AD 90-01-03
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Bombardier Inc. | Cessna Aircraft Company | Textron Aviation Inc. | Honeywell International Inc. | ATR – GIE Avions de Transport Régional | ATR42-300 | Airworthiness Directives; HONEYWELL, INC., SPERRY COMMERCIAL FLIGHT SYSTEMS GROUP, BUSINESS AND COMMUTER AVIATION SYSTEMS DIVISION (Sperry Corporation) AH-600 Attitude and Heading Reference System (AHRS) Strapdown Attitude and Heading Reference Unit (AHRU), |
| aircraft | Bombardier Inc. | Cessna Aircraft Company | Textron Aviation Inc. | Honeywell International Inc. | ATR – GIE Avions de Transport Régional | DHC-8-101 | Airworthiness Directives; HONEYWELL, INC., SPERRY COMMERCIAL FLIGHT SYSTEMS GROUP, BUSINESS AND COMMUTER AVIATION SYSTEMS DIVISION (Sperry Corporation) AH-600 Attitude and Heading Reference System (AHRS) Strapdown Attitude and Heading Reference Unit (AHRU), |
| aircraft | Bombardier Inc. | Cessna Aircraft Company | Textron Aviation Inc. | Honeywell International Inc. | ATR – GIE Avions de Transport Régional | DHC-8-102 | Airworthiness Directives; HONEYWELL, INC., SPERRY COMMERCIAL FLIGHT SYSTEMS GROUP, BUSINESS AND COMMUTER AVIATION SYSTEMS DIVISION (Sperry Corporation) AH-600 Attitude and Heading Reference System (AHRS) Strapdown Attitude and Heading Reference Unit (AHRU), |
| aircraft | Bombardier Inc. | Cessna Aircraft Company | Textron Aviation Inc. | Honeywell International Inc. | ATR – GIE Avions de Transport Régional | DHC-8-103 | Airworthiness Directives; HONEYWELL, INC., SPERRY COMMERCIAL FLIGHT SYSTEMS GROUP, BUSINESS AND COMMUTER AVIATION SYSTEMS DIVISION (Sperry Corporation) AH-600 Attitude and Heading Reference System (AHRS) Strapdown Attitude and Heading Reference Unit (AHRU), |
| aircraft | Bombardier Inc. | Cessna Aircraft Company | Textron Aviation Inc. | Honeywell International Inc. | ATR – GIE Avions de Transport Régional | DHC-8-106 | Airworthiness Directives; HONEYWELL, INC., SPERRY COMMERCIAL FLIGHT SYSTEMS GROUP, BUSINESS AND COMMUTER AVIATION SYSTEMS DIVISION (Sperry Corporation) AH-600 Attitude and Heading Reference System (AHRS) Strapdown Attitude and Heading Reference Unit (AHRU), |
| aircraft | Bombardier Inc. | Cessna Aircraft Company | Textron Aviation Inc. | Honeywell International Inc. | ATR – GIE Avions de Transport Régional | DHC-8-201 | Airworthiness Directives; HONEYWELL, INC., SPERRY COMMERCIAL FLIGHT SYSTEMS GROUP, BUSINESS AND COMMUTER AVIATION SYSTEMS DIVISION (Sperry Corporation) AH-600 Attitude and Heading Reference System (AHRS) Strapdown Attitude and Heading Reference Unit (AHRU), |
| aircraft | Bombardier Inc. | Cessna Aircraft Company | Textron Aviation Inc. | Honeywell International Inc. | ATR – GIE Avions de Transport Régional | DHC-8-202 | Airworthiness Directives; HONEYWELL, INC., SPERRY COMMERCIAL FLIGHT SYSTEMS GROUP, BUSINESS AND COMMUTER AVIATION SYSTEMS DIVISION (Sperry Corporation) AH-600 Attitude and Heading Reference System (AHRS) Strapdown Attitude and Heading Reference Unit (AHRU), |
| aircraft | Bombardier Inc. | Cessna Aircraft Company | Textron Aviation Inc. | Honeywell International Inc. | ATR – GIE Avions de Transport Régional | DHC-8-301 | Airworthiness Directives; HONEYWELL, INC., SPERRY COMMERCIAL FLIGHT SYSTEMS GROUP, BUSINESS AND COMMUTER AVIATION SYSTEMS DIVISION (Sperry Corporation) AH-600 Attitude and Heading Reference System (AHRS) Strapdown Attitude and Heading Reference Unit (AHRU), |
| aircraft | Bombardier Inc. | Cessna Aircraft Company | Textron Aviation Inc. | Honeywell International Inc. | ATR – GIE Avions de Transport Régional | DHC-8-311 | Airworthiness Directives; HONEYWELL, INC., SPERRY COMMERCIAL FLIGHT SYSTEMS GROUP, BUSINESS AND COMMUTER AVIATION SYSTEMS DIVISION (Sperry Corporation) AH-600 Attitude and Heading Reference System (AHRS) Strapdown Attitude and Heading Reference Unit (AHRU), |
| aircraft | Bombardier Inc. | Cessna Aircraft Company | Textron Aviation Inc. | Honeywell International Inc. | ATR – GIE Avions de Transport Régional | DHC-8-315 | Airworthiness Directives; HONEYWELL, INC., SPERRY COMMERCIAL FLIGHT SYSTEMS GROUP, BUSINESS AND COMMUTER AVIATION SYSTEMS DIVISION (Sperry Corporation) AH-600 Attitude and Heading Reference System (AHRS) Strapdown Attitude and Heading Reference Unit (AHRU), |
| appliance | Bombardier Inc. | Cessna Aircraft Company | Textron Aviation Inc. | Honeywell International Inc. | ATR – GIE Avions de Transport Régional | ATR42-300 | Airworthiness Directives; HONEYWELL, INC., SPERRY COMMERCIAL FLIGHT SYSTEMS GROUP, BUSINESS AND COMMUTER AVIATION SYSTEMS DIVISION (Sperry Corporation) AH-600 Attitude and Heading Reference System (AHRS) Strapdown Attitude and Heading Reference Unit (AHRU), |
| appliance | Bombardier Inc. | Cessna Aircraft Company | Textron Aviation Inc. | Honeywell International Inc. | ATR – GIE Avions de Transport Régional | DHC-8-101 | Airworthiness Directives; HONEYWELL, INC., SPERRY COMMERCIAL FLIGHT SYSTEMS GROUP, BUSINESS AND COMMUTER AVIATION SYSTEMS DIVISION (Sperry Corporation) AH-600 Attitude and Heading Reference System (AHRS) Strapdown Attitude and Heading Reference Unit (AHRU), |
| appliance | Bombardier Inc. | Cessna Aircraft Company | Textron Aviation Inc. | Honeywell International Inc. | ATR – GIE Avions de Transport Régional | DHC-8-102 | Airworthiness Directives; HONEYWELL, INC., SPERRY COMMERCIAL FLIGHT SYSTEMS GROUP, BUSINESS AND COMMUTER AVIATION SYSTEMS DIVISION (Sperry Corporation) AH-600 Attitude and Heading Reference System (AHRS) Strapdown Attitude and Heading Reference Unit (AHRU), |
| appliance | Bombardier Inc. | Cessna Aircraft Company | Textron Aviation Inc. | Honeywell International Inc. | ATR – GIE Avions de Transport Régional | DHC-8-103 | Airworthiness Directives; HONEYWELL, INC., SPERRY COMMERCIAL FLIGHT SYSTEMS GROUP, BUSINESS AND COMMUTER AVIATION SYSTEMS DIVISION (Sperry Corporation) AH-600 Attitude and Heading Reference System (AHRS) Strapdown Attitude and Heading Reference Unit (AHRU), |
| appliance | Bombardier Inc. | Cessna Aircraft Company | Textron Aviation Inc. | Honeywell International Inc. | ATR – GIE Avions de Transport Régional | DHC-8-106 | Airworthiness Directives; HONEYWELL, INC., SPERRY COMMERCIAL FLIGHT SYSTEMS GROUP, BUSINESS AND COMMUTER AVIATION SYSTEMS DIVISION (Sperry Corporation) AH-600 Attitude and Heading Reference System (AHRS) Strapdown Attitude and Heading Reference Unit (AHRU), |
| appliance | Bombardier Inc. | Cessna Aircraft Company | Textron Aviation Inc. | Honeywell International Inc. | ATR – GIE Avions de Transport Régional | DHC-8-201 | Airworthiness Directives; HONEYWELL, INC., SPERRY COMMERCIAL FLIGHT SYSTEMS GROUP, BUSINESS AND COMMUTER AVIATION SYSTEMS DIVISION (Sperry Corporation) AH-600 Attitude and Heading Reference System (AHRS) Strapdown Attitude and Heading Reference Unit (AHRU), |
| appliance | Bombardier Inc. | Cessna Aircraft Company | Textron Aviation Inc. | Honeywell International Inc. | ATR – GIE Avions de Transport Régional | DHC-8-202 | Airworthiness Directives; HONEYWELL, INC., SPERRY COMMERCIAL FLIGHT SYSTEMS GROUP, BUSINESS AND COMMUTER AVIATION SYSTEMS DIVISION (Sperry Corporation) AH-600 Attitude and Heading Reference System (AHRS) Strapdown Attitude and Heading Reference Unit (AHRU), |
| appliance | Bombardier Inc. | Cessna Aircraft Company | Textron Aviation Inc. | Honeywell International Inc. | ATR – GIE Avions de Transport Régional | DHC-8-301 | Airworthiness Directives; HONEYWELL, INC., SPERRY COMMERCIAL FLIGHT SYSTEMS GROUP, BUSINESS AND COMMUTER AVIATION SYSTEMS DIVISION (Sperry Corporation) AH-600 Attitude and Heading Reference System (AHRS) Strapdown Attitude and Heading Reference Unit (AHRU), |
| appliance | Bombardier Inc. | Cessna Aircraft Company | Textron Aviation Inc. | Honeywell International Inc. | ATR – GIE Avions de Transport Régional | DHC-8-311 | Airworthiness Directives; HONEYWELL, INC., SPERRY COMMERCIAL FLIGHT SYSTEMS GROUP, BUSINESS AND COMMUTER AVIATION SYSTEMS DIVISION (Sperry Corporation) AH-600 Attitude and Heading Reference System (AHRS) Strapdown Attitude and Heading Reference Unit (AHRU), |
| appliance | Bombardier Inc. | Cessna Aircraft Company | Textron Aviation Inc. | Honeywell International Inc. | ATR – GIE Avions de Transport Régional | DHC-8-315 | Airworthiness Directives; HONEYWELL, INC., SPERRY COMMERCIAL FLIGHT SYSTEMS GROUP, BUSINESS AND COMMUTER AVIATION SYSTEMS DIVISION (Sperry Corporation) AH-600 Attitude and Heading Reference System (AHRS) Strapdown Attitude and Heading Reference Unit (AHRU), |
| appliance | Bombardier Inc. | Cessna Aircraft Company | Textron Aviation Inc. | Honeywell International Inc. | ATR – GIE Avions de Transport Régional | DHC-8-400 | Airworthiness Directives; HONEYWELL, INC., SPERRY COMMERCIAL FLIGHT SYSTEMS GROUP, BUSINESS AND COMMUTER AVIATION SYSTEMS DIVISION (Sperry Corporation) AH-600 Attitude and Heading Reference System (AHRS) Strapdown Attitude and Heading Reference Unit (AHRU), |
| appliance | Bombardier Inc. | Cessna Aircraft Company | Textron Aviation Inc. | Honeywell International Inc. | ATR – GIE Avions de Transport Régional | DHC-8-401 | Airworthiness Directives; HONEYWELL, INC., SPERRY COMMERCIAL FLIGHT SYSTEMS GROUP, BUSINESS AND COMMUTER AVIATION SYSTEMS DIVISION (Sperry Corporation) AH-600 Attitude and Heading Reference System (AHRS) Strapdown Attitude and Heading Reference Unit (AHRU), |
| appliance | Bombardier Inc. | Cessna Aircraft Company | Textron Aviation Inc. | Honeywell International Inc. | ATR – GIE Avions de Transport Régional | DHC-8-402 | Airworthiness Directives; HONEYWELL, INC., SPERRY COMMERCIAL FLIGHT SYSTEMS GROUP, BUSINESS AND COMMUTER AVIATION SYSTEMS DIVISION (Sperry Corporation) AH-600 Attitude and Heading Reference System (AHRS) Strapdown Attitude and Heading Reference Unit (AHRU), |
| appliance | Bombardier Inc. | Cessna Aircraft Company | Textron Aviation Inc. | Honeywell International Inc. | ATR – GIE Avions de Transport Régional | 650 | Airworthiness Directives; HONEYWELL, INC., SPERRY COMMERCIAL FLIGHT SYSTEMS GROUP, BUSINESS AND COMMUTER AVIATION SYSTEMS DIVISION (Sperry Corporation) AH-600 Attitude and Heading Reference System (AHRS) Strapdown Attitude and Heading Reference Unit (AHRU), |
| appliance | Bombardier Inc. | Cessna Aircraft Company | Textron Aviation Inc. | Honeywell International Inc. | ATR – GIE Avions de Transport Régional | BAe.125 Series 800A | Airworthiness Directives; HONEYWELL, INC., SPERRY COMMERCIAL FLIGHT SYSTEMS GROUP, BUSINESS AND COMMUTER AVIATION SYSTEMS DIVISION (Sperry Corporation) AH-600 Attitude and Heading Reference System (AHRS) Strapdown Attitude and Heading Reference Unit (AHRU), |
| appliance | Bombardier Inc. | Cessna Aircraft Company | Textron Aviation Inc. | Honeywell International Inc. | ATR – GIE Avions de Transport Régional | BAe.125 Series 800A (C-29A) | Airworthiness Directives; HONEYWELL, INC., SPERRY COMMERCIAL FLIGHT SYSTEMS GROUP, BUSINESS AND COMMUTER AVIATION SYSTEMS DIVISION (Sperry Corporation) AH-600 Attitude and Heading Reference System (AHRS) Strapdown Attitude and Heading Reference Unit (AHRU), |
| appliance | Bombardier Inc. | Cessna Aircraft Company | Textron Aviation Inc. | Honeywell International Inc. | ATR – GIE Avions de Transport Régional | BAe.125 Series 800A (U-125) | Airworthiness Directives; HONEYWELL, INC., SPERRY COMMERCIAL FLIGHT SYSTEMS GROUP, BUSINESS AND COMMUTER AVIATION SYSTEMS DIVISION (Sperry Corporation) AH-600 Attitude and Heading Reference System (AHRS) Strapdown Attitude and Heading Reference Unit (AHRU), |
| appliance | Bombardier Inc. | Cessna Aircraft Company | Textron Aviation Inc. | Honeywell International Inc. | ATR – GIE Avions de Transport Régional | BAe.125 Series 800B | Airworthiness Directives; HONEYWELL, INC., SPERRY COMMERCIAL FLIGHT SYSTEMS GROUP, BUSINESS AND COMMUTER AVIATION SYSTEMS DIVISION (Sperry Corporation) AH-600 Attitude and Heading Reference System (AHRS) Strapdown Attitude and Heading Reference Unit (AHRU), |
| appliance | Bombardier Inc. | Cessna Aircraft Company | Textron Aviation Inc. | Honeywell International Inc. | ATR – GIE Avions de Transport Régional | Attitude and Heading Reference System | Airworthiness Directives; HONEYWELL, INC., SPERRY COMMERCIAL FLIGHT SYSTEMS GROUP, BUSINESS AND COMMUTER AVIATION SYSTEMS DIVISION (Sperry Corporation) AH-600 Attitude and Heading Reference System (AHRS) Strapdown Attitude and Heading Reference Unit (AHRU), |
Unsafe Condition
The possibility of the primary attitude and heading displays on both sides of the instrument panel failing simultaneously.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect airplanes with Honeywell AH-600 AHRS installed to determine part number, serial number, and Mod Level of the AHRU in pilot's (Number 1), copilot's (Number 2), and auxiliary (Number 3) AHRS. Remove AHRUs with part numbers 7003360-931 through -936, serial numbers 0100 through 0277, without Mod Level 'F', from service. Install part numbers with Mod Level 'F' or modify per Honeywell Service Bulletin 7003360-34-32.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within 10 days after January 9, 1989 (the effective date of Amendment 39-6093) for pilot's AHRS; within 60 calendar days after February 5, 1990 (effective date of this amendment) for copilot's and auxiliary AHRS, with removal within 45 days after inspection.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Honeywell AH-600 AHRS Strapdown AHRU part numbers 7003360-931 through -936, serial numbers 0100 through 0277, installed in de Havilland DHC-8, British Aerospace BAe 125-800, Cessna 650, and Aerospatiale ATR42-300 series airplanes.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Attitude and Heading Reference System
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_90-01-03.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 90-01-03 Document Type: AD Final Rules Docket Number: 89-NM-98-AD Subject Heading: Airworthiness Directives; HONEYWELL, INC., SPERRY COMMERCIAL FLIGHT SYSTEMS GROUP, BUSINESS AND CO...Show more Subject: Attitude and Heading Reference System Status: Current Citation: This information is not available. Citation Publish Date: 01/04/1990 Effective Date: 02/05/1990 Make: Bombardier Inc. | Cessna Aircraft Company | Textron Aviation Inc. | Honeywell International Inc. | A...Show more Model: ATR42-300 | DHC-8-101 | DHC-8-102 | DHC-8-103 | DHC-8-106 | DHC-8-201 | DHC-8-202 | DHC-8-301 | DHC-...Show more Product Type: Appliance Product Subtype: Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: AIR-700: Compliance & Airworthiness Division Office of Primary Responsibility: AIR-730: International Validation Branch CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 90-01-03 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: 89-NM-98-AD AMENDMENT: 39-6442 AD NUMBER: 90-01-03 SUBJECT HEADING: Airworthiness Directives; HONEYWELL, INC., SPERRY COMMERCIAL FLIGHT SYSTEMS GROUP, BUSINESS AND COMMUTER AVIATION SYSTEMS DIVISION (Sperry Corporation) AH-600 Attitude and Heading Reference System (AHRS) Strapdown Attitude and Heading Reference Unit (AHRU), ACTION: SUMMARY: DATES: Effective February 5, 1990. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 90-01-03 HONEYWELL, INC., SPERRY COMMERCIAL FLIGHT SYSTEMS GROUP, BUSINESS AND COMMUTER AVIATION SYSTEMS DIVISION (Sperry Corporation): Amendment 39-6442. Docket No. 89-NM-98-AD. Applicability: Honeywell AH-600 Attitude and Heading Reference System (AHRS) Strapdown Attitude and Heading Reference Unit (AHRU), part numbers 7003360-931, -932, -933, -934, -935, and -936, with serial numbers 0100 through 0277. Compliance: Required as indicated, unless previously accomplished. NOTE: These systems are known to be installed in, but not limited to, de Havilland Model DHC-8, British Aerospace Model BAe 125-800, Cessna Model 650, and Aerospatiale Model ATR42-300 series airplanes. To eliminate the possibility of the primary attitude and heading displays on both sides of the instrument panel failing simultaneously, accomplish the following: A. Within 10 days after January 9, 1989 (the effective date of Amendment 39-6093), inspect airplanes with Honeywell AH-600 AHRS installed to determine the part number, serial number, and Mod Level of the strapdown AHRU installed in the pilot's (Number 1) AHRS. Prior to further flight after inspection, remove all AHRU part numbers 7003360-931, -932, -933, -934, -935, and -936 with serial numbers 0100 through 0277, without Mod Level "F", from service in the pilot's (Number 1) AHRS. Install the same part number with Mod Level "F" incorporated, or modify the AHRU in accordance with Honeywell Inc., Service Bulletin 7003360-34-32, dated August 2, 1988. NOTE: Serial numbers of the strapdown AHRU are eight digit numbers; the first four are date code and the last four are the individual unit identifier. Serial numbers referred to in this AD are the last four numbers of the serial number. B. Within 60 calendar days after the effective date of this amendment, inspect airplanes with Honeywell AH-600 AHRS installed to determine the part number, serial number, and Mod Level of the strapdown AHRU installed in copilot's (Number 2) AHRS and the auxiliary (Number 3) AHRS. Within 45 days after the inspection, remove all AHRU part numbers 7003360-931, -932, -933, -934, -935, and -936, with serial numbers 0100 through 0277, without Mod Level "F", from service in the copilot's (Number 2) AHRS and the auxiliary (Number 3) AHRS. Install the same part number with Mod Level "F" incorporated, or modify the AHRU in accordance with Honeywell, Inc., Service Bulletin 7003360-34-32, dated August 2, 1988. C. An alternate means of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, Los Angeles Aircraft Certification Office, FAA, Northwest Mountain Region. NOTE: The request should be forwarded through an FAA Principal Maintenance Inspector (PMI), who will either concur or comment, and then send it to the Manager, Los Angeles Aircraft Certification Office. D. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base in order to comply with the requirements of this AD. All persons affected by this directive who have not already received the appropriate service documents from the manufacturer may obtain copies upon request to Honeywell Inc., Sperry Commercial Flight Systems Group, Business and Commuter Aviation Systems Division, 5353 West Bell Road, Glendale, Arizona 85308. These documents may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 17900 Pacific Highway South, Seattle, Washington, or at the Los Angeles Aircraft Certification Office, 3229 East Spring Street, Long Beach, California. This AD supersedes AD 88-26-05, Amendment 39-6093. This amendment (39-6442, AD 90-01-03) becomes effective on February 5, 1990. FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_90-01-03.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 90-01-03 Document Type: AD Final Rules Docket Number: 89-NM-98-AD Subject Heading: Airworthiness Directives; HONEYWELL, INC., SPERRY COMMERCIAL FLIGHT SYSTEMS GROUP, BUSINESS AND CO...Show more Subject: Attitude and Heading Reference System Status: Current Citation: This information is not available. Citation Publish Date: 01/04/1990 Effective Date: 02/05/1990 Make: Bombardier Inc. | Cessna Aircraft Company | Textron Aviation Inc. | Honeywell International Inc. | A...Show more Model: ATR42-300 | DHC-8-101 | DHC-8-102 | DHC-8-103 | DHC-8-106 | DHC-8-201 | DHC-8-202 | DHC-8-301 | DHC-...Show more Product Type: Appliance Product Subtype: Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: AIR-700: Compliance & Airworthiness Division Office of Primary Responsibility: AIR-730: International Validation Branch CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 90-01-03 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: 89-NM-98-AD AMENDMENT: 39-6442 AD NUMBER: 90-01-03 SUBJECT HEADING: Airworthiness Directives; HONEYWELL, INC., SPERRY COMMERCIAL FLIGHT SYSTEMS GROUP, BUSINESS AND COMMUTER AVIATION SYSTEMS DIVISION (Sperry Corporation) AH-600 Attitude and Heading Reference System (AHRS) Strapdown Attitude and Heading Reference Unit (AHRU), ACTION: SUMMARY: DATES: Effective February 5, 1990. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 90-01-03 HONEYWELL, INC., SPERRY COMMERCIAL FLIGHT SYSTEMS GROUP, BUSINESS AND COMMUTER AVIATION SYSTEMS DIVISION (Sperry Corporation): Amendment 39-6442. Docket No. 89-NM-98-AD. Applicability: Honeywell AH-600 Attitude and Heading Reference System (AHRS) Strapdown Attitude and Heading Reference Unit (AHRU), part numbers 7003360-931, -932, -933, -934, -935, and -936, with serial numbers 0100 through 0277. Compliance: Required as indicated, unless previously accomplished. NOTE: These systems are known to be installed in, but not limited to, de Havilland Model DHC-8, British Aerospace Model BAe 125-800, Cessna Model 650, and Aerospatiale Model ATR42-300 series airplanes. To eliminate the possibility of the primary attitude and heading displays on both sides of the instrument panel failing simultaneously, accomplish the following: A. Within 10 days after January 9, 1989 (the effective date of Amendment 39-6093), inspect airplanes with Honeywell AH-600 AHRS installed to determine the part number, serial number, and Mod Level of the strapdown AHRU installed in the pilot's (Number 1) AHRS. Prior to further flight after inspection, remove all AHRU part numbers 7003360-931, -932, -933, -934, -935, and -936 with serial numbers 0100 through 0277, without Mod Level "F", from service in the pilot's (Number 1) AHRS. Install the same part number with Mod Level "F" incorporated, or modify the AHRU in accordance with Honeywell Inc., Service Bulletin 7003360-34-32, dated August 2, 1988. NOTE: Serial numbers of the strapdown AHRU are eight digit numbers; the first four are date code and the last four are the individual unit identifier. Serial numbers referred to in this AD are the last four numbers of the serial number. B. Within 60 calendar days after the effective date of this amendment, inspect airplanes with Honeywell AH-600 AHRS installed to determine the part number, serial number, and Mod Level of the strapdown AHRU installed in copilot's (Number 2) AHRS and the auxiliary (Number 3) AHRS. Within 45 days after the inspection, remove all AHRU part numbers 7003360-931, -932, -933, -934, -935, and -936, with serial numbers 0100 through 0277, without Mod Level "F", from service in the copilot's (Number 2) AHRS and the auxiliary (Number 3) AHRS. Install the same part number with Mod Level "F" incorporated, or modify the AHRU in accordance with Honeywell, Inc., Service Bulletin 7003360-34-32, dated August 2, 1988. C. An alternate means of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, Los Angeles Aircraft Certification Office, FAA, Northwest Mountain Region. NOTE: The request should be forwarded through an FAA Principal Maintenance Inspector (PMI), who will either concur or comment, and then send it to the Manager, Los Angeles Aircraft Certification Office. D. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base in order to comply with the requirements of this AD. All persons affected by this directive who have not already received the appropriate service documents from the manufacturer may obtain copies upon request to Honeywell Inc., Sperry Commercial Flight Systems Group, Business and Commuter Aviation Systems Division, 5353 West Bell Road, Glendale, Arizona 85308. These documents may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 17900 Pacific Highway South, Seattle, Washington, or at the Los Angeles Aircraft Certification Office, 3229 East Spring Street, Long Beach, California. This AD supersedes AD 88-26-05, Amendment 39-6093. This amendment (39-6442, AD 90-01-03) becomes effective on February 5, 1990. FOOTER:
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Rights: U.S. Government Public Domain
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