AD 59-16-01
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Twin Commander Aircraft LLC | 500 | Airworthiness Directives; Aero Commander Model 500, 520, 560, 560A, 560E, 680, 680E, 720 Aircraft |
| aircraft | Twin Commander Aircraft LLC | 520 | Airworthiness Directives; Aero Commander Model 500, 520, 560, 560A, 560E, 680, 680E, 720 Aircraft |
| aircraft | Twin Commander Aircraft LLC | 560 | Airworthiness Directives; Aero Commander Model 500, 520, 560, 560A, 560E, 680, 680E, 720 Aircraft |
| aircraft | Twin Commander Aircraft LLC | 560-A | Airworthiness Directives; Aero Commander Model 500, 520, 560, 560A, 560E, 680, 680E, 720 Aircraft |
| aircraft | Twin Commander Aircraft LLC | 560-E | Airworthiness Directives; Aero Commander Model 500, 520, 560, 560A, 560E, 680, 680E, 720 Aircraft |
| aircraft | Twin Commander Aircraft LLC | 680 | Airworthiness Directives; Aero Commander Model 500, 520, 560, 560A, 560E, 680, 680E, 720 Aircraft |
| aircraft | Twin Commander Aircraft LLC | 680-E | Airworthiness Directives; Aero Commander Model 500, 520, 560, 560A, 560E, 680, 680E, 720 Aircraft |
| aircraft | Twin Commander Aircraft LLC | 720 | Airworthiness Directives; Aero Commander Model 500, 520, 560, 560A, 560E, 680, 680E, 720 Aircraft |
Unsafe Condition
The possibility of a sump being formed between the fuel shut-off valve and the booster pump due to excessive line lengths creating water traps or low spots in the fuel line.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect fuel lines between the fuel shut-off valve and booster pumps. Clamp lines to existing structure for uniform slope. Replace 45-degree elbow with AN 822-8D 90-degree elbow if slope cannot be achieved. Shorten fuel lines or replace with new hoses if necessary.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
September 15, 1959
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Affected Aircraft
Twin Commander Aircraft LLC models 500, 520, 560, 560A, 560E, 680, 680E, 720, serial numbers 231 through 690.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Fuel Line Routing
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_59-16-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 59-16-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Aero Commander Model 500, 520, 560, 560A, 560E, 680, 680E, 720 Aircraft Subject: Fuel Line Routing Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Twin Commander Aircraft LLC Model: 500 | 520 | 560 | 560-A | 560-E | 680 | 680-E | 720 Product Type: Aircraft Product Subtype: Small Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: Updated RGL applicability to match AD applicability; CAR C-11-185 AIRWORTHINESS DIRECTIVES FINAL RULES: 59-16-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 59-16-01 SUBJECT HEADING: Airworthiness Directives; Aero Commander Model 500, 520, 560, 560A, 560E, 680, 680E, 720 Aircraft ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 59-16-01 AERO COMMANDER: Applies to All Models 500, 520, 560, 560A, 560E, 680, 680E, 720 Aircraft, Serial Numbers 231 Through 690. Compliance required not later than September 15, 1959. To improve fuel line routing and to eliminate the possibility of a sump being formed between the fuel shut-off valve and the booster pump, the following inspection and/or rework is necessary. (a) If inspection reveals excessive line lengths are creating water traps or low spots in the fuel line between the fuel shut-off valve and the fuel booster pumps, clamp the lines up to existing structure until a uniform slope is obtained. (b) If a uniform slope cannot be obtained by clamping up the line, remove the existing 45 degrees elbow at the shut-off valve and replace it with an AN 822-8D 90 degrees elbow. (c) If a uniform slope cannot be obtained after completing items (a) and (b), shorten fuel line until no low spots will exist upon reassembling and installation. (d) If existing hoses cannot be shortened, new hoses may be obtained from the manufacturer or Aero Commander distributor. See Aero Design Service Bulletin Number 54 for hose assembly part numbers and hose lengths. FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_59-16-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 59-16-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Aero Commander Model 500, 520, 560, 560A, 560E, 680, 680E, 720 Aircraft Subject: Fuel Line Routing Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Twin Commander Aircraft LLC Model: 500 | 520 | 560 | 560-A | 560-E | 680 | 680-E | 720 Product Type: Aircraft Product Subtype: Small Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: Updated RGL applicability to match AD applicability; CAR C-11-185 AIRWORTHINESS DIRECTIVES FINAL RULES: 59-16-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 59-16-01 SUBJECT HEADING: Airworthiness Directives; Aero Commander Model 500, 520, 560, 560A, 560E, 680, 680E, 720 Aircraft ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 59-16-01 AERO COMMANDER: Applies to All Models 500, 520, 560, 560A, 560E, 680, 680E, 720 Aircraft, Serial Numbers 231 Through 690. Compliance required not later than September 15, 1959. To improve fuel line routing and to eliminate the possibility of a sump being formed between the fuel shut-off valve and the booster pump, the following inspection and/or rework is necessary. (a) If inspection reveals excessive line lengths are creating water traps or low spots in the fuel line between the fuel shut-off valve and the fuel booster pumps, clamp the lines up to existing structure until a uniform slope is obtained. (b) If a uniform slope cannot be obtained by clamping up the line, remove the existing 45 degrees elbow at the shut-off valve and replace it with an AN 822-8D 90 degrees elbow. (c) If a uniform slope cannot be obtained after completing items (a) and (b), shorten fuel line until no low spots will exist upon reassembling and installation. (d) If existing hoses cannot be shortened, new hoses may be obtained from the manufacturer or Aero Commander distributor. See Aero Design Service Bulletin Number 54 for hose assembly part numbers and hose lengths. 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.
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