05-9469. Airworthiness Directives; Boeing Model 747 Airplanes

AGENCY:

Federal Aviation Administration (FAA), Department of Transportation (DOT).

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for certain Boeing Model 747 airplanes. This proposed AD would require modifying the inflation systems of the upper deck escape slides; single-piece off-wing escape ramps/slides; two-piece off-wing escape slides; and door 1, 2, 4, and 5 escape slides/rafts. This proposed AD is prompted by a report of 30- to 60-second delays in the inflation of escape slides/rafts. We are proposing this AD to prevent actuation delays in the inflation systems of the escape slides/rafts, which could result in delayed or failed deployment of escape slides/rafts during emergency evacuation of an airplane.

DATES:

We must receive comments on this proposed AD by June 27, 2005.

ADDRESSES:

Use one of the following addresses to submit comments on this proposed AD.

• DOT Docket Web site: Go to http://dms.dot.gov and follow the instructions for sending your comments electronically.
• Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.
• Mail: Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street SW., Nassif Building, room PL-401, Washington, DC 20590.
• By fax: [phone].
• Hand Delivery: Room PL-401 on the plaza level of the Nassif Building, 400 Seventh Street SW., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

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

You can 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-2005-21184; the directorate identifier for this docket is 2004-NM-111-AD.

FOR FURTHER INFORMATION CONTACT:

Donald Wren, Aerospace Engineer, Cabin Safety and Environmental Systems Branch, ANM-150S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to submit any relevant written data, views, or arguments regarding this proposed AD. Send your comments to an address listed under ADDRESSES. Include “Docket No. FAA-2005-21184; Directorate Identifier 2004-NM-111-AD” in the subject line 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 submitted by the closing date and may amend the proposed AD in light of those comments.

We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this proposed AD. Using the search function of that Web site, anyone can find and read the comments in any of our dockets, including the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You can review DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78), or you can visit http://dms.dot.gov.

Examining the Docket

You can examine the AD docket on the Internet at http://dms.dot.gov, or in person at the Docket Management Facility office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Management Facility office (telephone [phone]) is located on the plaza level of the Nassif Building at the DOT street address stated in the ADDRESSES section. Comments will be available in the AD docket shortly after the DMS receives them.

Discussion

We have received a report indicating that, during testing, an operator observed 30- to 60-second delays in the inflation of escape slides/rafts on two Boeing Model 747-200B and -400 series airplanes. Insufficient margin between regulator internal friction and piston actuator force caused the actuation delays in the inflation systems of the escape slides/rafts. This condition, if not corrected, could result in delayed or failed deployment of escape slides/rafts during emergency evacuation of an airplane.

The inflation systems of the upper deck escape slides; single-piece off-wing escape ramps/slides; two-piece off-wing escape slides; and door 1, 2, 4, and 5 escape slides/rafts; on certain Model 747-100, -100B, -100B SUD, -200C, -200F, -300, -400D, -400F, 747SP, and 747SR series airplanes are identical to those on the affected Model 747-200B and -400 series airplanes. Therefore, all of these models may be subject to the same unsafe condition.

Relevant Service Information

We have reviewed the following service bulletins:

• For certain Model 747-100, -100B, -100B SUD, -200B, -200C, -200F, -300, -400F, 747SP, and 747SR series airplanes, Boeing Service Bulletin 747-25-3279, Revision 1, dated July 11, 2002; and
• For certain Model 747-200B, -200C, -300, -400, and -400D series airplanes, Boeing Service Bulletin 747-25-3232, dated July 6, 2000.

Boeing Service Bulletin 747-25-3279 describes procedures for modifying the inflation systems of the upper deck escape slides; two-piece off-wing escape slides; and door 1, 2, 4, and 5 escape slides/rafts. Boeing Service Bulletin 747-25-3232 describes procedures for modifying the inflation system of the single-piece off-wing escape ramps/slides. For both Boeing Service Bulletins 747-25-3279 and 747-25-3232, modification includes replacing the plug of the regulator assembly with a pneumatic booster assembly, and replacing the lobed cocking arm in the actuator assembly with a new cocking arm (not lobed).

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

Additional Sources of Service Information

Boeing Service Bulletin 747-25-3279 refers to the following service bulletins as additional sources of service information:

• Goodrich Service Bulletin 4A3037-25-327, dated November 30, 2001, for modifying the inflation systems of the upper deck and two-piece off-wing escape slides.
• Goodrich Service Bulletin 4A3056-25-331, dated December 21, 2001; and Goodrich Service Bulletin 4A3221-25-332, dated December 21, 2001; for modifying the inflation systems of the door 1, 2, 4, and 5 escape slides/rafts.

Boeing Service Bulletin 747-25-3232 refers to Goodrich Service Bulletin 4A3416-25-305, Revision 2, dated October 15, 2001, as an additional source of service information for modifying the inflation system of the single-piece off-wing escape ramps/slides.

Concurrent Service Bulletins to Additional Sources of Service Information

Goodrich Service Bulletin 4A3037-25-327 specifies prior or concurrent accomplishment of BFGoodrich Service Bulletin 4A3012/4A3047-25-256, Revision 1, dated October 27, 1999, for regulator assemblies having part numbers (P/N) 4A3047-3 and -4.

Goodrich Service Bulletin 4A3056-25-331 also specifies prior or concurrent accomplishment of BFGoodrich Service Bulletin 4A3012/4A3047-25-256 for regulator assemblies with P/Ns 4A3047 and 4A3047-2.

Goodrich Service Bulletin 4A3221-25-332 specifies prior or concurrent accomplishment of BFGoodrich Service Bulletin 4A3221-25-250, Revision 3, dated October 27, 1999, for regulator assemblies with P/Ns 4A3194-1, -2, and -3.

BFGoodrich Service Bulletin 4A3012/4A3047-25-256 and BFGoodrich Service Bulletin 4A3221-25-250 both describe procedures for replacing the actuator assembly with a new actuator assembly; replacing the compression spring with a new compression spring; and replacing the existing lubricant in the regulator valve with new, improved lubricant during overhaul.

Goodrich Service Bulletin 4A3416-25-305 specifies prior or concurrent accomplishment of the following service bulletins for a regulator assembly having P/N 4A3474-3:

• BFGoodrich Service Bulletin 25-292, Revision 1, dated December 19, 1997, which describes procedures for replacing the o-rings of the regulator assembly with new, improved o-rings;
• BFGoodrich Service Bulletin 4A3416-25-233, Revision 4, dated October 27, 1999, which describes procedures for modifying the regulator core; and replacing the existing lubricant in the regulator valve with new, improved lubricant during overhaul; and
• BFGoodrich Service Bulletin 7A1418-25-253, Revision 2, April 15, 1994, which describes procedures for modifying the reservoir assembly of the regulator assembly; and modifying the inflatable assembly.

FAA's Determination and Requirements of the Proposed AD

We have evaluated all pertinent information and identified an unsafe condition that is likely to exist or develop on other airplanes of this same type design. Therefore, we are proposing this AD, which would require accomplishing the actions specified in the service information described previously, except as discussed under “Difference Between the Proposed AD and Service Information.”

Difference Between the Proposed AD and Service Information

Although the Boeing service bulletins recommend accomplishing the modification at “the next scheduled evacuation system overhaul,” we have determined that this imprecise compliance time would not address the identified unsafe condition in a timely manner. In developing an appropriate compliance time for this proposed AD, we considered not only the manufacturer's recommendation, but also the degree of urgency associated with addressing the subject unsafe condition, the average utilization of the affected fleet, and the time necessary to perform the modifications. In light of all of these factors, we find a compliance time of 36 months for completing the proposed actions to be warranted, in that it represents an appropriate interval of time for affected airplanes to continue to operate without compromising safety. This compliance time has been coordinated with the manufacturer.

Cost of Compliance

There are about 958 airplanes of the affected design in the worldwide fleet. This proposed AD would affect about 169 airplanes of U.S. registry. The proposed actions would take about 1 work hour per door, at an average labor rate of $65 per work hour.

The following table provides the estimated costs for U.S. operators to comply with this proposed AD.

Estimated Costs

Model	Work hours	Parts costs	Cost per airplane	Number of U.S.-registered airplanes	Fleet cost
747-100, -100B, -100B SUD, -200B, and -200C series airplanes, identified as Group 1 in Boeing Service Bulletin 747-25-3279	12	$34,832 (2 each: doors 1, 2, 4, 5, upper deck, and two-piece off-wing)	$35,612	53	$1,887,436
747-200B and -300 series airplanes, identified as Group 2 in Boeing Service Bulletin 747-25-3279	8	26,368 (2 each: doors 1, 2, 4, and 5)	26,888	4	107,552
747-200B series airplanes, identified as Group 3 in Boeing Service Bulletin 747-25-3279	10	30,600 (2 each: doors 1, 2, 4, 5, and two-piece off-wing)	31,250	1	31,250
747-100, -100B, -100B SUD, -200B, 747SP, and 747SR series airplanes, identified as Group 4 in Boeing Service Bulletin 747-25-3279	10	30,600 (2 each: doors 1, 2, 4, and 5, and upper deck)	31,250	17	531,250
747-200F and -400F series airplanes, identified as Group 5 in Boeing Service Bulletin 747-25-3279	2	4,232 (2 upper deck doors)	4,362	32	139,584
747-200B series airplanes, identified as Group 6 in Boeing Service Bulletin 747-25-3279	2	4,232 (2 two-piece off-wing doors)	4,362	0	0
747-400 and -400D series airplanes, identified in Boeing Service Bulletin 747-25-3232	2	8,250 (2 single-piece off-wing doors)	8,380	59	494,420
747-200B series airplanes, identified as Group 4 in Boeing Service Bulletin 747-25-3279 and also identified in Boeing Service Bulletin 747-25-3232	10	30,600 (2 each: doors 1, 2, 4, 5, upper deck, and single-piece off-wing)	31,250	3	93,750

Authority for This Rulemaking

The FAA's authority to issue rules regarding aviation safety is found in Title 49 of the United States Code. 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.

This rulemaking is promulgated 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 AD.

Regulatory Findings

We have 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 that the 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.

We prepared a regulatory evaluation of the estimated costs to comply with this proposed AD. See the ADDRESSES section for a location to examine the regulatory evaluation.

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 airworthiness directive (AD):

Boeing: Docket No. FAA-2005-21184; Directorate Identifier 2004-NM-111-AD.

Comments Due Date

(a) The Federal Aviation Administration (FAA) must receive comments on this AD action by June 27, 2005.

Affected ADs

(b) None.

Applicability

(c) This AD applies to the airplanes listed in Table 1 of this AD, certificated in any category.

Table 1.—Applicability

Boeing—	As identified in—
Model 747-100, -100B, -100B SUD, -200B, -200C, -200F, -300, -400F, 747SP, and 747SR series airplanes	Boeing Service Bulletin 747-25-3279, Revision 1, dated July 11, 2002.
Model 747-200B, -200C, -300, -400, and -400D series airplanes	Boeing Service Bulletin 747-25-3232, dated July 6, 2000.

Unsafe Condition

(d) This AD was prompted by a report of 30-to 60-second delays in the inflation of escape slides/rafts. We are issuing this AD to prevent actuation delays in the inflation systems of the escape slides/rafts, which could result in delayed or failed deployment of escape slides/rafts during emergency evacuation of an airplane.

Compliance

(e) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.

Modification for Upper Deck, Two-Piece Off-Wing, and Door 1, 2, 4, and 5 Slides and Slide/Rafts

(f) For Model 747-100, -100B, -100B SUD, -200B, -200C, -200F, -300, -400F, 747SP, and 747SR series airplanes identified in Boeing Service Bulletin 747-25-3279, Revision 1, dated July 11, 2002: Within 36 months after the effective date of this AD, do the actions specified in paragraphs (f)(1) and (f)(2) of this AD, as applicable, in accordance with Boeing Service Bulletin 747-25-3279, Revision 1, dated July 11, 2002.

(1) Modify the inflation systems of the upper deck and two-piece off-wing escape slides.

(2) Modify the inflation systems of the door 1, 2, 4, and 5 escape slides/rafts, as applicable.

Note 1:

Boeing Service Bulletin 747-25-3279 refers to Goodrich Service Bulletin 4A3037-25-327, dated November 30, 2001; Goodrich Service Bulletin 4A3056-25-331, dated December 21, 2001; and Goodrich Service Bulletin 4A3221-25-332, dated December 21, 2001; as additional sources of service information for doing the modifications.

Modification for Single-Piece Off-Wing Ramp/Slides

(g) For Model 747-200B, -200C, -300, -400, and -400D series airplanes identified in Boeing Service Bulletin 747-25-3232, dated July 6, 2000: Within 36 months after the effective date of this AD, modify the inflation system of the single-piece off-wing escape ramps/slides, in accordance with Boeing Service Bulletin 747-25-3232, dated July 6, 2000.

Note 2:

Boeing Service Bulletin 747-25-3232 refers to Goodrich Service Bulletin 4A3416-25-305, Revision 2, dated October 15, 2001, as an additional source of service information for doing the modification.

Parts Installation

(h) As of the effective date of this AD, unless the regulator assembly of the inflation system has been modified in accordance with paragraph (f) or (g) of this AD, as applicable, no person may install on any airplane a regulator assembly with any of the following part numbers (P/Ns): P/N 4A3047, -2, -3, -4, -5, -8, -9, or -10; P/N 4A3194-1, -2, -3, or -4; or P/N 4A3474-3.

Credit for Previous Service Bulletin

(i) Actions done before the effective date of this AD in accordance with Boeing Service Bulletin 747-25-3279, dated May 16, 2002, are acceptable for compliance with the corresponding requirements of paragraph (f) of this AD.

Alternative Methods of Compliance (AMOCs)

(j) The Manager, Seattle Aircraft Certification Office, FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19.

Issued in Renton, Washington, on May 4, 2005.

Kalene C. Yanamura,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.