AD 66-07-01
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | The Boeing Company | 707-100 Long Body | BOEING Models 707, 720 and 720B Series Airplanes |
| aircraft | The Boeing Company | 707-100B Long Body | BOEING Models 707, 720 and 720B Series Airplanes |
| aircraft | The Boeing Company | 707-100B Short Body | BOEING Models 707, 720 and 720B Series Airplanes |
| aircraft | The Boeing Company | 707-200 | BOEING Models 707, 720 and 720B Series Airplanes |
| aircraft | The Boeing Company | 707-300 Series | BOEING Models 707, 720 and 720B Series Airplanes |
| aircraft | The Boeing Company | 707-300B Series | BOEING Models 707, 720 and 720B Series Airplanes |
| aircraft | The Boeing Company | 707-300C Series | BOEING Models 707, 720 and 720B Series Airplanes |
| aircraft | The Boeing Company | 707-400 Series | BOEING Models 707, 720 and 720B Series Airplanes |
| aircraft | The Boeing Company | 720 Series | BOEING Models 707, 720 and 720B Series Airplanes |
| aircraft | The Boeing Company | 720B Series | BOEING Models 707, 720 and 720B Series Airplanes |
Unsafe Condition
Failure of the main landing gear rear axles due to hydrogen embrittlement or stress corrosion.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Within 800 hours' time in service after the AD's effective date, inspect the main landing gear aft axle for corrosion or inadequate lubrication, remove corrosion, grease the axle, and before further flight. At each aft wheel brake change, repeat inspection. Inspect chrome-plated axles for cracks, remove chrome plate and rework defects if found. Do not chrome plate axles after the AD's effective date.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within the next 800 hours' time in service after the effective date of this AD, unless already accomplished, and thereafter at each aft wheel brake change.
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Affected Aircraft
Boeing Models 707, 720, and 720B Series airplanes except those with axles modified per Boeing Service Bulletin 2028, 2221, 2246, or specific models like 707-121B, 707-139B, 707-131B, 707-300B, 707-300C Series, or modified with 4 Brake Rod configuration.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Main Landing Gear Rear Axles
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_66-07-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 66-07-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: BOEING Models 707, 720 and 720B Series Airplanes Subject: Main Landing Gear Rear Axles Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 12/16/1966 Make: The Boeing Company Model: 707-100 Long Body | 707-100B Long Body | 707-100B Short Body | 707-200 | 707-300 Series | 707-300B S...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: 66-07-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-204 AD NUMBER: 66-07-01 SUBJECT HEADING: BOEING Models 707, 720 and 720B Series Airplanes ACTION: SUMMARY: DATES: Effective December 16, 1966. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 66-07-01 BOEING: Amdt. 39-204 Part 39 Federal Register March 5, 1966. Applies to Models 707, 720 and 720B Series Airplanes, except Models 707-100 and 707-200 Series Airplanes With Axles Modified in Accordance With Paragraph 3, "Modification Data," of Boeing Service Bulletin 2028, or Later FAA-Approved Revision; Models 707-300, 707-400, 720, and 720B Series Airplanes with Axles Modified in Accordance With the Optional Rework Procedure of Boeing Service Bulletin No. 2221, or Later FAA-Approved Revision; Models 707-100, 707-100B, 707-200, 720 and 720B Series Airplanes with Axles Replaced in Accordance with Boeing Service Bulletin No. 2246, or Later FAA-Approved Revision; Model 707-121B; Model 707-139B; Model 707-131B; Model 707-300B Series Airplanes; Model 707-300C Series Airplanes; and Airplanes Modified to Incorporate Landing Gears With the 4 Brake Rod (Equalized Gear) Configuration. Compliance required as indicated. To prevent further failures of the main landing gear rear axles due to hydrogen embrittlement or stress corrosion, accomplish the following: (a) Within the next 800 hours' time in service after the effective date of this AD, unless already accomplished, and thereafter at each aft wheel brake change, accomplish the following: (1) Visually inspect the main landing gear aft axle for corrosion or inadequate lubrication in the region of the brake collar in accordance with paragraph 3, "Inspection Data" of Boeing Service Bulletin 1378 or later FAA-approved revision or an equivalent approved by the Aircraft Engineering Division, FAA Western Region. Remove any corrosion from the axle using the procedure described in the "NOTE" following paragraph 3.d. of Boeing Service Bulletin No. 1378 or later FAA-approved revision and grease the axle as described in paragraph 3.e. of Boeing Service Bulletin 1378 or later FAA-approved revision, before further flight. (2) On Models 707-100 and -200 Series airplanes with axles reworked by chrome plating, visually inspect for cracks in the chrome plating, as described in paragraph 3, "Inspection Data" of Boeing Service Bulletin No. 1902 or later FAA-approved revision. If cracks in the chrome plating are found, remove the chrome plate, and rework any defects found in the base metal, before further flight in accordance with the "NOTE" following paragraph 3.d. of Boeing Service Bulletin No. 1902 or later FAA-approved revision applying the rework limits specified in Boeing Service Bulletin No. 1378. (b) After the effective date of this AD, do not chrome plate the axle, Boeing P/N's 50- 9720, 50-9720-1 and 50-9720-1S, in the area of the inner bearing for the brake collar on 707-100 and -200 Series airplanes. Axles that have been chrome plated before the effective date of this AD may be continued in service. (c) Upon request of an operator, an FAA maintenance inspector, with prior approval of the Chief, Aircraft Engineering Division, FAA Western Region, may adjust the repetitive inspection intervals required by this AD to permit compliance at an established inspection period of the operator, if the request contains substantiating data to justify the increase for that operator. This directive effective April 4, 1966. Revised December 16, 1966. FOOTER:
Document Text
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AD Final Rules - DRS_66-07-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 66-07-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: BOEING Models 707, 720 and 720B Series Airplanes Subject: Main Landing Gear Rear Axles Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 12/16/1966 Make: The Boeing Company Model: 707-100 Long Body | 707-100B Long Body | 707-100B Short Body | 707-200 | 707-300 Series | 707-300B S...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: 66-07-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-204 AD NUMBER: 66-07-01 SUBJECT HEADING: BOEING Models 707, 720 and 720B Series Airplanes ACTION: SUMMARY: DATES: Effective December 16, 1966. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 66-07-01 BOEING: Amdt. 39-204 Part 39 Federal Register March 5, 1966. Applies to Models 707, 720 and 720B Series Airplanes, except Models 707-100 and 707-200 Series Airplanes With Axles Modified in Accordance With Paragraph 3, "Modification Data," of Boeing Service Bulletin 2028, or Later FAA-Approved Revision; Models 707-300, 707-400, 720, and 720B Series Airplanes with Axles Modified in Accordance With the Optional Rework Procedure of Boeing Service Bulletin No. 2221, or Later FAA-Approved Revision; Models 707-100, 707-100B, 707-200, 720 and 720B Series Airplanes with Axles Replaced in Accordance with Boeing Service Bulletin No. 2246, or Later FAA-Approved Revision; Model 707-121B; Model 707-139B; Model 707-131B; Model 707-300B Series Airplanes; Model 707-300C Series Airplanes; and Airplanes Modified to Incorporate Landing Gears With the 4 Brake Rod (Equalized Gear) Configuration. Compliance required as indicated. To prevent further failures of the main landing gear rear axles due to hydrogen embrittlement or stress corrosion, accomplish the following: (a) Within the next 800 hours' time in service after the effective date of this AD, unless already accomplished, and thereafter at each aft wheel brake change, accomplish the following: (1) Visually inspect the main landing gear aft axle for corrosion or inadequate lubrication in the region of the brake collar in accordance with paragraph 3, "Inspection Data" of Boeing Service Bulletin 1378 or later FAA-approved revision or an equivalent approved by the Aircraft Engineering Division, FAA Western Region. Remove any corrosion from the axle using the procedure described in the "NOTE" following paragraph 3.d. of Boeing Service Bulletin No. 1378 or later FAA-approved revision and grease the axle as described in paragraph 3.e. of Boeing Service Bulletin 1378 or later FAA-approved revision, before further flight. (2) On Models 707-100 and -200 Series airplanes with axles reworked by chrome plating, visually inspect for cracks in the chrome plating, as described in paragraph 3, "Inspection Data" of Boeing Service Bulletin No. 1902 or later FAA-approved revision. If cracks in the chrome plating are found, remove the chrome plate, and rework any defects found in the base metal, before further flight in accordance with the "NOTE" following paragraph 3.d. of Boeing Service Bulletin No. 1902 or later FAA-approved revision applying the rework limits specified in Boeing Service Bulletin No. 1378. (b) After the effective date of this AD, do not chrome plate the axle, Boeing P/N's 50- 9720, 50-9720-1 and 50-9720-1S, in the area of the inner bearing for the brake collar on 707-100 and -200 Series airplanes. Axles that have been chrome plated before the effective date of this AD may be continued in service. (c) Upon request of an operator, an FAA maintenance inspector, with prior approval of the Chief, Aircraft Engineering Division, FAA Western Region, may adjust the repetitive inspection intervals required by this AD to permit compliance at an established inspection period of the operator, if the request contains substantiating data to justify the increase for that operator. This directive effective April 4, 1966. Revised December 16, 1966. FOOTER:
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Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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