AD 84-21-01 R1
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | BRITISH | 125 | Airworthiness Directives; BRITISH AEROSPACE Model DH/HS/BH 125 Series Airplanes |
Unsafe Condition
Electrical failures in the 'ZL' panel due to insufficient 80 amp fuses.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Replace the two existing 80 amp fuses on the 'ZL' panel with 100 amp fuses. Install covers on the 'ZL' panel following specified service bulletins based on aircraft STC or engine type. Alternate means of compliance may be approved.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
within the next 90 days after the effective date of this AD unless previously accomplished
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Affected Aircraft
BRITISH AEROSPACE Model DH/HS/BH 125 series airplanes with serial numbers specified in service bulletins 24-239-(2885), 6-7, and 24-220-(2749)
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Replacement Fuses - ZL Panel
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_84-21-01_R.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 84-21-01 R1 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; BRITISH AEROSPACE Model DH/HS/BH 125 Series Airplanes Subject: Replacement Fuses - ZL Panel Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 02/11/1985 Make: Model: BH.125 Series 400A | BH.125 Series 600A | DH.125 Series 1A | DH.125 Series 1A/R-522 | DH.125 Series ...Show more Product Type: Aircraft Product Subtype: Large Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 84-21-01 R1 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-4993 AD NUMBER: 84-21-01 R1 SUBJECT HEADING: Airworthiness Directives; BRITISH AEROSPACE Model DH/HS/BH 125 Series Airplanes ACTION: SUMMARY: DATES: Effective February 11, 1985. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 84-21-01 R1 BRITISH AEROSPACE: Amendment 39-4932 as amended by Amendment 39- 4993. Applies to all Model DH/HS/BH 125 series airplanes certificated in all categories, with the serial numbers specified in the service bulletins listed below. Compliance is required as indicated. To prevent electrical failures in the 'ZL' panel, accomplish the following within the next 90 days after the effective date of this AD unless previously accomplished: A. Replace the two existing 80 amp fuses on the 'ZL' panel with 100 amp fuses, in accordance with the Accomplishment Instructions of British Aerospace 125 Aircraft Service Bulletin 24-239-(2885), Revision 1, dated February 27, 1984. B. Install covers on the 'ZL' panel as follows: 1. For aircraft that have accomplished STC SA3870WE or STC SA3925WE, in accordance with the Accomplishment Instructions of AiResearch Aviation Company Service Bulletin No. 6-7, dated October 25, 1983. 2. For any other aircraft fitted with Garrett TFE 731-3 engines, in accordance with the Accomplishment Instructions of British Aerospace 125 Aircraft Service Bulletin 24-220-(2749), Revision 3, dated March 3, 1983. C. Alternate means of compliance which provide an equivalent level of safety may be used when approved by the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region. D. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base for the accomplishment of inspections and/or modifications required by this AD. Amendment 39-4932 became effective November 14, 1984. This Amendment 39-4993 becomes effective February 11, 1985. FOOTER:
Document Text
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AD Final Rules - DRS_84-21-01_R.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 84-21-01 R1 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; BRITISH AEROSPACE Model DH/HS/BH 125 Series Airplanes Subject: Replacement Fuses - ZL Panel Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 02/11/1985 Make: Model: BH.125 Series 400A | BH.125 Series 600A | DH.125 Series 1A | DH.125 Series 1A/R-522 | DH.125 Series ...Show more 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: AIRWORTHINESS DIRECTIVES FINAL RULES: 84-21-01 R1 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-4993 AD NUMBER: 84-21-01 R1 SUBJECT HEADING: Airworthiness Directives; BRITISH AEROSPACE Model DH/HS/BH 125 Series Airplanes ACTION: SUMMARY: DATES: Effective February 11, 1985. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 84-21-01 R1 BRITISH AEROSPACE: Amendment 39-4932 as amended by Amendment 39- 4993. Applies to all Model DH/HS/BH 125 series airplanes certificated in all categories, with the serial numbers specified in the service bulletins listed below. Compliance is required as indicated. To prevent electrical failures in the 'ZL' panel, accomplish the following within the next 90 days after the effective date of this AD unless previously accomplished: A. Replace the two existing 80 amp fuses on the 'ZL' panel with 100 amp fuses, in accordance with the Accomplishment Instructions of British Aerospace 125 Aircraft Service Bulletin 24-239-(2885), Revision 1, dated February 27, 1984. B. Install covers on the 'ZL' panel as follows: 1. For aircraft that have accomplished STC SA3870WE or STC SA3925WE, in accordance with the Accomplishment Instructions of AiResearch Aviation Company Service Bulletin No. 6-7, dated October 25, 1983. 2. For any other aircraft fitted with Garrett TFE 731-3 engines, in accordance with the Accomplishment Instructions of British Aerospace 125 Aircraft Service Bulletin 24-220-(2749), Revision 3, dated March 3, 1983. C. Alternate means of compliance which provide an equivalent level of safety may be used when approved by the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region. D. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base for the accomplishment of inspections and/or modifications required by this AD. Amendment 39-4932 became effective November 14, 1984. This Amendment 39-4993 becomes effective February 11, 1985. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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