AD 74-25-04
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Lockheed Martin Corporation | 188A | LOCKHEED Model L-188A and L-188C Airplanes |
| aircraft | Lockheed Martin Corporation | 188C | LOCKHEED Model L-188A and L-188C Airplanes |
Unsafe Condition
Failure of the horizontal stabilizer due to fatigue cracks in the front spar at F.S. 1167.
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Required Actions
Perform a visual or eddy current inspection with dye penetrant confirmation of the front spar upper cap bolt hole at B.L. 28 L&R as per Lockheed Service Bulletin No. 88/SB 692. Depending on crack severity, repair or replace the spar cap segment per specified paragraphs of the service bulletin. Repeat inspections at intervals not exceeding 2500 flight hours unless preventive rework is done.
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Compliance Time
Within 300 additional flight hours after January 3, 1975, unless already accomplished within the last 2200 flight hours prior to this AD, and at intervals not to exceed 2500 flight hours thereafter.
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Affected Aircraft
Lockheed Model L-188A and L-188C airplanes certificated in all categories.
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Federal Register Abstract
Horizontal Stabilizer
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_74-25-04.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 74-25-04 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: LOCKHEED Model L-188A and L-188C Airplanes Subject: Horizontal Stabilizer Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 01/03/1975 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Lockheed Martin Corporation Model: 188A | 188C Product Type: Aircraft Product Subtype: Large Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 74-25-04 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-2032 AD NUMBER: 74-25-04 SUBJECT HEADING: LOCKHEED Model L-188A and L-188C Airplanes ACTION: SUMMARY: DATES: Effective January 3, 1975. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 74-25-04 LOCKHEED: Amendment 39-2032. Applies to all Lockheed model L-188A and L-188C airplanes certificated in all categories. Compliance is required as indicated. To prevent possible failure of the horizontal stabilizer due to fatigue cracks in the front spar at F.S. 1167, accomplish the following: (a) Within 300 additional flight hours after the effective date of this A.D., unless already accomplished within the last 2200 flight hours prior to this A.D., and at intervals not to exceed 2500 flight hours thereafter perform a visual or eddy current inspection with dye penetrant confirmation of the front spar upper cap bolt hole at B.L. 28 L&R as depicted in Lockheed Service Bulletin No. 88/SB 692 dated October 30, 1974, by figure 1, view A-A. Perform this inspection per the accomplishment instructions in S.B. 88/SB 692 dated October 30, 1974, or later FAA- approved revisions. (1) If crack development is noted and the crack can be removed with a .50 inch maximum diameter clean up concentric with the bolt hole, accomplish the repair instruction of paragraph 2.E (1) of Service Bulletin 692. (2) If crack development is noted and the crack can be removed with a .84 inch maximum diameter clean up concentric with the bolt hole, accomplish the repair instruction of paragraph 2.E (2) of Service Bulletin 692. (3) Any crack development in the P/N 800344-1 spar cap, which exceeds the limitations of the .84 inch maximum diameter clean up requires the replacement of the spar cap segment per accomplishment instructions of paragraph 2.E (3) of Service Bulletin 692. (4) If the inspections reveal no crack development, repeat the inspection thereafter at intervals not to exceed 2500 flight hours, unless the preventive rework specified in paragraph 2D of Service Bulletin 692 is accomplished. (5) If the repairs or preventive rework listed in items 1 thru 4 are accomplished the repeat inspections at 2500 flight hours may be discontinued. (b) Equivalent inspections and installations may be approved by the Chief, Aircraft Engineering Division, FAA Western Region. (c) Aircraft may be operated per FARs 21.197 and 21.199 to a base for accomplishment of maintenance per this A.D. This amendment is effective January 3, 1975. FOOTER:
Document Text
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AD Final Rules - DRS_74-25-04.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 74-25-04 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: LOCKHEED Model L-188A and L-188C Airplanes Subject: Horizontal Stabilizer Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 01/03/1975 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: 74-25-04 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-2032 AD NUMBER: 74-25-04 SUBJECT HEADING: LOCKHEED Model L-188A and L-188C Airplanes ACTION: SUMMARY: DATES: Effective January 3, 1975. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 74-25-04 LOCKHEED: Amendment 39-2032. Applies to all Lockheed model L-188A and L-188C airplanes certificated in all categories. Compliance is required as indicated. To prevent possible failure of the horizontal stabilizer due to fatigue cracks in the front spar at F.S. 1167, accomplish the following: (a) Within 300 additional flight hours after the effective date of this A.D., unless already accomplished within the last 2200 flight hours prior to this A.D., and at intervals not to exceed 2500 flight hours thereafter perform a visual or eddy current inspection with dye penetrant confirmation of the front spar upper cap bolt hole at B.L. 28 L&R as depicted in Lockheed Service Bulletin No. 88/SB 692 dated October 30, 1974, by figure 1, view A-A. Perform this inspection per the accomplishment instructions in S.B. 88/SB 692 dated October 30, 1974, or later FAA- approved revisions. (1) If crack development is noted and the crack can be removed with a .50 inch maximum diameter clean up concentric with the bolt hole, accomplish the repair instruction of paragraph 2.E (1) of Service Bulletin 692. (2) If crack development is noted and the crack can be removed with a .84 inch maximum diameter clean up concentric with the bolt hole, accomplish the repair instruction of paragraph 2.E (2) of Service Bulletin 692. (3) Any crack development in the P/N 800344-1 spar cap, which exceeds the limitations of the .84 inch maximum diameter clean up requires the replacement of the spar cap segment per accomplishment instructions of paragraph 2.E (3) of Service Bulletin 692. (4) If the inspections reveal no crack development, repeat the inspection thereafter at intervals not to exceed 2500 flight hours, unless the preventive rework specified in paragraph 2D of Service Bulletin 692 is accomplished. (5) If the repairs or preventive rework listed in items 1 thru 4 are accomplished the repeat inspections at 2500 flight hours may be discontinued. (b) Equivalent inspections and installations may be approved by the Chief, Aircraft Engineering Division, FAA Western Region. (c) Aircraft may be operated per FARs 21.197 and 21.199 to a base for accomplishment of maintenance per this A.D. This amendment is effective January 3, 1975. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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