AD 60-04-01
final rule
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Bendix | Public Address Speaker Systems | Airworthiness Directives; Bendix: Applies to All Aircraft Public Address Speaker Systems Using the Bendix MI-51B Amspeaker, Which Have Carbon Resistors in Parallel With or in Lieu of Wire Wound Resistors R-103 and R-106 |
| appliance | Bendix | Public Address Speaker Systems | Airworthiness Directives; Bendix: Applies to All Aircraft Public Address Speaker Systems Using the Bendix MI-51B Amspeaker, Which Have Carbon Resistors in Parallel With or in Lieu of Wire Wound Resistors R-103 and R-106 |
Unsafe Condition
Overheating of carbon resistors R-103 and R-106 in the Bendix MI-51B Amspeaker can destroy the speaker cone and create a fire hazard.
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Required Actions
Remove carbon resistors paralleled with or substituted for R-103 and R-106 by either clipping them out or replacing the parallel networks with 0.75 ohm wire wound resistors (±5%, 1/2 W).
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Compliance Time
June 1, 1960
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Affected Aircraft
Bendix Public Address Speaker Systems with MI-51B Amspeaker, serial numbers 1001 to 1201 (serial numbers 1001 to 1051 may have been modified in service)
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Federal Register Abstract
Public Address Speaker Systems
Applicability Source Text
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AD Final Rules - DRS_60-04-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 60-04-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Bendix: Applies to All Aircraft Public Address Speaker Systems Using the Bendix MI-51B Amspeaker, Which Have Carbon Resi... ...Show more Subject: Public Address Speaker Systems Status: Current Citation: Federal Register: February 20, 1960 Citation Publish Date: 02/20/1960 Effective Date: Make: Bendix Model: Public Address Speaker Systems Product Type: Appliance Product Subtype: Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 60-04-01 CITATION: [Federal Register: February 20, 1960] PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 60-04-01 SUBJECT HEADING: Airworthiness Directives; Bendix: Applies to All Aircraft Public Address Speaker Systems Using the Bendix MI-51B Amspeaker, Which Have Carbon Resistors in Parallel With or in Lieu of Wire Wound Resistors R-103 and R-106 ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 60-04-01 BENDIX: Amendment 107 Part 507 Federal Register February 20, 1960. Applies to All Aircraft Public Address Speaker Systems Using the Bendix MI-51B Amspeaker, Serial Numbers 1001 To 1201, Which Have Carbon Resistors in Parallel With or in Lieu of Wire Wound Resistors R-103 and R-106. (Serial Numbers 1001 To 1051 May Have Been So Modified In Service.) Compliance required by June 1, 1960. Failures have occurred where the speaker cone of the MI-51B was destroyed by fire as a result of overheating of these carbon resistors, thus creating a possible hazardous condition. Due to the seriousness of the fire hazard associated with these failures, any carbon resistors paralleled with or substituted for resistors R-103 and R-106 shall be removed in accordance with either of the following methods: (a) Method No. 1. Clip out 3.9 ohm carbon resistors connected across wire wound resistors R-103 and R-106. (Removal of these resistors will reduce the audio output by approximately 10 percent.) (b) Method No. 2. Replace each of the parallel networks composed of 3.9 ohm carbon resistors in parallel with wire wound resistor R-103 and R-106, with a 0.75 ohm wire wound resistor (plus-minus 5 percent, 1/2 W). (Bendix Service Bulletin No. M-273 dated July 8, 1959 covers the same subject.) FOOTER:
Document Text
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AD Final Rules - DRS_60-04-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 60-04-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Bendix: Applies to All Aircraft Public Address Speaker Systems Using the Bendix MI-51B Amspeaker, Which Have Carbon Resi... ...Show more Subject: Public Address Speaker Systems Status: Current Citation: Federal Register: February 20, 1960 Citation Publish Date: 02/20/1960 Effective Date: Make: Bendix Model: Public Address Speaker Systems Product Type: Appliance Product Subtype: Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 60-04-01 CITATION: [Federal Register: February 20, 1960] PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 60-04-01 SUBJECT HEADING: Airworthiness Directives; Bendix: Applies to All Aircraft Public Address Speaker Systems Using the Bendix MI-51B Amspeaker, Which Have Carbon Resistors in Parallel With or in Lieu of Wire Wound Resistors R-103 and R-106 ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 60-04-01 BENDIX: Amendment 107 Part 507 Federal Register February 20, 1960. Applies to All Aircraft Public Address Speaker Systems Using the Bendix MI-51B Amspeaker, Serial Numbers 1001 To 1201, Which Have Carbon Resistors in Parallel With or in Lieu of Wire Wound Resistors R-103 and R-106. (Serial Numbers 1001 To 1051 May Have Been So Modified In Service.) Compliance required by June 1, 1960. Failures have occurred where the speaker cone of the MI-51B was destroyed by fire as a result of overheating of these carbon resistors, thus creating a possible hazardous condition. Due to the seriousness of the fire hazard associated with these failures, any carbon resistors paralleled with or substituted for resistors R-103 and R-106 shall be removed in accordance with either of the following methods: (a) Method No. 1. Clip out 3.9 ohm carbon resistors connected across wire wound resistors R-103 and R-106. (Removal of these resistors will reduce the audio output by approximately 10 percent.) (b) Method No. 2. Replace each of the parallel networks composed of 3.9 ohm carbon resistors in parallel with wire wound resistor R-103 and R-106, with a 0.75 ohm wire wound resistor (plus-minus 5 percent, 1/2 W). (Bendix Service Bulletin No. M-273 dated July 8, 1959 covers the same subject.) FOOTER:
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