax: [phone].
• Mail: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590.
• Hand Delivery: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this AD, contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207.

Examining the AD Docket

You may examine the AD docket on the Internet at http://www.regulations.gov;​; or in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this proposed AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Office (telephone [phone]) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT:

Robert K. Hettman, Aerospace Engineer, Cabin Safety and Environmental Systems Branch, ANM-150S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue SW., Renton, Washington 98057-3356; telephone [phone], fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send any written relevant data, views, or arguments about this proposed AD. Send your comments to an address listed under the ADDRESSES section. Include “Docket No. FAA-2008-0176; Directorate Identifier 2007-NM-228-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. We will consider all comments received by the closing date and may amend this proposed AD because of those comments.

We will post all comments we receive, without change, to http://www.regulations.gov,, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this proposed AD.

Discussion

We have received reports indicating that Goodrich 5A3307 series escape slides did not automatically inflate when deployed on Boeing Model 737-600, -700, -700C, -800 and -900 series airplanes. On some of these airplanes, the escape slides did not inflate even after the manual inflation cable was pulled and the firing cable was pulled out of the valve regulator assembly. Investigation revealed that these escape slides did not inflate because the piston rod was incorrectly installed in the valve regulator assembly of the escape slide. The same valve regulator is also used on Goodrich 5A3086 and 5A3088 series escape slides. If the rod is installed upside down, the valve regulator assembly can be charged but the rod will prevent the regulator from activating when the firing cable is pulled. On other airplanes, the escape slides did not automatically inflate when deployed, but did inflate after the manual inflation cable was pulled. Investigation revealed that these escape slides did not automatically inflate because there was insufficient force to pull the inflation cable from the valve, due to the trigger housing cover deflecting the inflation cable. The failure of an escape slide to inflate when deployed, if not corrected, could result in the slide being unusable during an emergency evacuation and consequent injury to passengers or crewmembers.

Other Related Rulemaking

On July 13, 2001, we issued AD 2001-15-01, amendment 39-12335 (66 FR 38361, July 24, 2001), applicable to certain Boeing Model 727 and 737 airplanes; and Model 757-200, 757-200CB, and 757-300 series airplanes. That AD requires modification of the latch assembly of the escape slides. For Model 737-600, -700, and -800 series airplanes, that AD also requires installation of a cover assembly on the trigger housing of the inflation cylinder on the escape slides. For certain airplanes, this proposed AD specifies prior or concurrent accomplishment of certain requirements of paragraph (a) of AD 2001-15-01.

Relevant Service Information

We have reviewed Boeing Service Bulletin 737-25-1491, dated April 23, 2007. The service bulletin describes procedures for inspecting the escape slides to determine the Goodrich part number and service bulletin number stenciled on the escape slide girts, and for modifying the escape slide assemblies.

Boeing Service Bulletin 737-25-1491 refers to Goodrich Service Bulletin 25-338, Revision 1, dated March 31, 2004, as an additional source of service information for modifying the escape slide assemblies. The modification includes replacing the regulator piston plug in the vespel piston with a new piston plug, installing a new ensolite pad on the valise, and replacing the trigger housing cover with an improved trigger housing cover.

Concurrent Service Information

Boeing Service Bulletin 737-25-1491 also specifies prior or concurrent accomplishment of the following service bulletins:

• Boeing Service Bulletin 737-25-1404, dated May 25, 2000, or Revision 1, dated April 18, 2002, for certain Model 737-600, -700, and -800 series airplanes, equipped with any escape slide having P/N 5A3307-1, P/N 5A3307-3, P/N 5A3086-3, or P/N 5A3088-3. The original issue of the service bulletin is required by paragraph (a) of AD 2001-15-01. This service bulletin describes procedures for modifying the escape slide latch assembly.
• Boeing Special Attention Service Bulletin 737-25-1475, dated November 26, 2002, for Model 737-600, -700, -700C, -800 and -900 series airplanes equipped with any escape slide having P/N 5A3086-3 or P/N 5A3088-3. Boeing Special Attention Service Bulletin 737-25-1475 describes procedures for inspecting the four escape slides to determine the part number and service bulletin number stenciled on the escape slide girts, and replacing the trigger housing on the regulator valve with improved trigger housing if Goodrich Service Bulletin 5A3086/5A3088-25-302 is not stenciled on the girt. For certain airplanes, the Boeing service bulletin also specifies that a records review may be done in lieu of the inspection to determine the part number. Boeing Service Bulletin 737-25-1475 refers to Goodrich Service Bulletin 5A3086/5A3088-25-336, dated June 17, 2002, as an additional source of service information for replacing the trigger housing on the regulator valve with new improved trigger housing.
• Goodrich Service Bulletin 25-308, dated January 21, 2000, for any escape slide having P/N 5A3307-1, P/N 5A3086-3, or P/N 5A3088-3; or P/N 5A3307-3 and Goodrich Service Bulletin 5A3307-25-309 stenciled on the girt. Goodrich Service Bulletin 25-308 describes procedures for replacing the rod in the pilot valve regulator with a new improved rod.

Accomplishing the actions specified in the service information is intended to adequately address the unsafe condition.

FAA's Determination and Requirements of This Proposed AD

We are proposing this AD because we evaluated all relevant information and determined the unsafe condition described previously is likely to exist or develop in other products of the(se) same type design(s). This proposed AD would require accomplishing the actions specified in the service information described previously.

Clarification of Concurrent Service Information

Although Boeing Service Bulletin 737-25-1491 identifies Boeing Special Attention Service Bulletin 737-25-1403, dated May 4, 2000, or Revision 1, dated November 29, 2001; and Goodrich Service Bulletin 5A3307-25-309, dated October 29, 1999; as concurrent requirements, this proposed AD would not require accomplishment of those service bulletins. (Boeing Service Bulletin 737-25-1491 incorrectly dates the original issue of Boeing Special Attention Service Bulletin 737-25-1403 as November 29, 2001.) Instead, this proposed AD would require installing an improved trigger housing cover in accordance with Goodrich Service Bulletin 25-338. Goodrich Service Bulletin 25-338 incorporates a larger escape slide valise pad that provides the same shielding function as the trigger housing modification specified in Boeing Special Attention Service Bulletin 737-25-1403 and Goodrich Service Bulletin 5A3307-25-309. However, some operators might have previously incorporated Boeing Special Attention Service Bulletin 737-25-1403 and Goodrich Service Bulletin 5A3307-25-309 on certain Model 737-600, -700, and -800 series airplanes delivered with an escape slide having P/N 5A3307-1, as required by AD 2001-15-01. For these airplanes, this proposed AD would further require replacing the rod in the pilot valve regulator with a new improved rod in accordance with Goodrich Service Bulletin 25-308.

Although Boeing Service Bulletin 737-25-1491 identifies Goodrich Service Bulletin 5A3086/5A3088-25-302, dated November 13, 1998, or Revision 1, dated February 19, 2001, as a concurrent requirement, this proposed AD would not require accomplishment of that service bulletin. However, some operators might have previously accomplished the actions specified in Goodrich Service Bulletin 5A3086/5A3088-25-302. If Goodrich Service Bulletin 5A3086/5A3088-25-302 has been previously accomplished on Model 737-600, -700, -700C, -800 and -900 series airplanes equipped with any escape slide having P/N 5A3086-3 or P/N 5A3088-3, the trigger housing replacement specified in Boeing Special Attention Service Bulletin 737-25-1475 and Goodrich Service Bulletin 5A3086/5A3088-25-336 would not need to be accomplished.

Costs of Compliance

We estimate that this proposed AD would affect 480 airplanes of U.S. registry. We also estimate that it would take about 1 work-hour per product to comply with the proposed inspection. The average labor rate is $80 per work-hour. Based on these figures, we estimate the cost of this proposed AD to the U.S. operators to be $38,400 or $80 per product.

The following table provides the estimated costs, at an average labor rate of $80 per work-hour, for U.S. operators to comply with the proposed concurrent actions, if applicable.

Estimated Costs

Action	Work hours	Parts	Cost per airplane
Concurrent actions specified in Boeing Service Bulletin 737-25-1404	2	$1,424	$1,584
Concurrent actions specified in Boeing Special Attention Service Bulletin 737-25-1475	3	1,740	1,980
Concurrent actions specified in Goodrich Service Bulletin 25-308	3	516	756

Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. “Subtitle VII: Aviation Programs,” describes in more detail the scope of the Agency's authority.

We are issuing this rulemaking under the authority described in “Subtitle VII, Part A, Subpart III, Section 44701: General requirements.” Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

Regulatory Findings

We determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would not have a substantial direct effect on the States, on the relationship between the national Government and the States, or on the distribution of power and responsibilities among the various levels of government.

For the reasons discussed above, I certify this proposed regulation:

1. Is not a “significant regulatory action” under Executive Order 12866,

2. Is not a “significant rule” under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), and

3. Will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.

You can find our regulatory evaluation and the estimated costs of compliance in the AD Docket.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.

§ 39.13

[Amended]

2. The FAA amends § 39.13 by adding the following new AD:

Boeing: Docket No. FAA-2008-0176; Directorate Identifier 2007-NM-228-AD.

Comments Due Date

(a) We must receive comments by March 31, 2008.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Boeing Model 737-600, -700, -700C, -800 and -900 series airplanes, certificated in any category, as identified in Boeing Service Bulletin 737-25-1491, dated April 23, 2007.

Unsafe Condition

(d) This AD results from reports that certain escape slides did not inflate when deployed or after the manual inflation cable was pulled. We are issuing this AD to prevent failure of an escape slide to inflate when deployed, which could result in the slide being unusable during an emergency evacuation and consequent injury to passengers or crewmembers.

Compliance

(e) Comply with this AD within the compliance times specified, unless already done.

Inspection and Modification

(f) Within 36 months after the effective date of this AD, inspect the escape slides for the forward and aft entry and service doors to determine the Goodrich part number and service bulletin number stenciled on the escape slide girts, and modify the escape slide assemblies, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 737-25-1491, dated April 23, 2007.

Note 1:

Boeing Service Bulletin 737-25-1491 refers to Goodrich Service Bulletin 25-338, Revision 1, dated March 31, 2004, as an additional source of service information for modifying the escape slide assemblies.

Concurrent Requirements

(g) Prior to or concurrently with accomplishing the actions required by paragraph (f) of this AD, do the applicable actions specified in paragraphs (g)(1), (g)(2), and (g)(3) of this AD.

(1) For Model 737-600, -700, and -800 series airplanes identified in Boeing Service Bulletin 737-25-1404, dated May 25, 2000, equipped with any escape slide having P/N 5A3307-1, P/N 5A3307-3, P/N 5A3086-3, or P/N 5A3088-3: Modify the escape slide latch assembly in accordance with Boeing Service Bulletin 737-25-1404, dated May 25, 2000, as required by paragraph (a) of AD 2001-15-01; or Boeing Service Bulletin 737-25-1404, Revision 1, dated April 18, 2002.

(2) For Model 737-600, -700, -700C, -800 and -900 series airplanes equipped with any escape slide having P/N 5A3086-3 or P/N 5A3088-3: Inspect the four escape slides to determine the part number and service bulletin number stenciled on the escape slide girts, and replace the trigger housing on the regulator valve with improved trigger housing if Goodrich Service Bulletin 5A3086/5A3088-25-302 is not stenciled on the girt, in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 737-25-1475, dated November 26, 2002. For airplanes identified as Group 2 in the service bulletin, a records review may be done in lieu of the inspection to determine the part number.

Note 2:

Boeing Service Bulletin 737-25-1475 refers to Goodrich Service Bulletin 5A3086/5A3088-25-336, dated June 17, 2002, as an additional source of service information for replacing the trigger housing on the regulator valve with new improved trigger housing.

(3) For Model 737-600, -700, -700C, -800 and -900 series airplanes equipped with any escape slide having P/N 5A3307-1, P/N 5A3086-3, or P/N 5A3088-3; or P/N 5A3307-3 and Goodrich Service Bulletin 5A3307-25-309 stenciled on the girt: Replace the rod in the pilot valve regulator with a new improved rod in accordance with Goodrich Service Bulletin 25-308, dated January 21, 2000.

Terminating Action for AD 2001-15-01

(h) For Model 737-600, -700, and -800 series airplanes identified in Boeing Special Attention Service Bulletin 737-25-1403, dated May 4, 2000: Accomplishing the replacement of the regulator piston plug in the vespel piston with a new piston plug, installation of a new insolate pad on the valise, and removal of the trigger housing cover, in accordance with Goodrich Service Bulletin 25-338, Revision 1, dated March 31, 2004, terminates the modification specified in Boeing Special Attention Service Bulletin 737-25-1403, dated May 4, 2000, as required by paragraph (a) of AD 2001-15-01. All other applicable actions required by paragraph (a) of AD 2001-15-01 must be fully complied with.

(i) For Model 737-600, -700, and -800 series airplanes: Installation of a cover assembly on the trigger housing of the inflation cylinder on the escape slides in accordance with Boeing Special Attention Service Bulletin 737-25-1403, Revision 1, dated November 29, 2001, terminates the corresponding action required by paragraph (a) of AD 2001-15-01. All other applicable actions required by paragraph (a) of AD 2001-15-01 must be fully complied with.

(j) For Model 737-600, -700, and -800 series airplanes: Modification of the escape slide latch assembly in accordance with Boeing Service Bulletin 737-25-1404, Revision 1, dated April 18, 2002, terminates the corresponding action required by paragraph (a) of AD 2001-15-01. All other applicable actions required by paragraph (a) of AD 2001-15-01 must be fully complied with.

Alternative Methods of Compliance (AMOCs)

(k)(1) The Manager, Seattle Aircraft Certification Office, FAA, ATTN: Robert K. Hettman, Aerospace Engineer, Cabin Safety and Environmental Systems Branch, ANM-150S, 1601 Lind Avenue SW., Renton, Washington 98057-3356; telephone [phone], fax [phone]; has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19.

(2) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Before using any approved AMOC on any airplane to which the AMOC applies, notify your appropriate principal inspector (PI) in the FAA Flight Standards District Office (FSDO), or lacking a PI, your local FSDO.

Issued in Renton, Washington, on February 10, 2008.

Stephen P. Boyd,

Assistant Manager, Transport Airplane Directorate, Aircraft Certification Service.