Lavatory Dump Valve

Category - Airframe
Effective Date - 12/16/1994
Recurring - Yes
Supersedes - 86-05-07
Superseded by - N/A
Amendment 39-9073, Docket No. 90-NM-265-AD.
Supersedes AD 86-05-07, Amendment 39-5250.

Applicability:
All Model 727 series airplanes, certificated in any category.

Compliance:
Required as indicated, unless previously accomplished. To prevent engine damage or separation, airframe damage, and/or hazard to persons or property on the ground as a result of "blue ice" that has formed from leakage of the lavatory drain system and dislodged from the airplane, accomplish the following:

NOTE 1: The 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), (a)(5) and (a)(6) of this AD. If the waste drain system incorporates more than one type of valve, only one of the waste drain system leak check procedures (the one that applies to the equipment with the longest leak check interval) must be conducted at each service panel location. (1) For each lavatory drain system that has an in-line drain valve installed, Kaiser Electroprecision part number series 2651-329, 2651-334, or 2651-278:
Within 1,500 flight hours after the effective date of this AD, and thereafter at intervals not to exceed 1,500 flight hours, accomplish the following:
(i) Conduct a leak check of the dump valve (in-tank valve that is spring loaded closed and operable by a T-handle at the service panel) and the in-line drain valve. The in-line drain valve leak check must be performed with a minimum of 3 pounds per square inch differential pressure (PSID) applied across the valve.
(ii) Visually inspect the service panel drain valve outer cap seal and the inner seal (if the valve has an inner door/closure device with a second positive seal), and the seal mating surfaces, for wear or damage that may allow leakage. Prior to further flight, replace any worn or damaged seal, and repairor replace any damaged seal mating surfaces, in accordance with the valve manufacturer'smaintenance manual.
(2) For each lavatory drain system that has a service panel drain valve installed, Kaiser Electroprecision part number series 0218-0032; or Shaw Aero Devices part number 1010100C-N (or higher dash number); or Shaw Aero Devices part number 1010100B-A-1, serial numbers 0115 through 0121, 0146 through 0164, and -0180 and higher; or Pneudraulics part number series 9527: Within 1,000 flight hours after the effective date of this AD, and thereafter at intervals not to exceed 1,000 flight hours, 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.
(3) For each lavatory drain system that has a service panel drain valve installed, Kaiser Electroprecision part number series 0218-0026, or Shaw Aero Devices part number series 1010100C (except as called out in paragraph (a)(2) above), or Shaw Aero Devices part number 1010100B (except as called out in paragraph (a)(2) above):
Within 600 flight hours after the effective date of this AD, and thereafter at intervals not to exceed 600 flight hours, 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.
(4) For each lavatory drain system not addressed in paragraph (a)(1), (a)(2), or (a)(3) of this AD: Within 200 flight hours after the effective date of this AD, and thereafter at intervals not to exceed 200 flight hours, 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.
(5) For flush/fill lines: Within 5,000 flight hours after the effective date of this AD, and thereafter at intervals not to exceed 5,000 flight hours, accomplish either of the following procedures specified in paragraphs (a)(5)(i) or (a)(5)(ii) of this AD:
(i) 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
(ii) 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 2: The leak test procedure specified in Boeing Service Letter 737-SL-38-3-A, dated March 19, 1990, may be referred to as guidance for the procedures required by this paragraph.
(6) If a leak is discovered during any leak check required by paragraph (a) of this AD, prior to further flight, accomplish one of the following procedures:
(i) Repair the leak; 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) Replace the valve seals in accordance with the applicable schedule specified in paragraphs (b)(1)(i) and (b)(1)(ii) of this AD. Any revision to this replacement schedule must be approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate.
(i) For each lavatory drain system that has an in-line drain valve installed, Kaiser Electroprecision part number series 2651-329, 2651-334, or 2651-278: Replace the seals within 5,000 flight hours after revision of the maintenance program in accordance with paragraph (b) of this AD, and thereafter at intervals not to exceed 52 months.
(ii) For each lavatory drain system that has any other type of drain valve: Replace the seals within 5,000 flight hours after revision of the maintenance program in accordance with paragraph (b) of this AD, and thereafter at intervals not to exceed 18 months.
(2) Conduct periodic leak checks of the lavatory drain systems in accordance with the applicable schedule specified in paragraphs (b)(2)(i), (b)(2)(ii), (b)(2)(iii), and (b)(2)(iv) of this AD.
If the waste drain system incorporates more than one type of valve, only one of the waste drain system leak check procedures (the one that applies to the equipment with the longest leak check interval) must be conducted at each service panel location. Any revision to the leak check schedule must be approved by the Manager, Seattle ACO, FAA, Transport Airplane Directorate.
(i) For each lavatory drain system that has an in-line drain valve, Kaiser Electroprecision part number series 2651-278, 2651-329, or 2651-334: Within 5,000 flight hours after revision of the maintenance program in accordance with paragraph (b) of this AD, and thereafter at intervals not to exceed 24 months or 5,000 flight hours, whichever occurs later, accomplish the proceduresspecified in paragraphs (b)(2)(i)(A) and (b)(2)(i)(B) of this AD:
(A) Conduct a leak check of the dump valve (in-tank valve that is spring loaded closed and operable by a T-handle at the service panel), and in-line drain valve. The in-line drain valve leak check must be performed with a minimum of 3 pounds per square inch differential pressure (PSID) applied across the valve.
(B) Visually inspect the service panel drain valve outer cap/door seal and the inner seal (if the valve has an inner door/closure device with a second positive seal) and seal mating surface for wear or damage that may cause leakage. Any worn or damaged seal must be replaced and any damaged seal mating surface must be repaired or replaced, prior to further flight, in accordance with the valve manufacturer's maintenance manual.
(ii) For each lavatory drain system that has a service panel drain valve installed, Kaiser Electroprecision part number series 0218-0032, or Kaiser Electroprecision part number series 0218-0026, or Shaw Aero Devices part number series 1010100C, or Shaw Aero Devises part number series 1010100B, or Pneudraulics part number series 9527: Within 1,000 flight hours after revising the maintenance program in accordance with paragraph (b) of this AD, and thereafter at intervals not to exceed 1,000 flight hours, accomplish the procedures specified in paragraphs (b)(2)(ii)(A) and (b)(2)(ii)(B) of this AD:
(A) Conduct leak checks of the dump valve and service panel drain valve. The service panel drain valve leak check must be performed with a minimum of 3 PSID applied across the valve. Only the inner door/closure device of the service panel drain valve must be leak checked.
(B) Visually inspect the service panel drain valve outer cap/door seal and seal mating surface for wear or damage that may cause leakage. Any worn or damaged seal must be replaced, and any damaged seal mating surface must be repaired or replaced, prior to further flight, in accordancewith the valve manufacturer's maintenance manual.
(iii) For each lavatory drain system with a lavatory drain system valve that either incorporates "donut" assemblies (or substitute assemblies from another manufacturer) Kaiser Electroprecision part number 4259-20 or 4259-31, or incorporates Kaiser Roylyn part number 2651-194C, 2651-197C, 2651-216, 2651-219, 2651-235, 2651-256, 2651-258, 2651-259, 2651-260, 2651-275, 2651-282, or 2651-286:
Within 200 flight hours after revising the maintenance program in accordance with paragraph (b) of this AD, and thereafter at intervals not to exceed 200 flight hours, conduct leak checks of the dump valve and the service panel drain valve. The service panel drain valve leak check must be performed with a minimum 3 PSID applied across the valve. Both the donut and the outer cap/door must be leak checked.
(iv) For each lavatory drain system that incorporates any other type of approved valves: Within 400flight hours after revising the maintenance program in accordance with paragraph (b) of this AD, and thereafter at intervals not to exceed 400 flight hours accomplish the procedures specified in paragraphs (b)(2)(iv)(A) and (b)(2)(iv)(B) of this AD:
(A) Conduct leak checks of the dump valve and the service panel drain valve. The service panel drain valve leak check must be performed with a minimum 3 PSID applied across the valve. If the service panel drain valve has an inner door/closure device with a second positive seal, only the inner door must be leak checked.
(B) If the valve has an inner door/closure device with a second positive seal: Visually inspect the service panel drain valve outer door/cap seal and seal mating surface for wear or damage that may cause leakage. 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 either of the procedures specified in paragraphs (b)(3)(i) or (b)(3)(ii) of this AD:
(i) 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 (ii) 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 3: The leak test procedure specified in Boeing Service Letter 737-SL-38-3-A, dated March 19, 1990, may be referred to as guidance for the procedures required by this paragraph.

(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, which ever occurs later.
(5) Provide procedures for reporting leakage. These procedures shall provide that any "horizontal blue streak" findings must be reported to maintenance and that, prior to further flight, the leaking system shall either be repaired, or be drained and placarded inoperative.
(i) For systems incorporating an in-line drain valve, Kaiser Electroprecision part number series 2651-278, 2651-329, or 2651-334: The reporting procedures must include provisions for reporting to maintenance any instances of abnormal operation of the valve handle for the in-line drain valve, as observed by service personnel during normal servicing.
(A) Additionally, these provisions must include procedures for either: prior to further flight, following the in-line drain valve manufacturer's recommended troubleshooting procedures and correction of the discrepancy; or prior to further flight, draining the lavatory system and placarding it inoperative until the correction of the discrepancy can be accomplished.
(B) If the drain system also includes an additional service panel drain valve, Kaiser Electroprecision part number series 0218-0026 or 0218-0032, or Shaw Aero Devices part number series 1010100C or 1010100B, or Pneudraulics part number series 9527, indications of abnormal operation of the valve handle for the in-line drain valve need not be addressed immediately if a leak check of the service panel drain valve indicates no leakage or other discrepancy. In these cases, repair of the in-line drain valve must be accomplished within 1,000 flight hours after the leak check of the additional service panel drain valve.
(6) Provide training programs for maintenance and servicing personnel that include information on "Blue Ice Awareness" and the hazards of "blue ice."
(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, Seattle ACO, FAA, Transport Airplane Directorate. Requests for such revisions must be submitted to the Manager of the Seattle 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 4: 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 5: 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, install a lever/lock cap on the flush/fill lines for forward, aft, and executive lavatories. The cap must be either an FAA-approved lever/lock cap, or a cap installed in accordance with Boeing Service Bulletin 727-38-0021, dated July 30, 1992.
(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, Seattle 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, Seattle ACO.

NOTE 6: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO.

NOTE 7: 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), (a)(2), (b)(2)(i), and (b)(2)(ii), the service history data of the valve must be submitted to the Manager, Seattle 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. One of the factors that the FAA will consider in approving alternative valve designs is whether the valve meets Boeing Specification S417T105 or 10-62213; however, meeting the Boeing specification is not a prerequisite for approval of alternative valve designs.
(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 December 16, 1994.

FOR FURTHER INFORMATION CONTACT:
Don Eiford, Aerospace Engineer, Seattle Aircraft Certification Office, Systems and Equipment Branch, ANM-130S, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206) 227-2788; fax (206) 227-1811.