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Proposed Rule

Airworthiness Directives; Boeing Model 747-400, 747-400D, and 747-400F Series Airplanes

Document Details

Information about this document as published in the Federal Register.

Published Document

This document has been published in the Federal Register. Use the PDF linked in the document sidebar for the official electronic format.

Start Preamble

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking.

SUMMARY:

The FAA proposes to supersede an existing airworthiness directive (AD) that applies to all Boeing Model 747-400, -400D, and -400F series airplanes. The existing AD currently requires revising the airplane flight manual (AFM) to require the flightcrew to maintain certain minimum fuel levels in the center fuel tanks, and to prohibit the use of the horizontal stabilizer fuel tank. This proposed AD would require installing new integrated display software in the integrated display units and electronic flight instrument system/engine indication and crew alerting system interface units (EIUs) of the flight deck. This proposed AD also would require revising the AFM to include procedures to prevent dry operation of the center wing and horizontal stabilizer fuel tanks; for maintaining minimum fuel levels; and for de-fueling fuel tanks. For certain airplanes, the proposed AD also requires removing G13 pin ground wires of a certain wire integration unit of the EIUs at certain connector locations. This proposed AD results from fuel system reviews conducted by the manufacturer. We are proposing this AD to reduce the potential for ignition sources inside fuel tanks, which, in combination with flammable fuel vapors, could result in fuel tank explosions and consequent loss of the airplane.

DATES:

We must receive comments on this proposed AD by March 27, 2006.

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.
  • Fax: (202) 493-2251.
  • 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.

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

Start Further Info

FOR FURTHER INFORMATION CONTACT:

Sulmo Mariano, Aerospace Engineer, Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 917-6501; fax (425) 917-6590.

End Further Info End Preamble Start Supplemental Information

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 in the ADDRESSES section. Include the docket number “Docket No. FAA-2006-23803; Directorate Identifier 2005-NM-238-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.

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 may review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78), or may visit http://dms.dot.gov.

Examining the Docket

You may 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 (800) 647-5227) 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 Docket Management System receives them.

Discussion

The FAA has examined the underlying safety issues involved in fuel tank explosions on several large transport airplanes, including the adequacy of existing regulations, the service history of airplanes subject to those regulations, and existing maintenance practices for fuel tank systems. As a result of those findings, we issued a regulation titled “Transport Airplane Fuel Tank System Design Review, Flammability Reduction and Maintenance and Inspection Requirements” (67 FR 23086, May 7, 2001). In addition to new airworthiness standards for transport airplanes and new maintenance requirements, this rule included Special Federal Aviation Regulation No. 88 (“SFAR 88,” Amendment 21-78, and subsequent Amendments 21-82 and 21-83).

Among other actions, SFAR 88 requires certain type design (i.e., type certificate (TC) and supplemental type certificate (STC)) holders to substantiate that their fuel tank systems can prevent Start Printed Page 6405ignition sources in the fuel tanks. This requirement applies to type design holders for large turbine-powered transport airplanes and for subsequent modifications to those airplanes. It requires them to perform design reviews and to develop design changes and maintenance procedures if their designs do not meet the new fuel tank safety standards. As explained in the preamble to the rule, we intended to adopt airworthiness directives to mandate any changes found necessary to address unsafe conditions identified as a result of these reviews.

In evaluating these design reviews, we have established four criteria intended to define the unsafe conditions associated with fuel tank systems that require corrective actions. The percentage of operating time during which fuel tanks are exposed to flammable conditions is one of these criteria. The other three criteria address the failure types under evaluation: single failures, single failures in combination with another latent condition(s), and in-service failure experience. For all four criteria, the evaluations included consideration of previous actions taken that may mitigate the need for further action.

We have determined that the actions identified in this AD are necessary to reduce the potential of ignition sources inside fuel tanks, which, in combination with flammable fuel vapors, could result in fuel tank explosions and consequent loss of the airplane.

Relevant Rulemaking

On December 23, 2002, we issued AD 2002-24-52, amendment 39-12993 (68 FR 14, January 2, 2003), for all Boeing Model 747-400, -400D, and -400F series airplanes. That AD requires revising the airplane flight manual (AFM) to require the flightcrew to maintain certain minimum fuel levels in the center fuel tanks, and to prohibit the use of the horizontal stabilizer fuel tank. That AD resulted from reports indicating that two fuel pumps showed evidence of extreme localized overheating of parts in the priming and vapor pump section of the fuel pump. We issued that AD to require the flightcrew to maintain certain minimum fuel levels in the center fuel tanks, and to prohibit the use of the horizontal stabilizer fuel tank.

Other Relevant Rulemaking

We also issued the following ADs:

Other Relevant Rulemaking

AD—Requires—And—And—
2001-12-21, amendment 39-12277 (66 FR 33170, June 21, 2001)Revising the AFM to include procedures to prevent dry operation of the center wing fuel tank override/jettison pumpsFor certain airplanes, prohibits operation of the horizontal stabilizer tank transfer pumps in flightFor certain airplanes, requires installing improved fuel pumps, which terminates the AFM revision.
2001-21-07, amendment 39-12478 (66 FR 54652, October 30, 2001)For certain airplanes, revising the AFMFor all airplanes, performing repetitive inspections for wear or damage of the inlet check valves and inlet adapters of the override/jettison pumps, and doing corrective actions if necessaryReworking of certain components, which ends the repetitive inspection requirements.
2002-19-52, amendment 39-12900 (67 FR 61253, September 30, 2002)Removing currently required AFM revisions, inserting new AFM revisions, and installing placards to alert the flightcrew to the operating restrictionsProhibits installation of any uninspected pumpsPermits the AFM revision and placard to be removed under certain conditions.

Actions Since Existing ADs Were Issued

The preambles to ADs 2002-24-52 and 2002-19-52 explain that we consider the requirements “interim action” and were considering further rulemaking. We now have determined that further rulemaking is indeed necessary, and this proposed AD follows from that determination.

We have reviewed the following service bulletins:

Service Bulletins

Boeing Alert Service Bulletin—For Model—
747-31A2350, Revision 1, dated March 17, 2005747-400 and 747-400F series airplanes.
747-31A2351, Revision 1, dated March 17, 2005747-400, 747-400D, and 747-400F series airplanes.
747-31A2352, Revision 1, dated March 17, 2005747-400 and 747-400F series airplanes.

The service bulletins describe procedures for installing new integrated display software in the integrated display units (IDUs) and electronic flight instrument system (EFIS)/engine indication and crew alerting system (EICAS) interface units (EIU) of the flight deck. The new software provides new IDS EICAS fuel system messages. These messages alert the flightcrew when to shut the fuel pumps off. Accomplishing the actions specified in the service information is intended to adequately address the unsafe condition.

Each service bulletin described previously refers to Rockwell Collins Service Bulletins IDS-7000-31-49, IDS-7000-31-50, or IDS-7000-31-51; all dated June 28, 2004; as applicable; as an additional source of service information for installing the new software.

FAA's Determination and Requirements of the Proposed AD

We have evaluated all pertinent information and identified an unsafe condition that is likely to develop on other airplanes of the same type design. For this reason, we are proposing this AD, which would supersede AD 2002-24-52 to continue to require revising the AFM to require the flightcrew to maintain certain minimum fuel levels in Start Printed Page 6406the center fuel tanks, and to prohibit the use of the horizontal stabilizer fuel tank. The proposed AD also would require:

  • Accomplishing the actions specified in the Boeing service information described previously;
  • Revising the Limitations section of the AFM to include procedures to prevent dry operation of the center wing and horizontal stabilizer fuel tanks; for maintaining minimum fuel levels; and for de-fueling fuel tanks; and
  • For certain airplanes: Removing G13 pin ground wires of the wire integration unit on the E2-6 electronic shelf of the left, center, and right electronics interface units at certain connector locations.

After installing the new software and incorporating the new AFM revisions, the AFM revision required by AD 2002-24-52 and certain AFM revisions required by ADs 2001-12-21, 2001-21-07, and 2002-19-52 may be removed.

Change to Existing AD

This proposed AD would retain all the requirements of AD 2002-24-52. Since AD 2002-24-52 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:

Revised Paragraph Identifiers

Requirement in AD 2002-24-52Corresponding requirement in this proposed AD
paragraph (a)paragraph (g).
paragraph (b)paragraph (h).

Costs of Compliance

There are about 520 airplanes of the affected design in the worldwide fleet. The following table provides the estimated costs for U.S. operators to comply with this proposed AD.

Estimated Costs

ActionWork hoursAverage labor rate per hourPartsCost per airplaneNumber of U.S.-registered airplanesFleet cost
AFM revision (required by AD 2002-24-52)1$65None$65101$6,565.
Installation of new IDS software (new proposed action)365$100295101$29,795.
Removal of G-13 pin ground wires (new proposed action)165None650$65 if an affected airplane is imported and placed on the U.S. Register in the future.
AFM revision (new proposed action)165None65101$6,565.

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 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 and placed it in the AD docket. See the ADDRESSES section for a location to examine the regulatory evaluation.

Start List of Subjects

List of Subjects in 14 CFR Part 39

End List of Subjects

The Proposed Amendment

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

Start Part

PART 39—AIRWORTHINESS DIRECTIVES

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

Start Authority

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

End Authority
[Amended]

2. The Federal Aviation Administration (FAA) amends § 39.13 by removing amendment 39-12993 (68 FR 14, January 2, 2003) and adding the following new airworthiness directive (AD):

Boeing: Docket No. FAA-2006-23803; Directorate Identifier 2005-NM-238-AD.

Comments Due Date

(a) The FAA must receive comments on this AD action by March 27, 2006.

Affected ADs

(b) This AD supersedes AD 2002-24-52. In addition, after accomplishing the requirements of paragraphs (h) and (k) of this AD, the airplane flight manual (AFM) Start Printed Page 6407requirements specified in table 1 of this AD may be removed.

Table 1.—Affected ADs

AFM requirements of—Of—
(1) Paragraph (a)AD 2001-12-21, amendment 39-12277.
(2) Paragraph (a)AD 2001-21-07, amendment 39-12478.
(3) Paragraph (c)AD 2002-19-52, amendment 39-12900.
(4) Paragraphs (f) and (g)This AD.

Applicability

(c) This AD applies to airplanes identified in table 2 of this AD, certificated in any category.

Table 2.—Applicability

Boeing model—As identified in Boeing Service Bulletin—
(1) 747-400, 747-400D, and 747-400F series airplanes747-31A2351, Revision 1, dated March 17, 2005.
(2) 747-400 and 747-400F series airplanes747-31A2350, Revision 1, dated March 17, 2005.
(3) 747-400 and 747-400F series airplanes747-31A2352, Revision 1, dated March 17, 2005.

Unsafe Condition

(d) This AD results from fuel system reviews conducted by the manufacturer. We are issuing this AD to reduce the potential for ignition sources inside fuel tanks, which, in combination with flammable fuel vapors, could result in fuel tank explosions and consequent loss of the 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.

Restatement of Requirements of AD 2002-24-52

Airplane Flight Manual (AFM) Revision

(f) Within 4 days after receipt of emergency AD 2002-24-51, instead of complying with the requirements of paragraph (d) of AD 2002-24-51, revise the Limitations section of the AFM to include the following (this may be accomplished by inserting a copy of this AD into the AFM):

CERTIFICATE LIMITATIONS

Fueling and use of the horizontal stabilizer tank (if installed) is prohibited.

The center wing tank (CWT) must contain a minimum of 17,000 pounds (7,700 kilograms) prior to engine start, if the CWT override/jettison pumps are to be selected ON during flight.

The CWT fuel quantity indication system must be operative to dispatch with CWT mission fuel.

Both CWT override/jettison pump switches must be selected OFF at or before CWT fuel quantity reaches 7,000 pounds (3,200 kilograms), if CWT fuel quantity is less than 50,000 pounds (22,700 kilograms) prior to engine start. The CWT override pumps may be selected ON during stabilized cruise conditions. Both CWT override/jettison pump switches must be selected OFF at or before the CWT fuel quantity reaches 3,000 pounds (1,400 kilograms).

Note:

With CWT override/jettison pumps selected OFF and CWT fuel quantity greater than 6,000 pounds (2,800 kilograms), the FUEL OVRD CTR L & R EICAS messages will be displayed. Do not accomplish the associated non-normal procedure.

Both CWT override/jettison pump switches must be selected OFF at or before CWT fuel quantity reaches 3,000 pounds (1,400 kilograms), if CWT fuel quantity is greater than or equal to 50,000 pounds (22,700 kilograms) prior to engine start.

Both CWT override/jettison pumps must be selected OFF when either CWT override/jettison fuel pump low pressure light illuminates.

Warning: Do not reset a tripped fuel pump circuit breaker.

Warning: Do not cycle CWT override/jettison pump switches from ON to OFF to ON with any continuous low pressure indication present.

Note:

The center wing tank may be emptied normally during an emergency fuel jettison.

Note:

In a low fuel situation, both CWT override/jettison pumps may be selected ON and all CWT fuel may be used.

If a center wing tank pump fails with fuel in the center tank, accomplish the FUEL OVRD CTR L, R non-normal procedure.

If the main tanks are not full, the zero fuel gross weight of the airplane plus the weight of CWT tank fuel may exceed the maximum zero fuel gross weight by up to 7,000 pounds (3,200 kilograms) for takeoff, climb, cruise, descent, and landing, provided that the effects of balance (CG) have been considered.

When defueling any fuel tanks, the Fuel Pump Low Pressure indication lights must be monitored and the fuel pumps positioned to OFF at the first indication of fuel pump low pressure. Defueling with passengers on board is prohibited.

The limitations contained in this AD supersede any conflicting basic airplane flight manual limitations.”

(g) If an operator has already complied with AD 2002-24-51, it can comply with paragraph (f) of this AD by deleting the phrase “if a placard prohibiting its use is installed” from the first paragraph of the AFM revision required by paragraph (d) of AD 2002-24-51.

New Actions Required by This AD

Installation of New Integrated Display System (IDS) Software

(h) Within 6 months after the effective date of this AD, install new IDS software in the integrated display units and electronic flight instrument system/engine indication and crew alerting system interface units of the flight deck, in accordance with the Accomplishment Instructions of the applicable service bulletin in table 3 of this AD.

Table 3.—Revision 1 of Service Bulletins

For model—Boeing service bulletin—
(1) 747-400, 747-400D, and 747-400F series airplanes747-31A2351, Revision 1, dated March 17, 2005.
(2) 747-400 and 747-400F series airplanes747-31A2350, Revision 1, dated March 17, 2005.
Start Printed Page 6408
(3) 747-400 and 747-400F series airplanes747-31A2352, Revision 1, dated March 17, 2005.

Note 1:

Each service bulletin identified in table 3 of this AD refers to Rockwell Collins Service Bulletins IDS-7000-31-49, IDS-7000-31-50, or IDS-7000-31-51; all dated June 28, 2004; as applicable; as an additional source of service information for installing the new IDS software.

(i) Installing new IDS software before the effective date of this AD in accordance with the applicable service bulletin in table 4 of this AD, is acceptable for compliance with the requirements of paragraph (h) of this AD.

Table 4.—Original Service Bulletins

For model—Boeing service bulletin—
(1) 747-400, 747-400D, and 747-400F series airplanes747-31A2351, dated September 3, 2004.
(2) 747-400 and 747-400F series airplanes747-31A2350, dated September 3, 2004.
(3) 747-400 and 747-400F series airplanes747-31A2352, dated September 3, 2004.

Removal of Pin Ground Wires

(j) For airplanes on which FR-HiTEMP fuel pumps have been incorporated in accordance with Boeing Service Bulletin 747-28-2258, dated December 19, 2003; or Revision 1, dated August 11, 2005: Before further flight after installing the new IDS software required by paragraph (h) of this AD, remove the G13 pin ground wires of the wire integration unit on the E2-6 electronic shelf of the left, center, and right electronics interface units, that correspond to the connector locations in table 5 of this AD, in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA. Chapter 20-41-03 of the Boeing 747-400 Aircraft Maintenance Manual is one approved method.

Table 5.—Connector Location

ConnectorLocation
DM7353CALeft EIU.
DM7352CACenter EIU.
DM7351CARight EIU.

AFM Revision

(k) Concurrently with the requirements of paragraph (h) of this AD, revise the Limitations section of the AFM to include the following (this may be done by inserting a copy of this AD into the AFM):

Certification Limitations

Center Wing Tank (CWT): The CWT fuel quantity indication system must be operative to dispatch with CWT mission fuel.

The CWT must contain a minimum of 17,000 pounds (7,700 kilograms) prior to engine start, if the CWT override/jettison pumps are to be selected ON during takeoff.

If the FUEL LOW CTR L or R message is displayed both CWT override/jettison pumps must be selected OFF.

If the FUEL PRESS CTR L or R message is displayed, the corresponding CWT override/jettison pump must be selected OFF.

Horizontal Stabilizer Tank (HST): The following additional limitations must be followed if the HST is fueled and used:

The HST fuel quantity indication system must be operative to dispatch with HST mission fuel.

If the FUEL PMP STB L or R message is displayed while on the ground both HST pumps must be selected OFF.

If the FUEL LOW STAB L or R message is displayed in flight the corresponding HST pump must be selected OFF.

If the FUEL PRESS STAB L or R is displayed the corresponding HST pump must be selected OFF.

The remaining fuel in the HST must be considered unusable, and the effects of that unusable fuel on balance (CG) must be considered.

Warning: Do not reset a tripped fuel pump circuit breaker.

Defueling: Prior to defueling any fuel tanks, perform a lamp test of the respective Fuel Pump Low Pressure indication lights. When defueling, the Fuel Pump Low Pressure indication lights must be monitored and the fuel pumps positioned to OFF at the first indication of fuel pump low pressure. When defueling with passengers on board, fuel pump switches must be selected OFF at or above approximately 7,000 pounds (3,200 kilograms) for the CWT, 3,000 pounds (1,400 kilograms) for main tanks, and 2,100 pounds (1,000 kilograms) for the HST.

Alternative Methods of Compliance (AMOCs)

(l)(1) The Manager, Seattle ACO, FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19.

(2) Before using any AMOC approved in accordance with § 39.19 on any airplane to which the AMOC applies, notify the appropriate principal inspector in the FAA Flight Standards Certificate Holding District Office.

Start Signature

Issued in Renton, Washington, on January 30, 2006.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.

End Signature End Part End Supplemental Information

[FR Doc. E6-1682 Filed 2-7-06; 8:45 am]

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