[Federal Register Volume 61, Number 111 (Friday, June 7, 1996)]
[Rules and Regulations]
[Pages 29008-29015]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-14386]



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[[Page 29009]]


DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 95-NM-120-AD; Amendment 39-9661; AD 96-12-18]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas Model DC-10 Series 
Airplanes and Model MD-11F (Freighter) Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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

SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is applicable to all McDonnell Douglas Model DC-10 series airplanes and 
Model MD-11F airplanes. Among other things, this amendment 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; and requires 
the installation of a cap on the flush/fill line. 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.''

EFFECTIVE DATE: July 12, 1996.

ADDRESSES: Information related to this rulemaking action may be 
examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, 
SW., Renton, Washington; or at the FAA, Los Angeles Aircraft 
Certification Office, Transport Airplane Directorate, 3960 Paramount 
Boulevard, Lakewood, California.

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 Model DC-10 series airplanes 
and MD-11F airplanes was published in the Federal Register on November 
2, 1995 (60 FR 55668). That action proposed to require repetitive leak 
checks of the lavatory drain system and repair, if necessary; to 
provide for the option of revising the FAA-approved maintenance program 
to include a schedule of leak checks; and to require the installation 
of a cap on the flush/fill line.
    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

    One commenter supports the proposal.

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. Although the commenter 
states that, for all-cargo configurations of the affected airplanes, 
lavatory systems may be removed, the FAA is aware that most cases of 
all-cargo-configured Model DC-10's have at least one (forward) lavatory 
installed near the flightcrew deck. 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 To Revise Dump Valve Leak Check Procedure

    One commenter requests that the dump valve leak check procedures, 
specified throughout the proposal, be revised to permit the check to be 
performed using less fluid. The proposal states that the check is to be 
performed by filling the toilet tank with fluid to a level such that 
the bowl is approximately half full (at least 2 inches above the 
flapper in the bowl). However, this commenter states that the check can 
be accomplished and the same intent can be achieved with the use of 
less fluid. This commenter, a U.S. operator, indicates that use of less 
fluid would be more effective in terms of both time and cost. As an 
example, the commenter states that many Model DC-10 airplanes are 
equipped with aft waste tanks with a 90-gallon capacity; if the 
proposed check procedures are accomplished, over 120 gallons of fluid 
would be required to fill the toilet tanks to a level such that each of 
the four toilet bowls are half full. The commenter requests that this 
leak check on these airplanes be revised to require a maximum of only 
50 gallons of fluid to be used. The commenter asserts that this 
revision to the test procedures would still accomplish the same intent 
and would decrease the time required to test the system.
    The FAA does not concur. The procedure to fill the toilet bowl to 
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 To Delete the Method for Conducting Leak Checks

    One commenter requests that the proposal be revised to delete the 
defined method of conducting the leak check. The commenter suggests 
that, in lieu of requiring the aircraft to be pressurized, the proposal 
should merely stipulate that operators are to ``apply 3 psi [sic] 
across the valve'' and then allow operators to determine the most 
economical means of verifying the integrity of the seals. The commenter 
contends that requiring pressurization of the airplane causes 
unnecessary expenses to be incurred.
    The FAA does not consider that any revision to the final rule is 
necessary based on the commenter's request. The wording of the final 
rule (and proposal) simply states that the check must be performed with 
``a minimum of 3 PSID applied across the valve.'' To do this does not 
require that the airplane be pressurized. The FAA acknowledges that the 
NOTE contained in the proposal referred operators to the procedures 
specified in chapter 38-30-00 of the DC-10 Maintenance Manual procedure 
as one source of guidance for performing the check procedures, and 
those particular procedures do call for pressurizing the airplane. 
However, the reference to the Maintenance Manual procedure is merely 
informational; it is not a requirement and, likewise, pressurizing the 
airplane is not a requirement. The only requirement of the AD is that a 
minimum of 3 PSID be applied across the valve when the check is 
performed.

[[Page 29010]]

Request for Clarification of Check Requirements for Valves With Outer 
Seals and Inner Caps

    One commenter requests that proposed paragraphs (a)(3)(i) and 
(a)(3)(ii) be revised to define more clearly which types of valves 
require the outer seal to be pressure checked for leakage.
    The FAA agrees that some clarification is warranted. 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. For 
this type of valve, paragraph (a)(3)(ii) of the final rule provides an 
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 has included a new NOTE in paragraph (a)(3) to provide 
this information.

Request To Increase Leak Check Interval for Certain Shaw Aero 
Valves

    One commenter requests that proposed paragraph (a)(1) and (b)(2)(i) 
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;
     10101000BA2, having serial numbers 130 and higher; and
     10101000BB2, 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, amendment 39-9073 (59 FR 59124, November 16, 1994), which 
is applicable to Boeing Model 727 series airplanes; or a similar 
proposed rule applicable to Boeing Model 737 series airplanes 
(reference Docket No. 95-NM-111-AD; 60 FR 55673, November 2, 1995).
    The FAA concurs in part. The FAA finds that the 1,000-hour leak 
check interval is acceptable for most of the valves requested by the 
commenter. However, based on data received, only 10101000BB2 series 
valves having serial number 0011 and higher are acceptable for this 
leak check interval. The final rule has been revised accordingly.

Request for Increase in Leak Check Interval for All Shaw Aero 
Valves

    This same commenter requests that proposed paragraph (a)(1) and 
(b)(2)(i) be revised to permit the leak check interval of 1,000 hours 
for specified Shaw Aero valves to be increased to 2,000 hours upon the 
revision of an operator's maintenance procedures in accordance with the 
proposal and the submittal of data to substantiate the longer interval.
    The FAA does not consider that any change to the rule is necessary 
based on this commenter's request. Paragraph (c) of the final rule 
provides a procedure for collecting and submitting data to substantiate 
an increase in the leak check interval for any valve. The procedure 
specified in that paragraph is the appropriate one to follow for 
requesting any such increase in the leak check interval.

Request To Increase Leak Check Interval for Certain Kaiser Valves

    One commenter requests that proposed paragraphs (a)(1) and 
(b)(2)(i) be revised to increase the 1,000-hour leak check interval for 
Kaiser valves having part numbers 0218-0026 and 0218-0032. The 
commenter requests that the interval be increased to 2,500 hours based 
on qualification and test report data submitted.
    The FAA cannot concur with the commenter's request since 
insufficient data was submitted to support a longer inspection 
interval.

Request for Special Procedures for Systems With ``Interlock'' 
Mechanisms

    One commenter requests that proposed paragraph (b)(2)(ii) be 
revised to include different requirements for systems that incorporate 
an ``interlock'' mechanism that prevents the closure of the outer cap 
if the ``donut'' is not installed. This commenter states that if the 
functioning of the interlock mechanism is verified, the requirement for 
pressure leak checks should be similar to the checks of other valves 
that have both an inner and an outer seal.
    The FAA does not concur. Though the interlock mechanism ensures 
that the donut is installed, it does not ensure that the donut is in 
good condition. This type of valve, therefore, should be inspected at 
the same interval as other ``donut valves,'' unless data to 
substantiate a longer inspection interval can be provided. For this 
type of valve, the inner seal (the ``donut'') can be leak checked and 
the outer cap seal and seal surface can be inspected for wear in 
accordance with the procedures specified in paragraph (b)(2)(ii)(B) of 
the final rule.

Request To Allow Installation of an Alternative Lock Cap

    One commenter requests that proposed paragraph (d) be revised to 
allow the installation of a \1/4\-turn ball lock cap as an alternative 
to the proposed lever lock cap. This commenter, a non-U.S. operator, 
states that its fleet is already equipped with these lock caps and the 
commenter considers them equivalent to the caps that would be required 
by the AD.
    The FAA does not concur. Service experience has shown that, on many 
occasions, caps have been missing from the airplane. The lever lock cap 
installation required by this final rule secures the cap to the 
airplane better than other types of cap installations that the FAA 
currently knows of. However, under the provisions of paragraph (f) of 
this final rule, the FAA would consider approval of the use of other 
types of caps as an alternative method of compliance if sufficient data 
are presented to justify the use of a different type of cap.

Request To Address Need for Heaters on Flush/Fill Lines

    This same commenter indicates that the proposed installation of 
caps on the flush/fill lines, as would be required by paragraph (d) of 
the proposal, also may require the installation of heaters. Without 
such heaters, residual water will collect at the flush/fill nipples and 
freeze, thus hindering maintenance. This will increase the costs 
associated with the proposed rule.
    The FAA does not concur with the commenter's observation. 
Typically, caps already are installed on airplanes; this AD will 
require the installation of only a particular style of cap, and may not 
change the possible need for heaters on some airplanes. If the lines 
are allowed to drain thoroughly before the cap is closed, the need for 
heaters also would be minimized or eliminated.

Request for Permission To Use Alternative Check Valves on Flush/
Fill Line

    Several commenters request that proposed paragraph (d) be revised 
to permit the use of Monogram 4803-86 series check valves on flush/fill 
lines as an alternative to the proposed lever/lock caps. 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).
    The FAA concurs with the commenters' request. Paragraph (d) of the 
final rule has been revised to specify that installation of Monogram 
4803-86 series check valves on the flush/fill lines is an acceptable 
action for compliance.

[[Page 29011]]

    Additionally, paragraphs (a)(4) 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 for Revision of Cost Impact Information

    One commenter states that the cost impact information, as explained 
in the preamble to the proposal, indicated that required parts for 
installing a cap on the flush/fill line would cost $275 per airplane. 
The commenter states that the cost of parts is $275 per unit; based on 
an average of 8 units per airplane, the cost per airplane is $2,200.
    The FAA concurs. The cost information presented in the proposal 
inadvertently indicated the cost per unit, rather than the total cost 
per airplane. The commenter's figures are correct and the cost impact 
discussion, below, has been revised accordingly.

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 435 Model DC-10 series airplanes and Model 
MD-11F airplanes of the affected design in the worldwide fleet. The FAA 
estimates that 285 airplanes of U.S. registry, and 18 U.S. operators, 
will be affected by this proposed AD.
    For airplanes in the passenger configuration, the estimated costs 
associated with the requirements of this AD are as follows:
    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 two drains per 
airplane. Depending upon the type of valve installed and the flight 
utilization rate of the airplane, airplanes will be required to be 
inspected as few as 3 times per year or as many as 15 times per year. 
Based on these figures, the cost impact of the proposed leak check 
requirement on U.S. operators is expected to be between $1,440 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 2 work hours 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, 
airplanes will be required to be inspected as few as 3 times per year 
or as many as 15 times per year. Based on these figures, the cost 
impact of the inspection requirements on U.S. operators will be between 
$360 and $1,800 per airplane per year.
    3. Installation of cap on flush/fill line. This 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 
$2,200 per airplane. (There are 8 flush/fill lines per airplane, and 
parts for each line will cost approximately $275.) There currently are 
175 passenger-configured airplanes of U.S. registry that will be 
subject to this requirement. Based on these figures, the cost impact of 
the installation requirement on U.S. operators is expected to be 
$553,000, or $3,160 per airplane.
    For airplanes in the freighter configuration, the estimated costs 
associated with the requirements of this AD are as follows:
    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 is one drain per 
airplane. Depending upon the type of valve installed and the flight 
utilization rate of the airplane, airplanes will be required to be 
inspected as few as 3 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 of these airplanes is expected to be between $720 and 
$3,600 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, 
airplanes will be required to be inspected as few as 3 times per year 
or as many as 15 times per year. Based on these figures, the cost 
impact of the inspection requirements on U.S. operators of these 
airplanes will be between $180 and $900 per airplane per year.
    3. Installation of cap on flush/fill line. This 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 airplane. (There is 1 flush/fill line per airplane.) There 
currently are 110 freighter-configured airplanes of U.S. registry that 
will be subject to this requirement. Based on these figures, the cost 
impact of the installation requirement on U.S. operators of these 
airplanes is expected to be $43,450, or $395 per airplane.
    The number of required work hours, as indicated above, is presented 
as if the accomplishment of the actions required by this AD were to be 
conducted as ``stand 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 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 total cost impact of the maintenance 
revision requirement of this AD on the 18 affected U.S. operators is 
estimated to be $43,200, or $2,400 per operator.
    The cost impact figures discussed above are 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.
    The FAA recognizes that the obligation to maintain aircraft in an 
airworthy condition is vital, but sometimes expensive. Because AD's 
require specific actions to address specific unsafe conditions, they 
appear to impose costs that would not otherwise be borne by operators. 
However, because of the general obligation of operators to maintain 
aircraft in an airworthy condition, this appearance is deceptive. 
Attributing those costs solely to the issuance of this AD is 
unrealistic because, in the interest of maintaining safe aircraft, 
prudent operators would accomplish the required actions even if they 
were not required to do so by the AD.
    A full cost-benefit analysis has not been accomplished for this AD. 
As a matter of law, in order to be airworthy, an aircraft must conform 
to its type

[[Page 29012]]

design and be in a condition for safe operation. The type design is 
approved only after the FAA makes a determination that it complies with 
all applicable airworthiness requirements. In adopting and maintaining 
those requirements, the FAA has already made the determination that 
they establish a level of safety that is cost-beneficial. When the FAA, 
as in this AD, makes a finding of an unsafe condition, this means that 
the original cost-beneficial level of safety is no longer being 
achieved and that the required actions are necessary to restore that 
level of safety. Because this level of safety has already been 
determined to be cost-beneficial, a full cost-benefit analysis for this 
AD would be redundant and unnecessary.

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, 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:

96-12-18 McDonnell Douglas: Amendment 39-9661. Docket 95-NM-120-AD.

    Applicability: Model DC-10 series airplanes and Model MD-11F 
series airplanes; equipped with a lavatory drainage system, forward 
or aft; 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 (f) 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 previously 
accomplished.
    To prevent engine damage, airframe damage, and/or a 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 toilet dump valve leak checks required by this AD 
may be performed by filling the toilet tank with water/rinsing fluid 
to a level such that the bowl is approximately half full (at least 2 
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), and (a)(5) 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) 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)(1)(i) and (a)(1)(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.    
------------------------------------------------------------------------
Kaiser Electroprecision.........  0218-0032 series..  All serial        
                                                       numbers.         
Shaw Aero Devices...............  1010100C-N (or      All serial        
                                   higher dash         numbers.         
                                   number).                             
Shaw Aero Devices...............  1010100B-A-1......  0115 through 0121,
                                                       0146 through     
                                                       0164, 0180 and   
                                                       higher.          
Shaw Aero Devices -.............  10101000BA2-......  130 and higher.   
Shaw Aero Devices -.............  10101000BB2-......  0011 and higher.  
Shaw Aero Devices -.............  331 series -......  All serial        
                                                       numbers.         
Shaw Aero Devices -.............  332 series -......  All serial        
                                                       numbers.         
Pneudraulics -..................  9527 series-......  All serial        
                                                       numbers.         
------------------------------------------------------------------------

    (i) Conduct a leak check of the dump valve and 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. Any damaged parts must be 
replaced or repaired prior to further flight, or the affected 
lavatory(s) must be drained and placarded inoperative until repairs 
can be accomplished.
    (2) Within 600 flight hours after the effective date of this AD, 
and thereafter at intervals not to exceed 600 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 
2, below:

   Table 2.--Valves Requiring Leak Checks at 600-Flight Hour Intervals  
------------------------------------------------------------------------
          Manufacturer-                Part No.-          Serial No.    
------------------------------------------------------------------------
Kaiser Electroprecision -.......  0218-0026 series-.  All serial        
                                                       numbers.         

[[Page 29013]]

                                                                        
Shaw Aero Devices -.............  1010100C series,                      
                                   except as called                     
                                   out in Table 1,                      
                                   above,.                              
Shaw Aero Devices -.............  1010100B series,                      
                                   except as called                     
                                   out in Table 1,                      
                                   above.                               
------------------------------------------------------------------------



    (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 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. Any damaged parts must be 
replaced or repaired prior to further flight, or the affected 
lavatory(s) must be drained and placarded inoperative until repairs 
can be accomplished.
    (3) For each lavatory drain system not addressed in paragraph 
(a)(1) or (a)(2) 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 following procedures:
    (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 3 PSID applied across the valve. If the 
service panel drain valve has an inner door with a second positive 
seal, both the inner door 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. Any damaged parts must be 
replaced or repaired prior to further flight, or the affected 
lavatory(s) must be drained and placarded inoperative until repairs 
can be accomplished.

    Note 3: Some service panel valves have an inner seal that is 
closed when the outer cap is closed. For this type of valve, the 
fluid leakage from the outer cap can be checked only if the inner 
seal is removed; when the inner seal is in place, it prevents any 
fluid from reaching the outer cap seal. For this type of valve, the 
actions specified in paragraph (a)(3)(ii) are provided to allow 
inspection of the seal and seal surface of the outer cap seal as an 
alternative to leak checking the outer seal itself.

    (4) 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 either of the procedures specified in 
paragraphs (a)(4)(i) or (a)(4)(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)(4)(i)(A) or (a)(4)(i)(B) of this AD:
    (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.

    Note 4: The Inspection/Check procedure specified in DC-10 
Maintenance Manual, chapter 38-30-00, pages 601 and 602, dated June 
1, 1993, may be referred to as guidance for the procedures required 
by this paragraph.

    (ii) For airplanes equipped with a check valve vacuum breaker, 
Monogram part number series 4803-86: 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.
    (5) If a leak is discovered during any leak check required by 
paragraph (a) of this AD, prior to further flight, accomplish either 
of the procedures specified in paragraph (a)(5)(i) or (a)(5)(ii) of 
this AD:
    (i) Repair the leak and retest. Or
    (ii) 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), and 
(b)(6) of this AD.
    (1) For each lavatory drain system: 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, replace the valve seals. Any revision to this replacement 
schedule must be approved by the Manager, Los Angeles Aircraft 
Certification Office (ACO), FAA, Transport Airplane Directorate.
    (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), and (b)(2)(iii) 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/tested at that time at each service 
panel location. Any revision to the leak check schedule must be 
approved by the Manager, Los Angeles ACO, FAA, Transport Airplane 
Directorate.
    (i) 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 
applicable procedures specified in paragraphs (b)(2)(i)(A) and 
(b)(2)(i)(B) of this AD for each lavatory drain system with a 
service panel drain valve installed that is listed in Table 3, 
below:

  Table 3.--Valves Requiring Leak Checks at 1,000-Flight Hour Intervals 
------------------------------------------------------------------------
          Manufacturer                 Part No.           Serial No.    
------------------------------------------------------------------------
Kaiser Electroprecision.........  0218-0032 series..  All serial        
                                                       numbers.         
Kaiser Electroprecision.........  0218-0026 series..  All serial        
                                                       numbers.         
Shaw Aero Devices...............  1010100C series...  All serial        
                                                       numbers.         
Shaw Aero Devices...............  1010100B series...  All series        
                                                       numbers.         
Shaw Aero Devices...............  10101000BA2.......  130 and higher.   
Shaw Aero Devices...............  10101000BB2.......  0011 and higher.  
Shaw Aero Devices...............  331 series........  All serial        
                                                       numbers.         
Shaw Aero Devices...............  332 series........  All serial        
                                                       numbers.         
Pneudraulics....................  9527 series.......  All serial        
                                                       numbers.         
------------------------------------------------------------------------

    (A) Conduct leak checks of the dump valve and service panel 
drain valve. The service panel drain leak 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. And
    (B) Visually inspect the service panel drain valve outer cap/
door 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 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, accomplish the 
applicable procedures in

[[Page 29014]]

paragraph (b)(2)(ii)(A) and (b)(2)(ii)(B) of this AD for each 
lavatory drain system with a lavatory drain system valve that 
incorporates one of the valves listed in Table 4, below:

   Table 4.--Valves Requiring Leak Checks at 200-Flight Hour Intervals  
------------------------------------------------------------------------
          Manufacturer                 Part No.           Serial No.    
------------------------------------------------------------------------
Kaiser Electroprecision -.......  4259-20 or 4259-31  All serial        
                                   ``donut''           numbers.         
                                   assemblies -(or                      
                                   substitute                           
                                   assemblies from                      
                                   another                              
                                   manufacturer).                       
Kaiser Roylyn...................  2651-231..........                    
Kaiser Roylyn...................  2651-259..........                    
------------------------------------------------------------------------

    (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. Both the 
donut and the outer cap/door must be leak checked.
    (B) For service panel valves that have an inner seal: In lieu of 
pressure testing, visually inspect the outer cap seal and seal 
surface for damage or wear. Any damaged parts must be replaced or 
repaired prior to further flight, or the affected lavatory(s) must 
be drained and placarded inoperative until repairs can be 
accomplished.
    (iii) For each lavatory drain system that incorporates any other 
type of approved valves: 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 
both of the following procedures:
    (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. And
    (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. 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.
    (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 procedure specified in either 
paragraph (b)(3)(i) or (b)(3)(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 (b)(3)(i)(A) or (b)(3)(i)(B) of this AD:
    (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.

    Note 5: The Inspection/Check procedure specified in DC-10 
Maintenance Manual, chapter 38-30-00, pages 601 and 602, dated June 
1, 1993, may be referred to as guidance for the procedures required 
by this paragraph.

    (ii) For airplanes equipped with a check valve vacuum breaker, 
Monogram part number series 4803-86: 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, 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.
    (6) Provide training programs for maintenance and servicing 
personnel that include information on ``Blue Ice Awareness'' and the 
hazards of ``blue ice.''
    (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.);
    (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 prior to a leak check will 
not cause that leak check to be recorded as a failure.]

    Note 6: Requests for approval of revised leak check intervals 
may be submitted in any format, provided that the data give the same 
level of assurance specified in paragraph (c) of this AD.
    Note 7: 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.

    (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 for all 
lavatory service panels. The cap must be either an FAA-approved 
lever/lock cap; or a lever/lock cap installed in accordance with 
McDonnell Douglas Service Bulletin 38-65 (for Model DC-10 series 
airplanes) or Service Bulletin 38-39 [for Model MD-11F series 
airplanes (freighter)], as applicable. Or
    (2) Install a Monogram 4803-86 series check valve on the flush/
fill lines for all lavatory service panels.
    (e) 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 (e)(1) or (e)(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 the previous operator's schedule or 
with 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.
    (f) 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

[[Page 29015]]

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 paragraphs (a)(1) and (b)(2)(i), the service 
history data of the valve must be submitted to the Manager, Los 
Angeles ACO, FAA, Transport Airplane Directorate, with a request for 
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.

    (g) 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.
    (h) This amendment becomes effective on July 12, 1996.

    Issued in Renton, Washington, on June 3, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-14386 Filed 6-6-96; 8:45 am]
BILLING CODE 4910-13-U