AD 93-17-02
final rule
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | The Boeing Company | 737-200 Series | Airworthiness Directives; BOEING Model 737-300, -400, and -500 Series Airplanes |
| aircraft | The Boeing Company | 737-300 Series | Airworthiness Directives; BOEING Model 737-300, -400, and -500 Series Airplanes |
| aircraft | The Boeing Company | 737-400 Series | Airworthiness Directives; BOEING Model 737-300, -400, and -500 Series Airplanes |
| aircraft | The Boeing Company | 737-500 Series | Airworthiness Directives; BOEING Model 737-300, -400, and -500 Series Airplanes |
Unsafe Condition
Failure of the wing main tank float switch electrical conduits and subsequent fuel leakage resulting in an engine tail pipe fire.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect wing main tank float switch electrical conduits for fuel leakage and condensation build-up at intervals not to exceed 1,500 flight hours. If leakage or condensation is found, purge and install a new vapor seal assembly before further flight. Within 3 years after the effective date, install grease in the conduits to terminate inspection requirements.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within 90 days after the effective date of the referenced ADs and thereafter at intervals not to exceed 1,500 flight hours. For grease installation, within 3 years after November 24, 1993.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Boeing Model 737-300, -400, and -500 series airplanes through line position 2428; Model 737-200 series equipped with DC powered fuel tank float switches.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Wing Main Tank Float Switch
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_93-17-02.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 93-17-02 Document Type: AD Final Rules Docket Number: 93-NM-05-AD Subject Heading: Airworthiness Directives; BOEING Model 737-300, -400, and -500 Series Airplanes Subject: Wing Main Tank Float Switch Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 11/24/1993 Make: The Boeing Company Model: 737-200 Series | 737-300 Series | 737-400 Series | 737-500 Series Product Type: Aircraft Product Subtype: Large Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: Updated RGL applicability to match AD applicability; CAR C-11-185 AIRWORTHINESS DIRECTIVES FINAL RULES: 93-17-02 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: 93-NM-05-AD AMENDMENT: 39-8672 AD NUMBER: 93-17-02 SUBJECT HEADING: Airworthiness Directives; BOEING Model 737-300, -400, and -500 Series Airplanes ACTION: SUMMARY: DATES: Effective November 24, 1993. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 93-17-02 BOEING: Amendment 39-8672. Docket 93-NM-05-AD. Supersedes AD 91-20-11, Amendment 39-8045. Applicability: Model 737-300, -400, and -500 series airplanes, line positions through 2428, inclusive; and Model 737-200 series airplanes, equipped with DC powered fuel tank float switches; certificated in any category. Compliance: Required as indicated, unless accomplished previously. To prevent failure of the wing main tank float switch electrical conduits and subsequent fuel leakage resulting in an engine tail pipe fire, accomplish the following: (a) For airplanes listed in Boeing Service Letter 737-SL-28-36, dated November 30, 1990: Within 90 days after November 7, 1991 (the effective date of AD 91-20-11, Amendment 39-8045), and thereafter at intervals not to exceed 1,500 flight hours, perform an inspection of the wing main tank float switch electrical conduits for fuel leakage and condensation build-up, in accordance with Boeing Service Letter 737-SL-28-36, dated November 30, 1990. If evidence of fuel leakage and/or water condensation is found while performing the initial or repetitive inspections, prior to further flight, purge and install a new vapor seal assembly in accordance with the Boeing service letter. NOTE 1: The installation of a new vapor seal assembly does not terminate the requirement for the 1,500 flight hour repetitive inspection. (b) For airplanes listed in Boeing Service Letter 737-SL-28-42, dated December 15, 1992, that are not subject to paragraph (a) of this AD: Within 90 days after the effective date of this AD, and thereafter at intervals not to exceed 1,500 flight hours, perform an inspection of the wing main tank float switch electrical conduits for fuel leakage and condensation build-up, in accordance with Boeing Service Letter 737-SL-28-36, dated November 30, 1990. If evidence of fuel leakage and/or water condensation is found while performing the initial or repetitive inspections, prior to further flight, purge and install a new vapor seal assembly in accordance with the Boeing service letter. NOTE 2: The installation of a new vapor seal assembly does not terminate the requirement for the 1,500 flight hour repetitive inspection. (c) Within 3 years after the effective date of this AD, install grease in the interior of the wing main tank float switch electrical conduits in accordance with Boeing Service Letter 737-SL-28-42, dated December 15, 1992, or 737-SL-28-42-A, dated July 15, 1993. Installation of grease in the conduits constitutes terminating action for the inspections required by paragraphs (a) and (b) of this AD. (d) 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 Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Seattle ACO. NOTE 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO. (e) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished. (f) The inspections shall be done in accordance with Boeing Service Letter 737-SL-28-36, dated November 30, 1990. The installation shall be done in accordance with Boeing Service Letter 737-SL-28-42, dated December 15, 1992, or Boeing Service Letter 737-SL-28-42-A, dated July 15, 1993. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. (g) This amendment becomes effective on November 24, 1993. FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_93-17-02.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 93-17-02 Document Type: AD Final Rules Docket Number: 93-NM-05-AD Subject Heading: Airworthiness Directives; BOEING Model 737-300, -400, and -500 Series Airplanes Subject: Wing Main Tank Float Switch Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 11/24/1993 Make: The Boeing Company Model: 737-200 Series | 737-300 Series | 737-400 Series | 737-500 Series Product Type: Aircraft Product Subtype: Large Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: Updated RGL applicability to match AD applicability; CAR C-11-185 AIRWORTHINESS DIRECTIVES FINAL RULES: 93-17-02 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: 93-NM-05-AD AMENDMENT: 39-8672 AD NUMBER: 93-17-02 SUBJECT HEADING: Airworthiness Directives; BOEING Model 737-300, -400, and -500 Series Airplanes ACTION: SUMMARY: DATES: Effective November 24, 1993. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 93-17-02 BOEING: Amendment 39-8672. Docket 93-NM-05-AD. Supersedes AD 91-20-11, Amendment 39-8045. Applicability: Model 737-300, -400, and -500 series airplanes, line positions through 2428, inclusive; and Model 737-200 series airplanes, equipped with DC powered fuel tank float switches; certificated in any category. Compliance: Required as indicated, unless accomplished previously. To prevent failure of the wing main tank float switch electrical conduits and subsequent fuel leakage resulting in an engine tail pipe fire, accomplish the following: (a) For airplanes listed in Boeing Service Letter 737-SL-28-36, dated November 30, 1990: Within 90 days after November 7, 1991 (the effective date of AD 91-20-11, Amendment 39-8045), and thereafter at intervals not to exceed 1,500 flight hours, perform an inspection of the wing main tank float switch electrical conduits for fuel leakage and condensation build-up, in accordance with Boeing Service Letter 737-SL-28-36, dated November 30, 1990. If evidence of fuel leakage and/or water condensation is found while performing the initial or repetitive inspections, prior to further flight, purge and install a new vapor seal assembly in accordance with the Boeing service letter. NOTE 1: The installation of a new vapor seal assembly does not terminate the requirement for the 1,500 flight hour repetitive inspection. (b) For airplanes listed in Boeing Service Letter 737-SL-28-42, dated December 15, 1992, that are not subject to paragraph (a) of this AD: Within 90 days after the effective date of this AD, and thereafter at intervals not to exceed 1,500 flight hours, perform an inspection of the wing main tank float switch electrical conduits for fuel leakage and condensation build-up, in accordance with Boeing Service Letter 737-SL-28-36, dated November 30, 1990. If evidence of fuel leakage and/or water condensation is found while performing the initial or repetitive inspections, prior to further flight, purge and install a new vapor seal assembly in accordance with the Boeing service letter. NOTE 2: The installation of a new vapor seal assembly does not terminate the requirement for the 1,500 flight hour repetitive inspection. (c) Within 3 years after the effective date of this AD, install grease in the interior of the wing main tank float switch electrical conduits in accordance with Boeing Service Letter 737-SL-28-42, dated December 15, 1992, or 737-SL-28-42-A, dated July 15, 1993. Installation of grease in the conduits constitutes terminating action for the inspections required by paragraphs (a) and (b) of this AD. (d) 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 Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Seattle ACO. NOTE 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO. (e) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished. (f) The inspections shall be done in accordance with Boeing Service Letter 737-SL-28-36, dated November 30, 1990. The installation shall be done in accordance with Boeing Service Letter 737-SL-28-42, dated December 15, 1992, or Boeing Service Letter 737-SL-28-42-A, dated July 15, 1993. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. (g) This amendment becomes effective on November 24, 1993. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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