AD 73-26-09
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Cessna Aircraft Company | 500 | Airworthiness Directives; CESSNA Model 500 Airplanes |
Unsafe Condition
Cracks in the left and right flight compartment side windows (P/Ns 5511265-3 and -4) at attachment locations could lead to failure of the window panes, compromising pressurization integrity.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect windows using x-ray or visual inspection per Cessna SL56-2 or approved method. Replace unairworthy windows if cracks progress past retainer edges, interconnect three screw holes, exceed three inches in length, or total cracks exceed six inches. Inspect every 100 hours if cracks exist but do not meet replacement criteria. Discontinue requirements after installing P/N 5511285-3/-4 per SB56-4.
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Compliance Time
within the next 25 hours' time in service after October 9, 1974, and thereafter every 200 hours' time in service (or 100 hours if cracks are found but not requiring replacement)
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Affected Aircraft
Cessna Model 500 airplanes (Serial Numbers 500-0001 through 500-0183) with 400 or more hours' time in service.
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Federal Register Abstract
Flight Compartment Side Windows
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_73-26-09.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 73-26-09 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; CESSNA Model 500 Airplanes Subject: Flight Compartment Side Windows Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 10/09/1974 Make: Cessna Aircraft Company Model: 500 Product Type: Aircraft Product Subtype: Large Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 73-26-09 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-1983 AD NUMBER: 73-26-09 SUBJECT HEADING: Airworthiness Directives; CESSNA Model 500 Airplanes ACTION: SUMMARY: DATES: Effective October 9, 1974. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 73-26-09 CESSNA: Amendment 39-1763 as amended by Amendment 39-1983. Applies to Model 500 (Serial Numbers 500-0001 through 500-0183) airplanes, with 400 or more hours' time in service. Compliance: Required as indicated, unless already accomplished. To detect cracks in the left and right flight compartment side windows (P/Ns 5511265-3 and -4), within the next 25 hours' time in service after the effective date of this AD, (on all airplanes with 400 or more hours' time in service) and thereafter at intervals not to exceed 200 hours' time in service, except as provided in Paragraph B(2), accomplish the following in accordance with the inspection procedures set forth in Cessna Service Letter SL56-2, dated November 9, 1973, or FAA-approved revisions or any equivalent method approved by the Chief, Engineering and Manufacturing Branch, FAA, Central Region: A) Either by use of x-ray procedures outlined in Cessna Service Letter SL56-2, dated November 9, 1973, inspect the flight compartment side windows (P/Ns 5511265-3 and -4) at the attachment locations, or in the alternative, visually inspect the window attachment locations by first removing the window outside retainers in accordance with the manufacturer's service instructions. B) (1) Prior to further pressurized flight replace unairworthy windows if as a result of any inspection required by this AD any of the following conditions are found: (a) A crack is visible in the window pane which has progressed past the edge of the retainer. (b) Any three or more screw holes are interconnected by a crack. (c) A crack has progressed to three inches or longer. (d) The sum of individual crack lengths exceeds six inches. (2) If a crack is discovered in a window pane but does not exceed any of the conditions specified in Paragraph B(1), inspect the window panes each 100 hours' time in service thereafter per Paragraph A of the AD until the window panes are replaced. C) Upon accumulation of 400 hours' time in service inspect replacement window panes in accordance with the requirements of this AD. D) The inspections and 400 hour window replacement requirements of this AD may be discontinued upon installation of left and right flight compartment side windows (P/N 5511285-3 and -4) in accordance with Cessna Service Bulletin SB 56-4 dated July 24, 1974, or later approved revisions. Any equivalent method must be approved by the Chief, Engineering and Manufacturing Branch, FAA, Central Region. Amendment 39-1763 became effective December 26, 1973. This Amendment 39-1983 becomes effective October 9, 1974. FOOTER:
Document Text
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AD Final Rules - DRS_73-26-09.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 73-26-09 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; CESSNA Model 500 Airplanes Subject: Flight Compartment Side Windows Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 10/09/1974 Make: Cessna Aircraft Company Model: 500 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: 73-26-09 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-1983 AD NUMBER: 73-26-09 SUBJECT HEADING: Airworthiness Directives; CESSNA Model 500 Airplanes ACTION: SUMMARY: DATES: Effective October 9, 1974. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 73-26-09 CESSNA: Amendment 39-1763 as amended by Amendment 39-1983. Applies to Model 500 (Serial Numbers 500-0001 through 500-0183) airplanes, with 400 or more hours' time in service. Compliance: Required as indicated, unless already accomplished. To detect cracks in the left and right flight compartment side windows (P/Ns 5511265-3 and -4), within the next 25 hours' time in service after the effective date of this AD, (on all airplanes with 400 or more hours' time in service) and thereafter at intervals not to exceed 200 hours' time in service, except as provided in Paragraph B(2), accomplish the following in accordance with the inspection procedures set forth in Cessna Service Letter SL56-2, dated November 9, 1973, or FAA-approved revisions or any equivalent method approved by the Chief, Engineering and Manufacturing Branch, FAA, Central Region: A) Either by use of x-ray procedures outlined in Cessna Service Letter SL56-2, dated November 9, 1973, inspect the flight compartment side windows (P/Ns 5511265-3 and -4) at the attachment locations, or in the alternative, visually inspect the window attachment locations by first removing the window outside retainers in accordance with the manufacturer's service instructions. B) (1) Prior to further pressurized flight replace unairworthy windows if as a result of any inspection required by this AD any of the following conditions are found: (a) A crack is visible in the window pane which has progressed past the edge of the retainer. (b) Any three or more screw holes are interconnected by a crack. (c) A crack has progressed to three inches or longer. (d) The sum of individual crack lengths exceeds six inches. (2) If a crack is discovered in a window pane but does not exceed any of the conditions specified in Paragraph B(1), inspect the window panes each 100 hours' time in service thereafter per Paragraph A of the AD until the window panes are replaced. C) Upon accumulation of 400 hours' time in service inspect replacement window panes in accordance with the requirements of this AD. D) The inspections and 400 hour window replacement requirements of this AD may be discontinued upon installation of left and right flight compartment side windows (P/N 5511285-3 and -4) in accordance with Cessna Service Bulletin SB 56-4 dated July 24, 1974, or later approved revisions. Any equivalent method must be approved by the Chief, Engineering and Manufacturing Branch, FAA, Central Region. Amendment 39-1763 became effective December 26, 1973. This Amendment 39-1983 becomes effective October 9, 1974. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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