AD 69-26-08
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Lockheed Martin Corporation | 188A | LOCKHEED Model L-188 Series Airplanes |
| aircraft | Lockheed Martin Corporation | 188C | LOCKHEED Model L-188 Series Airplanes |
Unsafe Condition
The takeoff warning system may not arm at ambient temperatures below 23 degrees F, potentially failing to alert pilots during takeoff power settings at lower temperatures.
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Required Actions
Install a cockpit placard within 50 hours time in service stating the system won't arm below 23°F. Modify the arming switches within 3000 hours time in service to arm at 68-70°F power lever advancement per SB 88/SB-672 or equivalent.
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Compliance Time
Within 50 hours time in service after the effective date of this AD for the placard installation, and within 3000 hours time in service for the arming switches modification.
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Affected Aircraft
Lockheed L-188 airplanes listed in Service Bulletin 88/5B-672 or later FAA-approved revisions, and any other L-188 with the takeoff warning system installed.
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Federal Register Abstract
Takeoff Warning System
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_69-26-08.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 69-26-08 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: LOCKHEED Model L-188 Series Airplanes Subject: Takeoff Warning System Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 01/10/1970 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Lockheed Martin Corporation Model: 188A | 188C Product Type: Aircraft Product Subtype: Large Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 69-26-08 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-904 AD NUMBER: 69-26-08 SUBJECT HEADING: LOCKHEED Model L-188 Series Airplanes ACTION: SUMMARY: DATES: Effective on January 10, 1970. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 69-26-08 LOCKHEED: L-188 Series Airplanes. Amdt. 39-904. Applies to Lockheed L-188 airplanes listed in Lockheed Service Bulletin 88/5B-672, dated 10 November 1969, or later FAA approved revisions, and to any other L-188 airplane which has the Lockheed takeoff warning system installed. Compliance required as indicated. To provide for arming the aural takeoff warning system at lower ambient temperatures, and to provide interim placard information to the flight crew on the present ambient temperature at which the system will not be armed, accomplish the following: (a) Within 50 hours time in service after the effective date of this AD install a placard in the cockpit in full view of the pilot to read: "Takeoff aural warning system will not be armed when setting takeoff power at ambient temperatures below 23 degrees F" This placard may be removed when Item (b) is accomplished. (b) Within 3000 hours time in service, unless previously accomplished modify the arming switches installation in the takeoff warning system to provide for arming the switches at about 68 degrees-70 degrees power lever advancement in accordance with Lockheed Service Bulletin 88/SB-672 dated November 10, 1969, or later FAA approved revisions, or an equivalent modification approved by the Chief, Aircraft Engineering Division, FAA Western Region. This amendment becomes effective on January 10, 1970. FOOTER:
Document Text
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AD Final Rules - DRS_69-26-08.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 69-26-08 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: LOCKHEED Model L-188 Series Airplanes Subject: Takeoff Warning System Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 01/10/1970 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: 69-26-08 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-904 AD NUMBER: 69-26-08 SUBJECT HEADING: LOCKHEED Model L-188 Series Airplanes ACTION: SUMMARY: DATES: Effective on January 10, 1970. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 69-26-08 LOCKHEED: L-188 Series Airplanes. Amdt. 39-904. Applies to Lockheed L-188 airplanes listed in Lockheed Service Bulletin 88/5B-672, dated 10 November 1969, or later FAA approved revisions, and to any other L-188 airplane which has the Lockheed takeoff warning system installed. Compliance required as indicated. To provide for arming the aural takeoff warning system at lower ambient temperatures, and to provide interim placard information to the flight crew on the present ambient temperature at which the system will not be armed, accomplish the following: (a) Within 50 hours time in service after the effective date of this AD install a placard in the cockpit in full view of the pilot to read: "Takeoff aural warning system will not be armed when setting takeoff power at ambient temperatures below 23 degrees F" This placard may be removed when Item (b) is accomplished. (b) Within 3000 hours time in service, unless previously accomplished modify the arming switches installation in the takeoff warning system to provide for arming the switches at about 68 degrees-70 degrees power lever advancement in accordance with Lockheed Service Bulletin 88/SB-672 dated November 10, 1969, or later FAA approved revisions, or an equivalent modification approved by the Chief, Aircraft Engineering Division, FAA Western Region. This amendment becomes effective on January 10, 1970. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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