AD 61-09-01
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Lockheed Martin Corporation | 188A | LOCKHEED Model 188 Series Aircraft |
| aircraft | Lockheed Martin Corporation | 188C | LOCKHEED Model 188 Series Aircraft |
Unsafe Condition
Elevator Hydraulic Damper Housing P/N 840655-1 and 475645-1 not identified with blue anodized color may malfunction due to improper dimensions, leading to potential failure in the elevator control system.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Replace or rework the damper housings to specified dimensions (skirt length 0.312±0.010 in, bore 1.3800-1.3817 in, clearance 0.0015-0.0040 in), identify with blue dye or paint, and reinstall per Lockheed Service Letter FS/251702-L.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
not later than the next 50 hours' time in service
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Lockheed Model 188 Series Aircraft with Hydraulic Damper Housing P/N 840655-1 and 475645-1 installed per Service Bulletins 88/SB-524 and 88/SB-532
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Elevator Hydraulic Damper Housing
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_61-09-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 61-09-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: LOCKHEED Model 188 Series Aircraft Subject: Elevator Hydraulic Damper Housing Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 04/07/1961 Make: Lockheed Martin Corporation Model: 188A | 188C Product Type: Aircraft Product Subtype: Large Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 61-09-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 61-09-01 SUBJECT HEADING: LOCKHEED Model 188 Series Aircraft ACTION: SUMMARY: DATES: Effective upon publication in the Federal Register for all persons except those to whom it was made effective immediately by telegram dated April 7, 1961. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 61-09-01 LOCKHEED: Amdt. 279 Part 507 Federal Register April 28, 1961. Applies to All 188 Series Aircraft Which Incorporate Hydraulic Damper Housing P/N's 840655-1 and 475645-1 (rudder, elevator, and aileron control systems) Installed Per Lockheed Service Bulletin 88/SB-524 and 88/SB-532. Compliance required not later than the next 50 hours' time in service. As a result of an incident involving elevator booster hydraulic damper malfunction, hydraulic damper housing P/N 840655-1 and P/N 475645-1 not identified with blue anodized color must be replaced with new parts identified with blue anodized color as received from the manufacturer or reworked to the following dimensions: (a) Length of skirt 0.312 inch plus or minus 0.010 inch. (b) Bore of body 1.3800-1.3817 inches. (c) Clearance between piston and damper housing 0.0015-0.0040 inch. (d) Identify the reworked housing with blue dye or blue paint. The reinstallation of new or reworked damper housings must be accomplished in accordance with instructions in Lockheed Service Letter FS/251702-L dated February 14, 1961. (Lockheed Service Wire to all operators dated April 7, 1961, applies to this same subject.) This directive becomes effective upon publication in the Federal Register for all persons except those to whom it was made effective immediately by telegram dated April 7, 1961. FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_61-09-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 61-09-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: LOCKHEED Model 188 Series Aircraft Subject: Elevator Hydraulic Damper Housing Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 04/07/1961 Make: Lockheed Martin Corporation Model: 188A | 188C 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: 61-09-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 61-09-01 SUBJECT HEADING: LOCKHEED Model 188 Series Aircraft ACTION: SUMMARY: DATES: Effective upon publication in the Federal Register for all persons except those to whom it was made effective immediately by telegram dated April 7, 1961. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 61-09-01 LOCKHEED: Amdt. 279 Part 507 Federal Register April 28, 1961. Applies to All 188 Series Aircraft Which Incorporate Hydraulic Damper Housing P/N's 840655-1 and 475645-1 (rudder, elevator, and aileron control systems) Installed Per Lockheed Service Bulletin 88/SB-524 and 88/SB-532. Compliance required not later than the next 50 hours' time in service. As a result of an incident involving elevator booster hydraulic damper malfunction, hydraulic damper housing P/N 840655-1 and P/N 475645-1 not identified with blue anodized color must be replaced with new parts identified with blue anodized color as received from the manufacturer or reworked to the following dimensions: (a) Length of skirt 0.312 inch plus or minus 0.010 inch. (b) Bore of body 1.3800-1.3817 inches. (c) Clearance between piston and damper housing 0.0015-0.0040 inch. (d) Identify the reworked housing with blue dye or blue paint. The reinstallation of new or reworked damper housings must be accomplished in accordance with instructions in Lockheed Service Letter FS/251702-L dated February 14, 1961. (Lockheed Service Wire to all operators dated April 7, 1961, applies to this same subject.) This directive becomes effective upon publication in the Federal Register for all persons except those to whom it was made effective immediately by telegram dated April 7, 1961. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
This site is not affiliated with or endorsed by the FAA. Always verify with official sources.