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###### Department of Transportation

###### Federal Aviation Administration 

          - 14 CFR Part 39 
          - [Docket No. 99-NM-163-AD] 
          - RIN 2120-AA64 

# AGENCY:

Federal Aviation Administration, DOT. 

# ACTION:

Notice of proposed rulemaking (NPRM). 

# SUMMARY:

This document proposes the supersedure of an existing airworthiness directive (AD), applicable to all Boeing Model 777 series airplanes, that currently requires repetitive testing of the engine fire shutoff switch (EFSS) to determine if the override mechanism and the switch handle are operational, and replacement of the EFSS, if necessary. That AD also requires, for certain airplanes, installation of a collar on a specific circuit breaker of the standby power management panel, and installation of placards to advise the flightcrew that the override mechanism must be pushed in order to pull the fire switch. That AD was prompted by a report indicating that a solenoid and an override mechanism of the EFSS were not operational due to overheating of the solenoid. The actions specified by the proposed AD are intended to prevent damage to the EFSS solenoid and to the override mechanism, and consequent failure of the EFSS due to overheating of the solenoid; such failure could result in the inability of the flightcrew to discharge the fire extinguishing agent in the event of an engine fire. This action would add various actions that would terminate the repetitive testing requirements. 

# DATES:

Comments must be received by July 3, 2000. 

# ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 99-NM-163-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal holidays. 

The service information referenced in the proposed rule may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington. 

# FOR FURTHER INFORMATION CONTACT:

Larry Reising, Aerospace Engineer, Propulsion Branch, ANM-140S, FAA, Transport Airplane Directorate, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-2683; fax (425) 227-1181. 

# SUPPLEMENTARY INFORMATION:

## Comments Invited 

Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this notice may be changed in light of the comments received. 

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket. 

                    Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this notice must submit a self-addressed, stamped                           ( print page 31838)                        postcard on which the following statement is made: “Comments to Docket Number 99-NM-163-AD.” The postcard will be date stamped and returned to the commenter.                 

## Availability of NPRMs 

Any person may obtain a copy of this NPRM by submitting a request to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 99-NM-163-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. 

## Discussion 

On May 5, 1997, the FAA issued AD 97-10-11, amendment 39-10023 (62 FR 25837, May 12, 1997), applicable to all Boeing Model 777 series airplanes, to require repetitive testing of the engine fire shutoff switch (EFSS) to determine if the override mechanism and the switch handle are operational, and replacement of the EFSS, if necessary. That AD also requires, for certain airplanes, installation of a collar on a specific circuit breaker of the standby power management panel, and installation of placards to advise the flightcrew that the override mechanism must be pushed in order to pull the fire switch. That action was prompted by a report indicating that a solenoid and an override mechanism of the EFSS were not operational due to overheating of the solenoid. The actions specified by that AD are intended to prevent damage to the EFSS solenoid and to the override mechanism due to overheating of the solenoid; such failure of the EFSS could result in the inability of the flightcrew to discharge the fire extinguishing agent in the event of an engine fire. 

## Actions Since Issuance of Previous Rule 

In the preamble to AD 97-10-11, the FAA specified that the actions required by that AD were considered “interim action” and that once a final action is identified, the FAA may consider additional rulemaking action. The FAA has determined that further rulemaking action is indeed necessary; this proposed AD follows from that determination. 

## Explanation of Relevant Service Information 

The FAA has reviewed and approved Boeing Alert Service Bulletin 777-26A0009, dated October 23, 1997. The service bulletin describes procedures for activating the circuit breaker C26612 in the P310 panel; removing the placards in the flight compartment; and replacing the EFSS with a new EFSS. Accomplishment of these actions eliminates the need for repetitive testing of the EFSS required by AD 97-10-11. Accomplishment of the actions specified in the service bulletin is intended to adequately address the identified unsafe condition. 

## Explanation of Requirements of Proposed Rule 

Since an unsafe condition has been identified that is likely to exist or develop on other products of this same type design, the proposed AD would supersede AD 97-10-11 to continue require repetitive testing of the EFSS to determine if the override mechanism and the switch handle are operational, and replacement of the EFSS, if necessary. The proposed AD also would continue to require, for certain airplanes, installation of a collar on a specific circuit breaker of the standby power management panel, and installation of placards to advise the flightcrew that the override mechanism must be pushed in order to pull the fire switch. In addition, the proposed AD would require accomplishment of the actions specified in the service bulletin described previously, except as discussed below. 

## Differences Between the Proposed AD and the Service Bulletin 

Operators should note that the effectivity listing of Boeing Alert Service Bulletin 777-26A0009 affects airplanes having line positions 1 through 93 inclusive. The FAA has determined that, although the engine fire control switches, part number (P/N) 233W6201-1, and P/N's S231W263-1 and -2, were installed on affected airplanes during manufacture, it may be possible that these switches have been installed on Model 777 series airplanes during maintenance activities. Therefore, the FAA has determined that the applicability of the proposed AD would affect all Model 777 series airplanes. 

## Cost Impact 

There are approximately 196 airplanes of the affected design in the worldwide fleet. The FAA estimates that 48 airplanes of U.S. registry would be affected by this proposed AD. 

The actions that are currently required by AD 97-10-11, and retained in this proposed AD, take approximately 1 work hour per airplane to accomplish, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the currently required actions on the U.S. operators is estimated to be $2,880, or $60 per airplane, per testing cycle. 

The new actions that are proposed in this AD action would take approximately 1 work hour per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts would cost approximately $4,054 per airplane. Based on these figures, the cost impact of the new proposed requirements of this AD on U.S. operators is estimated to be $197,472, or $4,114 per airplane. 

The cost impact figures discussed above is based on assumptions that no operator has yet accomplished any of the current or proposed requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted. 

## Regulatory Impact 

The regulations proposed herein 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. Therefore, it is determined that this proposal would not have federalism implications under Executive Order 13132. 

                    For the reasons discussed above, I certify that 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) if promulgated, 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. A copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption                     **ADDRESSES.**

# List of Subjects in 14 CFR Part 39

      - Air transportation
      - Aircraft
      - Aviation safety
      - Safety

## The Proposed Amendment 

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend part 39 of the Federal Aviation Regulations (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 

2. Section 39.13 is amended by removing amendment 39-10023 (62 FR 25837, May 12, 1997), and by adding a new airworthiness directive (AD), to read as follows: 
      ( print page 31839)    
**Boeing:**                                 Docket 99-NM-163-AD. Supersedes AD 97-10-11, Amendment 39-10023.                             

*Applicability:*                                 All Model 777 series airplanes, certificated in any category.                             

# Note 1:

This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (e) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

*Compliance:*                                 Required as indicated, unless accomplished previously.                             

To prevent damage to the engine fire shutoff switch (EFSS) solenoid and to the override mechanism, and consequent failure of the EFSS, which could result in the inability of the flightcrew to discharge the fire extinguishing agent in the event of an engine fire, accomplish the following: 

## Restatement of Actions Required by AD 97-10-11 

### Repetitive Testing of the EFSS 

(a) For all airplanes: Within 14 days after May 27, 1997 (the effective date of AD 97-10-11, amendment 39-10023), perform a test of the EFSS of both the left-and right-hand engines to determine if the override mechanism and the switch handle are operational, in accordance with Boeing Alert Service Bulletin 777-26A0012, dated May 1, 1997. 

(1) If the override mechanism and the switch handle of the EFSS are operational, prior to further flight, accomplish the requirements of paragraph (a)(1)(i) or (a)(1)(ii) of this AD, as applicable, in accordance with the alert service bulletin. 

(i) For Group 1 airplanes identified in the alert service bulletin: Install a collar on circuit breaker C26612 of panel P310 of the standby power management panel. Following accomplishment of this installation, prior to further flight, install placards near the EFSS of both engines and near the auxiliary power unit (APU) EFSS to advise the flightcrew that the override mechanism must be pushed in order to pull the fire switch. 

(ii) For Group 2 airplanes identified in the alert service bulletin: Ensure that a collar is installed on circuit breaker C26612 of panel P310 of the standby power management panel. If a collar is not installed, prior to further flight, install a collar on circuit breaker C26612 of panel P310 of the standby power management panel. 

(2) If the override mechanism or the switch handle of the EFSS is not operational, prior to further flight, replace the EFSS with a new or serviceable EFSS, in accordance with the alert service bulletin. 

(b) For all airplanes: Repeat the requirements of paragraph (a) of this AD thereafter at intervals not to exceed 500 flight hours. 

## New Actions Required by This AD 

### Terminating Action 

(c) For all airplanes: Within 2 years after the effective date of this AD, accomplish the actions specified in paragraphs (c)(1), (c)(2), and (c)(3) of this AD in accordance with Boeing Alert Service Bulletin 777-26A0009, dated October 23, 1997. Accomplishment of all three actions constitutes terminating action for the repetitive testing requirements of paragraph (b) of this AD. 

(1) Replace the engine fire control module. 

(2) Activate the circuit breaker C26612 in the P310 panel. 

(3) Remove the placards in the flight compartment. 

### Spares 

(d) As of the effective date of this AD, no person shall install an engine fire control module, part number (P/N) 233W6201-1, or engine fire switches P/N S231W263-1 or -2, on any airplane. 

### Alternative Methods of Compliance 

(e) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Seattle ACO. 

# Note 2:

Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO.

### Special Flight Permits 

(f) Special flight permits may be issued in accordance with §§ 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished.

Issued in Renton, Washington, on May 15, 2000. 

Donald L. Riggin, 

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. 

[FR Doc. 00-12674 Filed 5-18-00; 8:45 am] 

BILLING CODE 4910-13-P