Airworthiness Directives; McDonnell Douglas Model DC-9 and DC-9- 80 Series Airplanes, and Model MD-88 Airplanes

DEPARTMENT OF TRANSPORTATION

14 CFR Part 39

[Docket No. 95-NM-214-AD; Amendment 39-9798; AD 96-22-10]

RIN 2120-AA64

Airworthiness Directives; McDonnell Douglas Model DC-9 and DC-9-

80 Series Airplanes, and Model MD-88 Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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

SUMMARY: This amendment adopts a new airworthiness directive (AD),

applicable to all McDonnell Douglas DC-9 and DC-9-80 series airplanes,

and Model MD-88 airplanes, that requires repetitive leak checks of the

lavatory drain system and repair, if necessary; provides for the option

of revising the FAA-approved maintenance program to include a schedule

of leak checks; requires the installation of a cap on the flush/fill

line; and requires replacement or modification of the vent system

piping. This amendment is prompted by continuing reports of damage to

engines and airframes, separation of engines from airplanes, and damage

to property on the ground, caused by ``blue ice'' that forms from

leaking lavatory drain systems on transport category airplanes and

subsequently dislodges from the airplane fuselage. The actions

specified by this AD are intended to prevent such damage associated

with the problems of ``blue ice.''

DATES: Effective December 11, 1996. The incorporation by reference of

certain publications listed in the regulations is approved by the

Director of the Federal Register as of December 11, 1996.

ADDRESSES: The service information referenced in this AD may be

obtained from McDonnell Douglas Corporation, 3855 Lakewood Boulevard,

Long Beach, California 90846, Attention: Technical Publications

Business Administration, Department C1-L51 (2-60). This information may

be examined at the Federal Aviation Administration (FAA), Transport

Airplane Directorate, Rules Docket, 1601 Lind Avenue, SW., Renton,

Washington; or at the FAA, Transport Airplane Directorate, Los Angeles

Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood,

California; or at the Office of the Federal Register, 800 North Capitol

Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Walter Eierman, Aerospace Engineer,

Systems and Equipment Branch, ANM-130L, FAA, Los Angeles Aircraft

Certification Office, 3960 Paramount Boulevard, Lakewood, California

90712; telephone (310) 627-5336; fax (310) 627-5210.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal

Aviation Regulations (14 CFR part 39) to include an airworthiness

directive (AD) that is applicable to all McDonnell Douglas DC-9 and DC-

9-80 series airplanes, and Model MD-88 airplanes was published in the

Federal Register on December 26, 1995 (60 FR 66764). That action

proposed to:

1. require repetitive leak checks of the lavatory drain system and

repair, if necessary;

2. provide for the option of revising the FAA-approved maintenance

program to include a schedule of leak checks;

3. require the installation of a cap on the flush/fill line; and

4. require replacement or modification of the vent system piping.

Interested persons have been afforded an opportunity to participate

in the making of this amendment. Due consideration has been given to

the comments received.

Support for the Proposal

Two commenter support the proposed rule.

Request to Exclude All-Cargo Configured Airplanes from

Applicability

One commenter requests that the applicability of the proposal be

revised to exclude airplanes operating in an all-cargo configuration,

where lavatories and lavatory fill/drain systems have been removed.

The FAA concurs. This final rule requires leak checks of the

lavatory/fill drain system. However, if no such system is installed on

the airplane then, obviously, the requirements of the AD cannot be

performed and, likewise, should not be required. As long as there is

one lavatory drainage system installed on the airplane, the

requirements of this AD would still apply. To make this eminently clear

to affected operators, the FAA has revised the applicability of the

final rule to clarify that the AD applies to airplanes that are

equipped with a lavatory drainage system.

Request for Permission to Use Alternative Check Valves on Flush/

Fill Line

Two commenters request that the proposed rule be revised to allow

the use of Monogram 4803-86 series check valves on flush/fill lines as

an alternative to the specified lever/lock cap. These commenters point

out that Monogram check valves with similar design characteristics were

approved previously by the FAA as an acceptable alternative item for

compliance with a similar proposed AD that is applicable to Boeing

Model 737 series airplanes [reference Docket No. 95-NM-111-AD (60 FR

55673, November 2, 1995)].

The FAA concurs with these commenters' request. Paragraphs (a)(5),

(b)(3), and (d) of the final rule have been revised to specify this.

Additionally, paragraphs (a)(5) and (b)(3) of the final rule have been

revised to provide the necessary instructions for replacing the O-rings

associated with the Monogram 4803-86 series check valve, and for

testing the check valve for proper operation.

Request to Increase Leak Check Interval for Certain Shaw Aero

Valves

One commenter requests that proposed paragraphs (a)(2) and

(b)(2)(ii) be revised to allow the following Shaw Aero valves to be

leak checked at 1,000-hour intervals:

331 series, all serial numbers

332 series, all serial numbers

The commenter states that these valves have been accepted previously by

the FAA for a 1,000-hour leak check interval either in accordance with

AD 94-23-10, which is applicable to Boeing

[[Page 57305]]

Model 727 series airplanes; or a similar proposed rule applicable to

Boeing Model 737 series airplanes (reference Docket No. 95-NM-111-AD).

The FAA concurs. Paragraphs (a)(2) and (b)(2)(ii) of this final

rule have been revised to include these part-numbered valves in the

requirements for leak checks at 1,000-hour intervals.

Request to Increase Leak Check Interval for Certain Kaiser Valves

One commenter requests that the proposed repetitive leak check

interval of 1,000 hours for Kaiser valves having part numbers 0218-0026

and 0218-0032, be increased to 1,500 hours. As justification for this

request, the commenter submits qualification and test data.

The FAA cannot concur, since insufficient data were submitted to

support a longer inspection interval. Paragraph (g) of the final rule

provides guidance as to the specific type of data needed to justify

extensions to the leak check intervals set forth in this AD.

Two other commenters request that the proposed repetitive leak

check interval of 1,500 hours for Kaiser valves having part number

2651-329 series, be increased to 4,500 hours. These commenters state

that the longer interval has been proposed for this same valve in

another proposed AD that is applicable to Boeing Model 737 series

airplanes (reference Docket No. 95-NM-111-AD).

The FAA concurs with these commenters' request, since this valve

previously was found to be acceptable for a 4,500-hour leak check

interval. Paragraph (a)(1) of this final rule has been revised

accordingly.

Request to Increase Leak Check Interval for Certain Pneudraulics

Valves

One commenter requests that the proposed leak check interval of

1,000 hours for Pneudraulics valves having part number 9527, be

increased to 2,000 hours. The commenter states that, to date, it has

accumulated over 580,000 flight hours using this Pneudraulics valve on

its fleet of airplanes, and there have been only two cases of leaking

reported. In both cases, the valves were inspected and found to be

serviceable without repair. This in-service experience should justify a

longer repetitive check interval.

The FAA does not concur, since insufficient data were submitted to

support a longer inspection interval. Paragraph (g) of the final rule

provides guidance as to the specific type of data needed to justify

extensions to the leak check intervals set forth in this AD.

Request to Revise Procedure for Dump Valve Leak Check

One commenter requests that the proposed rule be revised to change

the procedure for conducting a dump valve leak check so that less fluid

can be used. This commenter points out that NOTE 2 of the proposal

states that this leak check is to be accomplished with water/rinsing

fluid to a level at least 4 inches above the flapper in the bowl.

However, the commenter notes that this is 2 inches more fluid than is

needed for similar leak checks of Boeing Model 727 series airplanes

required by AD 94-23-10 [amendment 39-9073 (59 FR 59124, November 16,

1994)]. The commenter maintains that the same level of fluid should be

used so that all leak checks are standardized for all airplanes.

The FAA does not concur with the commenter's request. The procedure

to fill the toilet bowl to 4 inches above the flapper (approximately

\1/2\ full) is also meant to check the tank and the rinse line check

valves. The FAA finds that performing the test using less fluid does

not do as complete and adequate a job as is necessary to meet the

intent of this AD.

Request for Clarification of Leak Check Procedures

One commenter considers that proposed paragraphs (a)(2)(i) and

(a)(2)(ii) contradict each other. The former paragraph would require

that both the inner door/closure device and the outer cap/door must be

leak checked; while the latter paragraph states that, in lieu of

pressure testing, the outer seal and seal surface may be visually

inspected for damage on service panel valves that have an inner seal.

The commenter states that, to leak check the outer cap, maintenance

personnel will have to remove the inner seal, thus ruining the seal in

the process, and there is no guarantee that the tests would be

performed in a particular sequence to avoid this. The commenter

contends that a leak check on the outer seal would negate the test on

the inner seal, and that only a visual inspection of the outer seal is

necessary.

The FAA does not concur with the commenters statement that the two

paragraphs contradict each other. Paragraph (a)(2)(i) calls for a leak

check of each closure device. For certain types of service panel

valves, paragraph (a)(2)(ii) merely provides an alternative to that

leak check, since it states that an inspection of the seal may be

performed in lieu of the leak check; that paragraph does not require

that both actions be performed.

Request for Procedures for Performing Leak Check of Lavatory Vent

System

One commenter requests that proposed paragraph (e), which would

require a leak check of the lavatory vent system, be revised to include

procedures for how these leak checks are to be performed.

The FAA concurs that inclusion of such procedures is necessary.

NOTE 2 has been revised to add this information, and a new NOTE 7 has

been included, which also contains these procedures.

Request to Delete Alternative Visual Inspections

One commenter requests that the proposal be revised to delete the

alternative that would allow operators only to visually inspect the

cover (outer) seal of lavatory drain valves for wear or damage, rather

than to leak check them. This commenter considers it important that

leak testing of the drain valves should be performed both on the

internal portions of the valve and on the cap portions of the valve as

well. This commenter states that one of the primary emphases of

addressing the problems of blue ice has been the need for a dual

sealing valve; by using a dual sealing valve, the reliability of a

drain valve is doubled, and the potential for blue ice incidents is

significantly reduced. However, if the FAA would permit only a visual

inspection of the outer seal, rather than an actual leak test, the

benefit of the dual sealing valve is lost and safety is compromised

because ``the potential for a failure through the outer seal that has

not been tested rises exponentially as it is not being tested.'' The

commenter considers that the only reason for allowing the visual

inspection (rather than a leak test) is to provide a cost savings to

the airlines.

The FAA does not concur with the commenter's request to delete the

provision for the alternative procedure. The maintenance procedures

required by this final rule, as well as the intervals at which

maintenance is required, were developed in consideration of the design

and known service experience of the many designs used in lavatory

systems. The alternative procedure for the visual inspection is allowed

based on the fact that some valves have an inner seal that is closed

when the outer cap is closed; for this type of valve, leakage from the

outer cap could only be checked if the inner seal were removed since,

when the inner seal is correctly in place, it will prevent any fluid

from reaching the outer cap seal. It is for this type of valve that the

AD provides the

[[Page 57306]]

alternative to allow operators to inspect the seal and seal surface of

the outer cap seal in lieu of performing a leak check of the outer

seal. The FAA's ultimate determination with regard to this provision

was not made to provide a cost savings to airlines (as suggested by the

commenter), but to allow procedures to be accomplished that will

provide an acceptable level of safety.

Request to Increase Leak Checks at Flush/Fill Port

One commenter considers that an upstream device with positive shut-

off and anti-siphon features would eliminate the ``blue ice'' that

occurs at the flush/fill port. The commenter considers that, until such

time as a new device can be tested and approved, the leak checks and

inspections of that port should be increased. As further indication of

a need for more inspections, the commenter states that the currently

installed flush/fill caps and lever lock cap can be damaged or removed

by maintenance personnel; additional inspections would ensure that

these discrepancies are identified and corrected in a timely manner.

The FAA does not concur with the commenter's request. The FAA

considers that action is necessary at this time to improve leakage

conditions at the flush/fill port. The lever lock cap required by this

AD action will contribute to this goal by being less likely to be left

unclosed, more difficult to remove, and less prone to falling off, than

the conventional turn cap. While other suitable devices currently may

be under development, the FAA finds no justification for delaying this

AD action while waiting for their availability. However, as those

devices become available, the FAA may consider requests for the use of

them as alternative methods of compliance, under the provisions of

paragraph (g) of this final rule. As for the inspections intervals, the

FAA developed them based on the best data obtainable to date; however,

if blue ice originating from this leak path becomes increasingly

problematic, the FAA may consider further rulemaking to adjust the

inspection interval as appropriate.

Request to Require Same Maintenance Program for All Operators

One commenter requests that any future extensions of leak check

intervals should be based on performance of the hardware involved, not

on the performance of an individual operator's maintenance program.

This commenter requests that the FAA consider requiring the same

maintenance program (relative to the leak checks) for all operators; an

individual maintenance program should not influence the leak check

extensions that the FAA gives to any particular valve. While it is

important to have a proper maintenance program to ensure reliability of

the aircraft and the lavatory system, the commenter considers it more

important to realize that a quality valve (regardless of the

maintenance program) is what increases reliability--not the

``maintenance program'' itself. A quality valve is not affected by the

service personnel. The best of maintenance programs can be compromised

for any number of reasons due to necessary human involvement; however,

hardware, if properly designed has a built-in safe integrity.

The FAA does not concur with the commenter's request. The FAA

considers that hardware design and maintenance are both factors in the

effective prevention of leakage at the lavatory service panel. This AD

has been structured to give ``credit'' for both of these factors in

determining appropriate leak check intervals. Although the FAA could

require the same maintenance program of all airlines, it recognizes

that varying aspects of each airlines' operational environment and the

human factors associated with maintenance procedures means that equal

results for all airlines would not necessarily result. This AD allows

airlines who have proven, effective maintenance programs to obtain

``credit'' (i.e., in the form of increased leak check intervals) for

their programs.

Request to Require Leak Checks of All Outer Cap/Door Seals

One commenter requests that the proposal be revised to require that

all seals that could potentially come into contact with the effluent

that causes blue ice be leak tested. The commenter points specifically

to proposed paragraph (b)(2)(iii), which states that, if an operator

uses ``donut'' -type valves, both the donut and the outer cap/door seal

must be leak checked. Other provisions of the proposed rule, however,

would require only a visual inspection of the outer cap/door seal on

other types of valves. This commenter states that it is not in the best

interest of eliminating blue ice not to leak check every seal.

The FAA acknowledges this commenter's concern, and does not

disagree with the suggestion that testing every seal could lower the

possibility of the formation of blue ice. It is obvious that more

testing, either by testing of every seal or by increasing the frequency

of tests, theoretically could reduce the potential for blue ice to

occur. However, in this AD, the FAA has attempted to establish a

reasonable test program for each configuration of valve, in

consideration of the unique design of the individual valve assemblies

and the service history data relative to each valve. The FAA has

determined that the program set forth in this AD will achieve an

acceptable level of safety with regard to the problems associated with

blue ice.

Request to Require that ``Donut'' Assemblies Be Removed from

Service

One commenter requests that the proposal be revised to require that

all ``donut''-type valve assemblies be removed from service. This

commenter contends that this type of valve has a long history of poor

performance, and it is commonplace for the ``donut'' component of the

valve not to be installed (missing), thereby rendering the valve

inoperative. The commenter states that during ground service, the donut

component sometimes washes into the lavatory service cart and is not

replaced into the lavatory drain panel valve until the next inspection.

The commenter maintains that blue ice will continue to fall if ``this

archaic approach to valve technology continues to be used.''

The FAA does not concur with the commenter's request. The FAA

acknowledges that the ``donut'' design is neither the latest in

technology standards nor the most effective valve assembly. However,

based on the best data obtainable to date, the FAA has determined that

a leak check of ``donut''-type valve assemblies at intervals of 200

flight hours will ensure that the valve is monitored adequately to

provide an acceptable level of safety. [This leak check requirement is

stated in paragraph (a)(4) of the final rule.] The FAA is continuing to

review the on-going service history of these valves, and may consider

further rulemaking to require their removal from service if future data

justify such an action.

Request to Require Standard Nomenclature for Primary vs. Secondary

Seals

One commenter requests that the FAA require all valve manufacturers

to use standard nomenclature for primary and secondary seals. This

commenter asserts that the first seal that the effluent comes in

contact with should be referred to as the ``primary'' seal; the cover

seal should be referred to as the ``secondary'' seal. This commenter

states that certain valve manufacturers have begun to call the cover

seal on their valves ``primary'' seals. This can create problems, since

[[Page 57307]]

paragraph (b)(2)(i)(B) of the proposal would require that the outer

cap/door seal is only visually inspected and, thus, the ``primary''

seal on this manufacturer's assemblies is never pressure tested. The

commenter maintains that the FAA should not allow the primary seal to

go untested.

The FAA acknowledges this commenter's concerns, but finds that no

change to the AD is necessary. The FAA does not control the

nomenclature that manufacturers choose to identify seals in their valve

assemblies; further, the FAA does not consider it appropriate that what

a manufacturer chooses to call a seal should be used to determine the

actions required by this AD. The FAA finds that the wording used in the

requirement for the visual inspection is very specific as to which

component of the valve assembly is to be inspected (the service panel

drain valve outer cap/door seal and the inner seal if the valve has an

inner door/closure device with a second positive seal). The requirement

deliberately does not contain the words ``primary'' or ``secondary'' in

referring to seals, since those terms are not specific and, as the

commenter points out, are used differently by different manufacturers.

Request to Revise Data Collection Guidance

One commenter requests that the data collection guidance iterated

in proposed paragraph (c) be revised. Specifically, the commenter asks

that language contained in proposed paragraph (c)(8) that refers to

removal of debris done as part of maintenance be modified to reflect

more specifically what occurs during normal ground servicing. The

commenter states that normally the only debris that is removed during

ground servicing is what could be called ``major'' blockage items;

simple things, such as toilet paper or other minor debris, are left in

place as part of normal ground maintenance. In light of this, the

tested condition from which data is gathered should represent the

condition that the system would be in during normal operations. The

commenter requests that paragraph (c)(8) be changed to specify this.

The FAA concurs. The commenter's suggested revision will provide

useful clarification of the intent of the requirement. Paragraph (c)(8)

of the final rule has been revised to specify that only major blockages

should be removed prior to a leak check test, and that minor debris

removal that is not commonly removed during normal ground maintenance

check should not be removed prior to the leak check.

Request Not to Consider Test Data with Drain Valves Below Ball

Valves

One commenter requests that proposed paragraph (c) be revised to

specify that test data on a panel valve that is below a ball valve is

not valid data, and that such data should not be included in any test

data submitted to the FAA for purposes of requesting an increase in a

leak check interval for any valve. This commenter states that a panel

valve below a ball valve would not be subject to the same operational

requirements as a panel valve without a ball valve ahead of it in the

drain line, as the highly reliable ball valve would always be stopping

any leaks.

The FAA concurs. A panel valve installation with a ball valve is

not subject to the same operating environment as an panel valve

installation without a ball valve. Therefore, any data collected on the

former type of valve installation would not be valid as justification

for an extended leak check interval for the latter type of valve

installation. To clarify this, the FAA has revised NOTE 9 of the final

rule (which addressed collecting data for leak check intervals) to

include information indicating that the configuration of the entire

drain system on the airplanes used in evaluating a drain valve leak

check interval should be defined. This way, it can be assured that the

data submitted is representative of the applications where the drain

valve will be used.

Conclusion

After careful review of the available data, including the comments

noted above, the FAA has determined that air safety and the public

interest require the adoption of the rule with the changes previously

described. The FAA has determined that these changes will neither

increase the economic burden on any operator nor increase the scope of

the AD.

Cost Impact

There are approximately 2,097 Model DC-9 and DC-9-80 series

airplanes and Model MD-88 airplanes of the affected design in the

worldwide fleet. The FAA estimates that 1,191 airplanes of U.S.

registry and 47 U.S. operators, will be affected by this AD.

1. Leak checks. It will take approximately 4 work hours per

airplane lavatory drain to accomplish each leak check, at an average

labor cost of $60 per work hour. There normally are 2 drains per

airplane. Depending upon the type of valves installed and the flight

utilization rate of the airplane, an airplane subject to this AD could

be required to be inspected as few as 2 times per year or as many as 15

times per year. Based on these figures, the cost impact of the leak

check requirement on U.S. operators will be between $960 and $7,200 per

airplane per year.

2. Inspections. Should an operator elect to perform the inspection

of the service panel drain valve cap/door seal and seal mating surface,

the inspection will take approximately 1 work hour to accomplish, at an

average labor cost of $60 per work hour. Depending upon the type of

valves installed and the flight utilization rate of the airplane, an

airplane subject to this AD could be required to be inspected as few as

2 times per year or as many as 15 times per year. Based on these

figures, the cost impact of the inspection requirement on U.S.

operators will be between $120 and $1,800 per airplane per year.

3. Installation of cap on flush/fill line. The proposed

installation will take approximately 2 work hours to accomplish, at an

average labor cost of $60 per work hour. The cost of required parts is

estimated to be $275 per flush/fill line. There are normally 3 flush/

fill lines per airplane. Based on these figures, the cost impact of the

proposed installation requirement on U.S. operators will be $1,411,335,

or $1,185 per airplane.

4. Installation of lavatory vent system replacement/modification.

The portion of this installation that entails modification of the

toilet assembly will require between 2 and 4 work hours per airplane to

accomplish, depending on the brand of toilet involved. The average

labor cost is estimated to be $60 per work hour. The cost of required

parts is estimated to be between $83 and $2,121 per airplane. Based on

these figures, the cost impact of this portion of the required

installation on U.S. operators will be between $203 and $2,361 per

airplane.

The portion of this installation that entails modification of

lavatory vent lines will require between 15 and 52 work hours per

airplane to accomplish, depending upon the configuration of the

airplane, if certain other modifications have already been

accomplished, and the modification option selected. The average labor

cost is estimated to be $60 per work hour. The cost of required parts

is estimated to be between $600 and $13,000 per airplane. Based on

these figures, the cost impact of this portion of the required

installation on U.S. operators will be between $1,500 and $16,120 per

airplane.

The number of required work hours, as indicated above, is presented

in this discussion as if the actions required by this AD were to be

conducted as ``stand

[[Page 57308]]

alone'' actions. However, in actual practice, these actions could be

accomplished coincidentally or in combination with normally scheduled

airplane inspections and other maintenance program tasks. Therefore,

the actual number of necessary ``additional'' work hours will be

minimal in many instances. Additionally, any costs associated with

special airplane scheduling should be minimal.

In addition to the costs discussed above, for those operators who

elect to comply with proposed paragraph (b) of this AD action, the FAA

estimates that it will take approximately 40 work hours per operator to

incorporate the lavatory drain system leak check procedures into the

maintenance programs, at an average labor cost of $60 per work hour.

Based on these figures, the cost impact of the maintenance revision

requirement of this AD on U.S. operators is estimated to be $2,400 per

operator.

The ``cost impact'' figure discussed above is based on assumptions

that no operator has yet accomplished any of the 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 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.

For the reasons discussed above, I certify that this action (1) is

not a ``significant regulatory action'' under Executive Order 12866;

(2) is not a ``significant rule'' under 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. A final evaluation has been prepared for this action

and it is contained in the Rules Docket. A copy of it 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 adding the following new

airworthiness directive:

96-22-10 McDonnell Douglas: Amendment 39-9798. Docket 95-NM-214-AD.

Applicability: All Model DC-9-10, -20, -30, -40, and -50 series

airplanes; Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83),

and DC-9-87 (MD-87) series airplanes; and Model MD-88 airplanes;

equipped with a lavatory drainage system; 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 (g) 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 engine damage, airframe damage, and/or hazard to

persons or property on the ground as a result of ``blue ice'' that

has formed from leakage of the lavatory drain system and dislodged

from the airplane, accomplish the following:

Note 2: The leak checks of the toilet dump valve, flush/fill

line, and lavatory vent system that are required by this AD may be

performed by filling the toilet tank with water/rinsing fluid to a

level at least 4 inches above the flapper in the bowl, and checking

for leakage after a period of 5 minutes.

(a) Except as provided in paragraph (b) of this AD, accomplish

the applicable procedures specified in paragraphs (a)(1), (a)(2),

(a)(3), (a)(4), (a)(5), and (a)(6) of this AD. If the individual

waste drain system panel incorporates more than one type of valve,

the inspection interval that applies to that panel is determined by

the component with the longest inspection interval allowed. Each of

the components must be inspected or tested at that time at each

service panel location.

(1) For each lavatory drain system that has an in-line drain

valve installed, Kaiser Electroprecision part number series 2651-

329: Within 4,500 flight hours after the effective date of this AD,

and thereafter at intervals not to exceed 4,500 flight hours,

accomplish the procedures specified in paragraphs (a)(1)(i) and

(a)(1)(ii) of this AD:

(i) Conduct a leak check of the dump valve (in-tank valve that

is spring loaded closed and operable by a T-handle at the service

panel), and the in-line drain valve. The in-line drain valve leak

check must be performed with a minimum of 3 pounds per square inch

differential pressure (PSID) applied across the valve.

(ii) Visually inspect the service panel drain valve outer cap

seal and the inner seal (if the valve has an inner door/closure

device with a second positive seal), and the seal mating surfaces,

for wear or damage that may allow leakage.

(2) Within 1,000 flight hours after the effective date of this

AD, and thereafter at intervals not to exceed 1,000 flight hours,

accomplish the applicable procedures specified in paragraphs

(a)(2)(i) and (a)(2)(ii) of this AD for each lavatory drain system

with a service panel drain valve installed that is listed in Table

1, below:

Table 1.--Valves Requiring Leak Checks at 1,000--Flight Hour Intervals

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

Manufacturer Part No. Serial No.

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

Shaw Aero Devices........................ 10101000C-A (or higher dash All serial numbers.

number).

Shaw Aero Devices........................ 10101000B-A (or higher dash All serial numbers.

number).

Shaw Aero Devices........................ 10101B-577-1............... All serial numbers.

Shaw Aero Devices........................ 10101B-577-2............... All serial numbers.

Shaw Aero Devices........................ 331 series................. All serial numbers.

Shaw Aero Devices........................ 332 series................. All serial numbers.

Pneudraulics............................. 9527 series................ All serial numbers.

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

[[Page 57309]]

(i) Conduct a leak check of the dump valve and the service panel

drain valve. The service panel drain valve leak check must be

performed with a minimum of 3 PSID applied across the valve. Both

the inner door/closure device and the outer cap/door must be leak

checked.

(ii) For service panel valves that have an inner seal: In lieu

of pressure testing, the outer cap seal and seal surface may be

visually inspected for damage or wear.

(3) For each lavatory drain system that has a service panel

drain valve installed, Shaw Aero Devices part number series

10101000C [except as specified in paragraph (a)(2) of this AD], or

Shaw Aero Devices part number 10101000B [except as specified in

paragraph (a)(2) of this AD]: Within 600 flight hours after the

effective date of this AD, and thereafter at intervals not to exceed

600 flight hours, accomplish the procedures specified in paragraphs

(a)(3)(i) and (a)(3)(ii) of this AD, on each:

(i) Conduct a leak check of the dump valve and the service panel

drain valve. The service panel drain valve leak check must be

performed with a minimum of 3 PSID applied across the valve. Both

the inner door/closure device and the outer cap/door must be leak

checked.

(ii) For service panel valves that have an inner seal: In lieu

of pressure testing, the outer cap seal and seal surface may be

visually inspected for damage or wear.

(4) For other lavatory drain systems not addressed in paragraph

(a)(1), (a)(2), or (a)(3) of this AD: Within 200 flight hours after

the effective date of this AD, and thereafter at intervals not to

exceed 200 flight hours, accomplish the procedures specified in

paragraphs (a)(4)(i) and (a)(4)(ii) of this AD:

(i) Conduct a leak check of the dump valve and the service panel

drain valve. The service panel drain valve leak check must be

performed with a minimum of 3 PSID applied across the valve. Both

the inner door/closure device and the outer cap/door must be leak

checked.

(ii) For service panel valves that have an inner seal: In lieu

of pressure testing, the outer cap seal and seal surface may be

visually inspected for damage or wear.

(5) For flush/fill lines: Within 5,000 flight hours after the

effective date of this AD, and thereafter at intervals not to exceed

5,000 flight hours, accomplish the procedures specified in either

paragraph (a)(5)(i) or (a)(5)(ii) of this AD, as appropriate for the

airplane's flush/fill line installation:

(i) For airplanes equipped with a flush/fill line cap,

accomplish either paragraph (a)(5)(i)(A) or (a)(5)(i)(B):

(A) Conduct a leak check of the flush/fill line cap. This leak

check must be made with a minimum of 3 PSID applied across the cap.

Or

(B) Replace the seals on the toilet tank anti-siphon (check)

valve and in the flush/fill line cap. Additionally, perform a leak

check of the toilet tank anti-siphon (check) valve with a minimum of

3 PSID across the valve after changing the seals.

(ii) For airplanes equipped with a check valve vacuum breaker,

Monogram part number 4803-86 series: Replace the O-rings/seals in

the valve and test the check valve and vacuum breaker sections of

the valve for proper operation, in accordance with the

manufacturer's component maintenance/overhaul manual.

(6) As a result of the leak checks and inspections required by

this paragraph, or if evidence of leakage is found at any other

time, accomplish the requirements of either paragraph (a)(6)(i),

(a)(6)(ii) or (a)(6)(iii) as applicable:

(i) If a leak is discovered, prior to further flight, repair the

leak. Prior to further flight after repair, perform the leak test.

Additionally, prior to returning the airplane to service, clean the

surfaces adjacent to where the leakage occurred to clear them of any

horizontal fluid residue streaks; such cleaning must be to the

extent that any future appearance of a horizontal fluid residue

streak will be taken to mean that the system is leaking again.

Note 3: For purposes of this AD, ``leakage'' is defined as any

visible leakage observed during a leak test; the presence of ice in

the service panel; or horizontal fluid residue streaks or ice trails

originating at the service panel. The fluid residue is usually, but

not necessarily, blue in color.

(ii) If any worn or damaged seal is found, or if any damaged

seal mating surface is found, prior to further flight, repair or

replace it in accordance with the valve manufacturer's maintenance

manual.

(iii) In lieu of performing the requirements of paragraph

(a)(6)(i) or (a)(6)(ii): Prior to further flight, drain the affected

lavatory system and placard the lavatory inoperative until repairs

can be accomplished.

(b) As an alternative to the requirements of paragraph (a) of

this AD: Within 180 days after the effective date of this AD, revise

the FAA-approved maintenance program to include the requirements

specified in paragraphs (b)(1), (b)(2), (b)(3), (b)(4), (b)(5),

(b)(6), and (b)(7) of this AD:

(1) Replace the valve seals in accordance with the applicable

schedule specified in paragraphs (b)(1)(i) and (b)(1)(ii) of this

AD. Any revision to this replacement schedule must be approved by

the Manager, Los Angeles Aircraft Certification Office (ACO), FAA,

Transport Airplane Directorate.

(i) For each lavatory drain system that has an in-line drain

valve installed, Kaiser Electroprecision part number series 2651-

329: Replace the seals within 5,000 flight hours after revision of

the maintenance program in accordance with paragraph (b) of this AD,

and thereafter at intervals not to exceed 52 months.

(ii) For each lavatory drain system that has any other type of

drain valve: Replace the seals within 5,000 flight hours after

revision of the maintenance program in accordance with paragraph (b)

of this AD, and thereafter at intervals not to exceed 18 months.

(2) Conduct periodic leak checks of the lavatory drain systems

in accordance with the applicable schedule specified in paragraphs

(b)(2)(i), (b)(2)(ii), (b)(2)(iii), and (b)(2)(iv) of this AD. If

the individual waste drain system incorporates more than one type of

valve, the interval that applies to that system is determined by the

component with the longest inspection interval allowed. Each of the

components in that system must be inspected/tested at that time. Any

revision to this leak check schedule must be approved by the

Manager, Los Angeles ACO, FAA, Transport Airplane Directorate.

(i) For each lavatory drain system that has an in-line drain

valve, Kaiser Electroprecision part number series 2651-329: Within

5,000 flight hours after revision of the maintenance program in

accordance with paragraph (b) of this AD, and thereafter at

intervals not to exceed 24 months or 5,000 flight hours, whichever

occurs later, accomplish the procedures specified in paragraphs

(b)(2)(i)(A) and (b)(2)(i)(B) of this AD:

(A) Conduct a leak check of the dump valve (in-tank valve that

is spring loaded closed and operable by a T-handle at the service

panel) and the in-line drain valve. The in-line drain valve leak

check must be performed with a minimum of 3 PSID applied across the

valve.

(B) Visually inspect the service panel drain valve outer cap/

door seal and the inner seal (if the valve has an inner door/closure

device with a second positive seal) and seal mating surface for wear

or damage that may cause leakage. Any worn or damaged seal must be

replaced and any damaged seal mating surface must be repaired or

replaced, prior to further flight, in accordance with the valve

manufacturer's maintenance manual.

(ii) Within 1,000 flight hours after revising the maintenance

program in accordance with paragraph (b) of this AD, and thereafter

at intervals not to exceed 1,000 flight hours, accomplish the

procedures specified in paragraphs (b)(2)(ii)(A) and (b)(2)(ii)(B)

of this AD for each lavatory drain system that has a service panel

drain valve installed that is listed in Table 2 of this AD:

Table 2.--Valves Requiring Leak Checks at 1,000-Flight Hour Intervals

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

Manufacturer Part No. Serial No.

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

Shaw Aero Devices........................ 10101000C.................. All serial numbers.

Shaw Aero Devices........................ 10101000B.................. All serial numbers.

Shaw Aero Devices........................ 331 series................. All serial numbers.

Shaw Aero Devices........................ 332 series................. All serial numbers.

Pneudraulics............................. 9527 series................ All serial numbers.

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

[[Page 57310]]

(A) Conduct leak checks of the dump valve and the service panel

drain valve. The service panel drain valve leak check must be

performed with a minimum of 3 PSID applied across the valve. Only

the inner door/closure device of the service panel drain valve must

be leak checked.

(B) Visually inspect the service panel drain valve outer cap/

door seal and seal mating surface for wear or damage that may cause

leakage.

(iii) For each lavatory drain system that has a lavatory drain

system valve that incorporates only an outer cap seal (i.e., uses no

inner flapper), or that incorporates an inner seal that is not an

attached part of the valve (i.e., a ``donut''): Within 200 flight

hours after revising the maintenance program in accordance with

paragraph (b) of this AD, and thereafter at intervals not to exceed

200 flight hours, conduct leak checks of the dump valve and the

service panel drain valve. The service panel drain valve leak check

must be performed with a minimum 3 PSID applied across the valve.

Both the donut and the outer cap/door must be leak checked.

(iv) For each lavatory drain system that incorporates any other

type of approved valve(s): Within 400 flight hours after revising

the maintenance program in accordance with paragraph (b) of this AD,

and thereafter at intervals not to exceed 400 flight hours,

accomplish the procedures specified in paragraphs (b)(2)(iv)(A) and

(b)(2)(iv)(B) of this AD:

(A) Conduct leak checks of the dump valve and the service panel

drain valve. The service panel drain valve leak check must be

performed with a minimum 3 PSID applied across the valve. If the

service panel drain valve has an inner door/closure device with a

second positive seal, only the inner door must be leak checked.

(B) If the valve has an inner door/closure device with a second

positive seal: Visually inspect the service panel drain valve outer

door/cap seal and seal mating surface for wear or damage that may

cause leakage.

(3) For flush/fill lines: Within 5,000 flight hours after the

effective date of this AD, and thereafter at intervals not to exceed

5,000 flight hours, accomplish the procedures specified in either

paragraph (b)(3)(i) or (b)(3)(ii) of this AD, as applicable:

(i) For airplanes equipped with a flush/fill line cap,

accomplish either paragraph (b)(3)(i)(A) or (b)(3)(i)(B):

(A) Conduct a leak check of the flush/fill line cap. This leak

check must be made with a minimum of 3 PSID applied across the cap.

Or

(B) Replace the seals on the toilet tank anti-siphon (check)

valve and the flush/fill line cap. Additionally, perform a leak

check of the toilet tank anti-siphon (check) valve with a minimum of

3 PSID across the valve after changing the seals.

(ii) For airplanes equipped with a check valve vacuum breaker,

Monogram part number 4803-86 series: Replace the O-rings/seals in

the valve and test the check valve and vacuum breaker sections of

the valve for proper operation, in accordance with the

manufacturer's component maintenance/overhaul manual.

(4) Provide procedures for accomplishing visual inspections to

detect leakage of the lavatory waste drain line and lavatory flush/

fill line, at each waste service panel, to be conducted by

maintenance personnel at intervals not to exceed 4 calendar days or

45 flight hours, whichever occurs later.

(5) Provide procedures for reporting leakage. These procedures

shall provide that any ``horizontal blue streak'' findings must be

reported to maintenance and that, prior to further flight, the

leaking system shall either be repaired, or be drained and placarded

inoperative.

(i) For systems incorporating an in-line drain valve, Kaiser

Electroprecision part number series 2651-329: The reporting

procedures must include provisions for reporting to maintenance any

instances of abnormal operation of the valve handle for the in-line

drain valve, as observed by service personnel during normal

servicing.

(A) Additionally, for these systems, these provisions must

include procedures for either: Prior to further flight, following

the in-line drain valve manufacturer's recommended troubleshooting

procedures and correction of the discrepancy; or prior to further

flight, draining the lavatory system and placarding it inoperative

until the correction of the discrepancy can be accomplished.

(B) If the drain system also includes an additional service

panel drain valve, Shaw Aero Devices part number 10101000C-A (or

higher dash number); or Shaw Aero Devices part number 10101000B-A

(or higher dash number); or Shaw Aero Devices part number 10101B-

577-1 or 10101B-577-2; or Pneudraulics part number series 9527:

Indications of abnormal operation of the valve handle for the in-

line drain valve need not be addressed immediately if a leak check

of the service panel drain valve indicates no leakage or other

discrepancy. In these cases, repair of the in-line drain valve must

be accomplished within 1,000 flight hours after the leak check of

the additional service panel drain valve.

(6) Provide training programs for maintenance and servicing

personnel that include information on ``Blue Ice Awareness'' and the

hazards of ``blue ice.''

(7) As a result of the leak checks and inspections required by

this paragraph, or if evidence of leakage is found at any other

time, accomplish the requirements of either paragraph (b)(7)(i),

(b)(7)(ii) or (b)(7)(iii), as applicable:

(i) If a leak is discovered, prior to further flight, repair the

leak. Prior to further flight after repair, perform the leak test.

Additionally, prior to returning the airplane to service, clean the

surfaces adjacent to where the leakage occurred to clear them or any

horizontal fluid residue streaks; such cleaning must be to the

extent that any future appearance of a horizontal fluid residue

streak will be taken to mean that the system is leaking again.

Note 4: For purposes of this AD, ``leakage'' is defined as any

visible leakage observed during a leak test; the presence of ice in

the service panel; or horizontal fluid residue streaks/ice trails

originating at the service panel. The fluid residue is usually, but

not necessarily, blue in color.

(ii) If any worn or damaged seal is found, or if any damaged

seal mating surface is found, prior to further flight, repair or

replace it in accordance with the valve manufacturer's maintenance

manual.

(iii) In lieu of performing the requirements of paragraph

(b)(7)(i) or (b)(7)(ii): Prior to further flight, drain the affected

lavatory system and placard the lavatory inoperative until repairs

can be accomplished.

(c) For operators who elect to comply with paragraph (b) of this

AD: Any revision to (i.e., extension of) the leak check intervals

required by paragraph (b) of this AD must be approved by the

Manager, Los Angeles ACO, FAA, Transport Airplane Directorate.

Requests for such revisions must be submitted to the Manager of the

Los Angeles ACO through the FAA Principal Maintenance Inspector

(PMI), and must include the following information:

(1) The operator's name;

(2) A statement verifying that all known cases/indications of

leakage or failed leak tests are included in the submitted material;

(3) The type of valve (make, model, manufacturer, vendor part

number, and serial number);

(4) The period of time covered by the data;

(5) The current FAA leak check interval;

(6) Whether or not seals have been replaced between the seal

replacement intervals required by this AD;

(7) Whether or not leakage has been detected between leak check

intervals required by this AD, and the reason for leakage (i.e.,

worn seals, foreign materials on sealing surface, scratched or

damaged sealing surface or valve, etc.); and

(8) Whether or not any leak check was conducted without first

inspecting or cleaning the sealing surfaces, changing the seals, or

repairing the valve. [If such activities have been accomplished

prior to conducting the periodic leak check, that leak check shall

be recorded as a ``failure'' for purposes of the data required for

this request submission. The exception to this is the normally

scheduled seal change in accordance with paragraph (b)(1) of this

AD. Performing this scheduled seal change immediately prior to a

leak check will not cause that leak check to be recorded as a

failure.] The leak check is meant to be performed with the valve in

the condition it would be in when in normal service. Only major

blockages need be removed prior to a leak check. Minor debris that

is not commonly removed during normal ground maintenance should not

be removed prior to the leak check.

Note 5: Requests for approval of revised leak check intervals

may be submitted in any format, provided that the data give the same

level of detail specified in paragraph (c) of this AD.

Note 6: For the purposes of expediting resolution of requests

for revisions to the leak check intervals, the FAA suggests that the

requester summarize the raw data; group the data gathered from

different airplanes (of the same model) and drain systems with the

same kind of valve; and provide a recommendation from pertinent

industry group(s) and/or the manufacturer specifying an appropriate

revised leak check interval.

[[Page 57311]]

(d) For all airplanes: Within 5,000 flight hours after the

effective date of this AD, accomplish the requirements of either

paragraph (d)(1) or (d)(2) of this AD:

(1) Install a lever/lock cap on the flush/fill lines at each

lavatory service panel. The cap must be either an FAA-approved

lever/lock cap, or a cap installed in accordance with McDonnell

Douglas DC-9 Service Bulletin 38-47, dated April 17, 1992. Or

(2) Install a Monogram 4803-86 series check valve on the flush/

fill lines for all lavatory service panels.

(e) For only those airplanes listed in McDonnell Douglas DC-9

Service Bulletin 38-41, Revision 3, dated July 5, 1994: Accomplish

the procedures specified in paragraphs (e)(1) and (e)(2) of this AD:

(1) Conduct leak checks of the lavatory vent system at the same

time as conducting the leak checks of the dump valve and flush/fill

line required by this AD. If a leak is discovered, prior to further

flight, accomplish the procedures specified in either paragraph

(e)(1)(i), (e)(1)(ii), (e)(1)(iii), or (e)(1)(iv) of this AD:

Note 7: The leak check of the lavatory vent system should be

performed with a minimum of 3 pounds per square inch differential

pressure (PSID) across the vent system. This leak check may be

performed by filling the toilet tank with water/rinsing fluid to a

level at least 4 inches above the flapper in the bowl, and checking

for leakage after a period of 5 minutes. (These are the same

procedures to be used for performing the leak checks of the dump

valve and flush/fill line.)

(i) Repair the leak and retest. Or

(ii) Drain the affected lavatory system and placard the lavatory

inoperative until repairs can be accomplished. Or

(iii) Install an FAA-approved modification that deactivates the

vent system. After accomplishment of this deactivation, the leak

checks of the lavatory vent system may be discontinued. Or

(iv) Replace/modify the vent system in accordance with McDonnell

Douglas DC-9 Service Bulletin 38-41, Revision 3, dated July 5, 1994.

After accomplishment of this replacement/modification, the leak

checks of the lavatory vent system may be discontinued.

(2) Within 3 years after the effective date of this AD: Either

replace/modify the vent system in accordance with McDonnell Douglas

DC-9 Service Bulletin 38-41, Revision 3, dated July 5, 1994; or

install an FAA-approved modification that deactivates the vent

system. Accomplishment of either of these actions constitutes

terminating action for the leak checks of the lavatory vent system

that are required by this AD.

(f) For any affected airplane acquired after the effective date

of this AD: Before any operator places into service any airplane

subject to the requirements of this AD, a schedule for the

accomplishment of the leak checks required by this AD shall be

established in accordance with either paragraph (f)(1) or (f)(2) of

this AD, as applicable. After each leak check has been performed

once, each subsequent leak check must be performed in accordance

with the new operator's schedule, in accordance with either

paragraph (a) or (b) of this AD, as applicable.

(1) For airplanes previously maintained in accordance with this

AD: The first leak check to be performed by the new operator must be

accomplished in accordance with either the previous operator's

schedule or the new operator's schedule, whichever would result in

the earlier accomplishment date for that leak check.

(2) For airplanes that have not been previously maintained in

accordance with this AD: The first leak check to be performed by the

new operator must be accomplished prior to further flight; or in

accordance with a schedule approved by the FAA PMI, but within a

period not to exceed 200 flight hours.

(g) 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, Los Angeles ACO, FAA, Transport

Airplane Directorate. Operators shall submit their requests through

an appropriate FAA PMI, who may add comments and then send it to the

Manager, Los Angeles ACO.

Note 8: Information concerning the existence of approved

alternative methods of compliance with this AD, if any, may be

obtained from the Los Angeles ACO.

Note 9: For any valve that is not eligible for the extended leak

check intervals of this AD: To be eligible for the leak check

interval specified in paragraph (a)(1), (a)(2), (b)(2)(i), or

(b)(2)(ii), the service history data of the valve must be submitted

to the Manager, Los Angeles ACO, FAA, Transport Airplane

Directorate, with a request for approval of an alternative method of

compliance with this AD. The request should include an analysis of

known failure modes for the valve, if it is an existing design, and

known failure modes of similar valves. Additionally, the request

should include an explanation of how design features will preclude

these failure modes, results of qualification tests, and

approximately 25,000 flight hours or 25,000 flight cycles of service

history data, including a winter season, collected in accordance

with the requirements of paragraph (c) of this AD or a similar

program. The configuration of the entire drain system on the

airplanes used in evaluating a drain valve leak check interval

should be defined in the request so as to ensure that the drain

system is representative of the applications where the valve will be

used. As an example, data collected on a panel valve installed below

a ball valve would not be acceptable for substantiating a leak check

interval for the panel valve, since an installation below a ball

valve would not be representative of the normal applications where

it could be used.

(h) Special flight permits may be issued in accordance with

sections 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.

(i) The actions shall be done in accordance with McDonnell

Douglas DC-9 Service Bulletin 38-47, dated April 17, 1992; and

McDonnell Douglas DC-9 Service Bulletin 38-41, Revision 3, dated

July 5, 1994. This incorporation by reference was approved by the

Director of the Federal Register in accordance with 5 U.S.C. 552(a)

and 1 CFR part 51. Copies may be obtained from McDonnell Douglas

Corporation, 3855 Lakewood Boulevard, Long Beach, California 90846,

Attention: Technical Publications Business Administration,

Department C1-L51 (2-60). Copies may be inspected at the FAA,

Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton,

Washington; or at the FAA, Transport Airplane Directorate, Los

Angeles Aircraft Certification Office, 3960 Paramount Boulevard,

Lakewood, California; or at the Office of the Federal Register, 800

North Capitol Street, NW., suite 700, Washington, DC.

(j) This amendment becomes effective on December 11, 1996.

Issued in Renton, Washington, on October 18, 1996.

James V. Devany,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 96-27395 Filed 11-5-96; 8:45 am]

BILLING CODE 4910-13-U