AD 73-13-05

final rule

Airworthiness Directives; SLINGSBY Model Glasflugel T.59.D "Kestrel" gliders.

AD Number
73-13-05
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Unknown
FR Citation
This information is not available.
Technical illustration of an aircraft flight control surface and actuator
Problem area Flight controls

Applicability

TypeManufacturerModelDetails
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.

AI-generated summary from the source AD text. Verify against the official source before acting.

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.

AI-generated summary from the source AD text. Verify against the official source before acting.

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.

AI-generated summary from the source AD text. Verify against the official source before acting.

Affected Aircraft

Slingsby Aviation Ltd. Model T.59.D Kestrel gliders, excluding Glasflugel manufactured 'Kestrel' Model gliders.

AI-generated summary from the source AD text. Verify against the official source before acting.

Federal Register Abstract

Aileron

Applicability Source Text

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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Superseded AD: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Superseded By: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

Show stored source text (verify against official source)
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:

Source: Official FAA Source ↗

Retrieved: Apr 8, 2026

Rights: U.S. Government Public Domain

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