AD 73-13-05
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Slingsby Aviation Ltd. | T.59.D Kestrel | Airworthiness Directives; SLINGSBY Model Glasflugel T.59.D "Kestrel" gliders. |
Unsafe Condition
Possible wing flutter due to aileron unbalance.
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Required Actions
Remove ailerons and measure balance hinge moment per Slingsby Technical Instructions No. 54. If hinge moment exceeds 8.5 lb.-ins average or 9.5 lb.-ins individually, install leading edge balance weights to limit each to ≤8.0 lb.-ins.
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Compliance Time
Within the next 10 hours' time in service after the effective date of this AD, and before further flight if corrective action is required.
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Affected Aircraft
Slingsby Aviation Ltd. Model T.59.D Kestrel gliders, excluding Glasflugel manufactured 'Kestrel' Model gliders.
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Federal Register Abstract
Aileron
Applicability Source Text
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AD Final Rules - DRS_73-13-05.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 73-13-05 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; SLINGSBY Model Glasflugel T.59.D "Kestrel" gliders. Subject: Aileron Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Slingsby Aviation Ltd. Model: T.59.D Kestrel Product Type: Aircraft Product Subtype: Glider Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 73-13-05 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-1672 AD NUMBER: 73-13-05 SUBJECT HEADING: Airworthiness Directives; SLINGSBY Model Glasflugel T.59.D "Kestrel" gliders. ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 73-13-05 SLINGSBY: Amdt. 39-1672. Applies to Model Glasflugel T.59.D "Kestrel" gliders. NOTE: This AD does not apply to Glasflugel manufactured "Kestrel" Model gliders. To prevent possible wing flutter due to aileron unbalance, accomplish the following, unless already accomplished: (a) Within the next 10 hours' time in service after the effective date of this AD, remove the ailerons from the glider and measure the aileron mass balance hinge Moment in accordance with Section 1 of Slingsby Sailplanes Technical Instructions No. 54, Issue 2, dated February 1973, or an FAA-approved equivalent. (b) If during the inspection required by paragraph (a), it is found that, either the average balance hinge moment of both ailerons exceeds 8.5 lb.-ins. or the balance hinge moment of either aileron exceeds 9.5 lb.-ins., before further flight, install balance weight on the leading edge of both ailerons in accordance with Section 2 of Slingsby Sailplane Technical Instructions No. 54, Issue 2, dated February 1973, or an FAA-approved equivalent such that the balance hinge moment of each aileron does not exceed 8.0 lb.-ins. This amendment is effective upon publication in the Federal Register as to all persons except those persons to whom it was made immediately effective upon receipt of the airmail letter dated May 21, 1973, which contained this amendment. FOOTER:
Document Text
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AD Final Rules - DRS_73-13-05.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 73-13-05 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; SLINGSBY Model Glasflugel T.59.D "Kestrel" gliders. Subject: Aileron Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Slingsby Aviation Ltd. Model: T.59.D Kestrel Product Type: Aircraft Product Subtype: Glider Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 73-13-05 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-1672 AD NUMBER: 73-13-05 SUBJECT HEADING: Airworthiness Directives; SLINGSBY Model Glasflugel T.59.D "Kestrel" gliders. ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 73-13-05 SLINGSBY: Amdt. 39-1672. Applies to Model Glasflugel T.59.D "Kestrel" gliders. NOTE: This AD does not apply to Glasflugel manufactured "Kestrel" Model gliders. To prevent possible wing flutter due to aileron unbalance, accomplish the following, unless already accomplished: (a) Within the next 10 hours' time in service after the effective date of this AD, remove the ailerons from the glider and measure the aileron mass balance hinge Moment in accordance with Section 1 of Slingsby Sailplanes Technical Instructions No. 54, Issue 2, dated February 1973, or an FAA-approved equivalent. (b) If during the inspection required by paragraph (a), it is found that, either the average balance hinge moment of both ailerons exceeds 8.5 lb.-ins. or the balance hinge moment of either aileron exceeds 9.5 lb.-ins., before further flight, install balance weight on the leading edge of both ailerons in accordance with Section 2 of Slingsby Sailplane Technical Instructions No. 54, Issue 2, dated February 1973, or an FAA-approved equivalent such that the balance hinge moment of each aileron does not exceed 8.0 lb.-ins. This amendment is effective upon publication in the Federal Register as to all persons except those persons to whom it was made immediately effective upon receipt of the airmail letter dated May 21, 1973, which contained this amendment. FOOTER:
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Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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