[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.
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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
