[Federal Register Volume 64, Number 227 (Friday, November 26, 1999)]
[Rules and Regulations]
[Pages 66368-66370]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-30516]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-260-AD; Amendment 39-11432; AD 99-24-08]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737-100, -200, -300, -400, 
and -500 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

-----------------------------------------------------------------------

SUMMARY: This amendment supersedes an existing airworthiness directive 
(AD), applicable to all Boeing Model 737-100, -200, -300, -400, and -
500 series airplanes, that currently requires, for certain airplanes, 
repetitive replacements of the airplane battery with a new or 
reconditioned battery and replacement of the battery charger with a new 
or serviceable battery charger; performing repetitive tests to 
determine the condition of a certain diode of the Generator Control 
Units (GCU); and corrective actions, if necessary. This amendment adds, 
for certain other airplanes, a requirement for repetitive replacements 
of the airplane battery with a new or reconditioned battery, and 
clarifies a diode test requirement. This amendment is prompted by an 
incident during which all electrical power was lost due to a 
combination of a weak or depleted battery and the failure of a certain 
diode of the GCU. The actions specified in this AD are intended to 
prevent failure of all electrically powered airplane systems, which 
could result in the inability to continue safe flight and landing.

DATES: Effective December 13, 1999.
    The incorporation by reference of Boeing Telex Message M-7200-99-
01528, dated March 5, 1999, as listed in the regulations, was approved 
previously by the Director of the Federal Register as of September 16, 
1999 (64 FR 47656, September 1, 1999).
    Comments for inclusion in the Rules Docket must be received on or 
before January 25, 2000.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 99-NM-260-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056.
    The service information referenced in this AD 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; or at 
the Office of the Federal Register, 800 North Capitol Street, NW., 
suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Stephen S. Oshiro, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, FAA, Transport Airplane 
Directorate, Seattle Aircraft Certification Office, 1601 Lind Avenue, 
SW., Renton, Washington 98055-4056; telephone (425) 227-2793; fax (425) 
227-1181.

SUPPLEMENTARY INFORMATION: On August 24, 1999, the FAA issued AD 99-18-
17, amendment 39-11283 (64 FR 47656, September 1, 1999), applicable to 
all Boeing Model 737-100, -200, -300, -400, and -500 series airplanes, 
to require repetitive replacements of the airplane battery with a new 
or reconditioned battery and, for certain airplanes, replacement of the 
battery charger with a new or serviceable battery charger. That action 
also requires performing repetitive tests to determine the condition of 
a certain diode of the Generator Control Units (GCU); and corrective 
actions, if necessary. That action was prompted by an incident during 
which all electrical power was lost due to a combination of a weak or 
depleted battery and the failure of a certain diode of the GCU. The 
actions required by that AD are intended to prevent failure of all 
electrically powered airplane systems, which could result in the 
inability to continue safe flight and landing.

Actions Since Issuance of Previous Rule

    Following the incident described previously in which all electrical 
power was lost due to a weak or depleted battery and the failure of 
certain GCU diodes, an assessment of airplane battery maintenance was 
conducted. As a result, it was determined that some operators have 
extended maintenance intervals beyond those recommended by the airplane 
manufacturer, which increases the likelihood of allowing an airplane to 
operate with a weak or depleted airplane battery. In addition, the risk 
associated with the use of such a battery is greater on Model 737-100 
and -200 series airplanes because some of these airplanes use an older 
version of battery charger. The older version has charging 
characteristics that are not compatible with the extended airplane 
battery maintenance intervals.
    Since the issuance of AD 99-18-17, the FAA has determined that it 
is necessary to revise certain requirements of that AD. The FAA points 
out that its intent in that AD was to require operators of Model 737-
100 and -200 series airplanes equipped with battery chargers having 
Boeing part number (P/N) 10-60701-3, as well as P/N 10-60701-1, to 
replace the airplane battery with a new or reconditioned airplane 
battery. However, the replacement requirement for airplanes equipped 
with a battery charger having Boeing P/N 10-60701-3 was inadvertently 
omitted from paragraph (a) of the AD. That requirement is included in 
paragraph (f) of this AD.
    The FAA also has determined that it is necessary to clarify its 
intent in AD 99-18-17 regarding the test required to determine the 
condition of diode CR910 of the GCU. Although that AD only specifies 
that ``a test'' is required, this AD clarifies that the required test 
is the ``Alternative Test of Diode CR910,'' which is specified along 
with various other tests included in Boeing Telex Message M-7200-99-
01528, dated March 5, 1999. This change is necessary because the test 
requirement specified

[[Page 66369]]

in AD 99-18-17 unintentionally allows operators the discretion to 
select from any of the various tests specified in the Boeing telex 
message. The FAA has determined that all other test methods referenced 
in that Boeing telex message are unacceptable as methods of complying 
with the requirements of this amendment.

Explanation of Requirements of Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other airplanes of this same type design, this AD 
supersedes AD 99-18-17 to continue to require, for certain airplanes, 
repetitive replacements of the airplane battery with a new or 
reconditioned battery, and replacement of the battery charger with a 
new or serviceable battery charger; performing repetitive tests to 
determine the condition of a certain diode of the GCU; and corrective 
actions, if necessary. This amendment adds, for certain airplanes, a 
requirement for repetitive replacement of the airplane battery for 
Models 737-100 and -200 series airplanes equipped with battery charger 
Boeing P/N 10-60701-3 with a new or reconditioned battery, and 
clarifies a diode test requirement. The battery replacement is required 
to be accomplished in accordance with Chapter 20-20-111 of the Boeing 
737 Airplane Maintenance Manual; and the diode test is required to be 
accomplished in accordance with the ``Alternative Test of Diode 
CR910,'' as specified in Boeing Telex Message M-7200-99-01528, dated 
March 5, 1999.

Interim Action

    Since the cause of the failures of the GCU's is under 
investigation, this is considered to be interim action until final 
action is identified, at which time the FAA may consider further 
rulemaking.

Determination of Rule's Effective Date

    Since a situation exists that requires the immediate adoption of 
this regulation, it is found that notice and opportunity for prior 
public comment hereon are impracticable, and that good cause exists for 
making this amendment effective in less than 30 days.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and, thus, was not preceded by 
notice and an opportunity for public comment, comments are invited on 
this rule. Interested persons are invited to comment on this 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 under the caption 
ADDRESSES. All communications received on or before the closing date 
for comments will be considered, and this rule may be amended in light 
of the comments received. Factual information that supports the 
commenter's ideas and suggestions is extremely helpful in evaluating 
the effectiveness of the AD action and determining whether additional 
rulemaking action would be needed.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the 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 that 
summarizes each FAA-public contact concerned with the substance of this 
AD will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this rule must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 99-NM-260-AD.'' The postcard will be date stamped and 
returned to the commenter.

Regulatory Impact

    The regulations adopted herein will not have substantial direct 
effects 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, in 
accordance with Executive Order 12612, it is determined that this final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to correct an unsafe 
condition in aircraft, and that it is not a ``significant regulatory 
action'' under Executive Order 12866. It has been determined further 
that this action involves an emergency regulation under DOT Regulatory 
Policies and Procedures (44 FR 11034, February 26, 1979). If it is 
determined that this emergency regulation otherwise would be 
significant under DOT Regulatory Policies and Procedures, a final 
regulatory evaluation will be prepared and placed in the Rules Docket. 
A copy of it, if filed, may be obtained from the Rules Docket at the 
location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends 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.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by removing amendment 39-11283 (64 FR 
47656, September 1, 1999), and by adding a new airworthiness directive 
(AD), amendment 39-11432, to read as follows:

99-24-08  Boeing: Amendment 39-11432. Docket 99-NM-260-AD. 
Supersedes AD 99-18-17, Amendment 39-11283.

    Applicability: All Model 737-100, -200, -300, -400, and -500 
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 (h)(1) 
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 failure of all electrically powered airplane systems, 
which could result in the inability to continue safe flight and 
landing, accomplish the following:

Restatement of the Requirements of AD 99-18-17

    (a) For Model 737-100 and -200 series airplanes equipped with 
battery charger Boeing part number (P/N) 10-60701-1: Within 90 days 
after September 16, 1999 (the effective date of AD 99-18-17, 
amendment 39-11283), accomplish the requirements of paragraphs 
(a)(1) and (a)(2) of this AD.
    (1) Replace the airplane battery charger with a new or 
serviceable airplane battery charger, Boeing P/N 10-60701-3, in 
accordance with Chapter 20-10-111 of the

[[Page 66370]]

Boeing 737 Airplane Maintenance Manual (AMM); and
    (2) Replace the airplane battery with a new or reconditioned 
airplane battery in accordance with Chapter 24-31-11 of the Boeing 
737 AMM. Thereafter, replace the airplane battery with a new or 
reconditioned airplane battery at intervals not to exceed 750 flight 
hours, until the accomplishment of paragraph (f) of this AD.
    (b) For Model 737-300, -400, and -500 series airplanes: Within 
90 days after September 16, 1999, replace the airplane battery with 
a new or reconditioned airplane battery in accordance with Chapter 
24-31-11 of the Boeing 737 AMM. Thereafter, replace the airplane 
battery with a new or reconditioned airplane battery at intervals 
not to exceed 750 flight hours.
    (c) For all airplanes: Within 90 days after September 16, 1999, 
perform a test to determine the condition of diode CR910 of the 
Generator Control Units (GCU), in accordance with Boeing Telex 
Message M-7200-99-01528, dated March 5, 1999.
    (1) If all diodes pass the test, repeat the diode test 
thereafter at intervals not to exceed 600 flight hours, until the 
accomplishment of paragraph (g) of this AD.
    (2) If any diode fails the test: Prior to further flight, 
replace the GCU with a new or serviceable GCU, and the airplane 
battery with a new or reconditioned airplane battery, and repeat the 
diode test for the replaced GCU in accordance with the telex message 
until successful completion of the test is achieved. Repeat the 
diode test thereafter, at intervals not to exceed 600 flight hours, 
until the accomplishment of paragraph (g) of this AD.
    (d) As of September 16, 1999, no person shall install a battery 
charger having Boeing P/N 10-60701-1 on any Model 737 series 
airplane.
    (e) Within 10 days after accomplishing the initial diode test 
required by paragraph (c) of this AD, submit a report of the test 
results (negative findings, i.e., test failures) to the Manager, 
Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane 
Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; 
fax (425) 227-1181. Information collection requirements contained in 
this regulation have been approved by the Office of Management and 
Budget (OMB) under the provisions of the Paperwork Reduction Act of 
1980 (44 U.S.C. 3501 et seq.) and have been assigned OMB Control 
Number 2120-0056.

New Requirements of this AD

    (f) For Model 737-100 and -200 series airplanes equipped with 
battery charger Boeing P/N 10-60701-3: Within 90 days after the 
effective date of this AD, or within 750 flight hours after the last 
battery replacement accomplished in accordance with paragraph (a)(2) 
of this AD, whichever occurs later, replace the airplane battery 
with a new or reconditioned airplane battery in accordance with 
Chapter 24-31-11 of the Boeing 737 AMM. Thereafter, replace the 
airplane battery with a new or reconditioned airplane battery at 
intervals not to exceed 750 flight hours. Accomplishment of this 
replacement constitutes terminating action for the requirements of 
paragraph (a)(2) of this AD.
    (g) For all airplanes: Within 90 days after the effective date 
of this AD, or within 90 days after accomplishment of the test 
required by paragraph (c) of this AD, whichever occurs later, 
determine the condition of diode CR910 of the GCU, in accordance 
with the ``Alternative Test of Diode CR910,'' as specified in Boeing 
Telex Message M-7200-99-01528, dated March 5, 1999. Accomplishment 
of this action constitutes terminating action for the requirements 
of paragraph (c) of this AD.

    Note 2: Any tests performed prior to September 16, 1999, in 
accordance with Boeing Telex Message M-7200-99-01528, dated February 
19, 1999, or dated March 4, 1999, are not considered acceptable for 
compliance with the applicable action specified by this AD.

    (1) If all diodes pass the test, repeat the diode test 
thereafter at intervals not to exceed 600 flight hours.
    (2) If any diode fails the test: Prior to further flight, 
replace the GCU with a new or serviceable GCU, and the airplane 
battery with a new or reconditioned airplane battery, and repeat the 
``Alternative Test of Diode CR910'' for the replaced GCU in 
accordance with the telex message until successful completion of the 
test is achieved. Repeat the diode test thereafter, at intervals not 
to exceed 600 flight hours.

Alternative Methods of Compliance

    (h)(1) 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 ACO. 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.
    (2) Alternative methods of compliance with paragraphs (a)(1), 
(a)(2), or (b) of this AD, approved previously in accordance with AD 
99-18-17, amendment 39-11283, are approved as alternative methods of 
compliance with paragraphs (a)(1), (a)(2), or (b) of this AD.

    Note 3: 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

    (i) Special flight permits may be issued in accordance with 
Secs. 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.

Incorporation by Reference

    (j) Except as provided by paragraphs (a)(1), (a)(2), (b), and 
(f) of this AD, the actions shall be done in accordance with Boeing 
Telex Message M-7200-99-01528, dated March 5, 1999. This 
incorporation by reference was approved previously by the Director 
of the Federal Register as of September 16, 1999 (64 FR 47656, 
September 1, 1999). Copies may be obtained from Boeing Commercial 
Airplane Group, P.O. Box 3707, Seattle, Washington. Copies may be 
inspected at the FAA, Transport Airplane Directorate, 1601 Lind 
Avenue, SW., Renton, Washington; or at the Office of the Federal 
Register, 800 North Capitol Street, NW., suite 700, Washington, DC.
    (k) This amendment becomes effective on December 13, 1999.

    Issued in Renton, Washington, on November 17, 1999.
Vi L. Lipski,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 99-30516 Filed 11-24-99; 8:45 am]
BILLING CODE 4910-13-U