AD 91-14-02

final rule

Airworthiness Directives; SAAB-SCANIA Model SF-340A and SAAB 340B Series Airplanes

AD Number
91-14-02
Status
final_rule
Effective Date
Product Category
aircraft
Docket
91-NM-28-AD
FR Citation
This information is not available.
Technical illustration of an aircraft flight control surface and actuator
Problem area Flight controls

Applicability

TypeManufacturerModelDetails
aircraft Saab AB, Saab Aerosystems SAAB 340B Airworthiness Directives; SAAB-SCANIA Model SF-340A and SAAB 340B Series Airplanes
aircraft Saab AB, Saab Aerosystems 340A (SAAB SF340A) Airworthiness Directives; SAAB-SCANIA Model SF-340A and SAAB 340B Series Airplanes

Unsafe Condition

Cracking in the vertical stabilizer top closure rib could cause inhibited airplane rudder control.

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

Required Actions

Inspect the vertical stabilizer top closure rib for cracking in accordance with SAAB Service Bulletin 340-55-022, Revision 1. If no cracking is found, reinspect at intervals not exceeding 500 flight hours. If cracking is found, stop drill the cracks, blend, clean, apply aluminum tape as specified, and reinspect at intervals not exceeding 100 hours. Replace the rib with a new thicker rib or reinforce and replace the attachment angle per SAAB Service Bulletin 340-55-023 within one year after this amendment's effective date.

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

Compliance Time

Prior to the accumulation of 500 hours time-in-service since new or within 100 hours time-in-service after August 30, 1990 (the effective date of Amendment 39-6676, AD 90-16-02), whichever occurs later. Additionally, within one year after the effective date of this amendment for the replacement or reinforcement requirement.

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

Affected Aircraft

SAAB-SCANIA Model SF-340A series airplanes, Serial Numbers 031 through 159; and SAAB 340B series airplanes, Serial Numbers 160 through 186.

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

Federal Register Abstract

Inspect Vertical Stabilizer

Applicability Source Text

Show captured applicability text from the source AD
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AD Number:
91-14-02
Document Type:
AD Final Rules
Docket Number:
91-NM-28-AD
Subject Heading:
Airworthiness Directives; SAAB-SCANIA Model SF-340A and SAAB 340B Series Airplanes
Subject:
Inspect Vertical Stabilizer
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
07/29/1991
Make:
Saab AB, Saab Aerosystems
Model:
SAAB 340B | 340A (SAAB SF340A)
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: 91-14-02
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   91-NM-28-AD

AMENDMENT:   39-7044

AD NUMBER:   91-14-02

SUBJECT HEADING:   Airworthiness Directives; SAAB-SCANIA Model SF-340A and SAAB 340B Series Airplanes

ACTION:   Final rule

SUMMARY:  

DATES:   Effective July 29, 1991.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
91-14-02 SAAB-SCANIA: Amendment 39-7044. Docket No. 91-NM-28-AD. Supersedes AD 90-16-02.
Applicability: Model SF-340A series airplanes, Serial Numbers 031 through 159; and SAAB 340B series airplanes, Serial Numbers 160 through 186; certificated in any category.

Compliance: Required as indicated, unless previously accomplished.

To prevent inhibited airplane rudder control due to cracking in the vertical stabilizer top closure rib, accomplish the following:

A. Prior to the accumulation of 500 hours time-in-service since new or within 100 hours time- in-service after August 30, 1990 (the effective date of Amendment 39-6676, AD 90-16-02), whichever occurs later, inspect the vertical stabilizer top closure rib for evidence of cracking, in accordance with SAAB Service Bulletin 340-55-022, Revision 1, dated February 27, 1990.

B. If no evidence of cracking is found, reinspect the vertical stabilizer top closure rib for cracking at intervals not to exceed 500 flight hours time-in-service.

C. If cracking is found, prior to further flight, stop drill the ends of the cracks, blend, clean, and apply aluminum tape, as specified in SAAB Service Bulletin 340-55-022, Revision 1, dated February 27, 1990. Reinspect for additional cracking and the condition of the aluminum tape at intervals not to exceed 100 hours time-in-service.

D. Within one year after the effective date of this amendment, either replace the rib with a new thicker rib with a larger radius, or reinforce the rib and replace the attachment angle, in accordance with SAAB Service Bulletin 340-55-023, dated October 1, 1990. Accomplishment of either of these modifications constitutes terminating action for repetitive inspections required by paragraphs B. and C. of this AD.

E. An alternative method of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, Standardization Branch, ANM- 113, FAA, Transport Airplane Directorate.

NOTE: The request should be forwarded through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Standardization Branch, ANM-113.

F. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base in order to comply with the requirements of this AD.

All persons affected by this directive who have not already received the appropriate service documents from the manufacturer may obtain copies upon request to SAAB-Scania AB, Product Support, S-581.88, Linkoping, Sweden. These documents may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 1601 Lind Avenue S.W., Renton, Washington.

Airworthiness Directive 39-7044 supersedes AD 90-16-02, Amendment 39-6676 which superseded AD 88-13-10, Amendment 39-5963.

This amendment (39-7044, AD 91-14-02) becomes effective on July 29, 1991.

FOOTER:

Document Text

Show stored source text (verify against official source)
AD Final Rules - DRS_91-14-02.html
Copy URL
Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
91-14-02
Document Type:
AD Final Rules
Docket Number:
91-NM-28-AD
Subject Heading:
Airworthiness Directives; SAAB-SCANIA Model SF-340A and SAAB 340B Series Airplanes
Subject:
Inspect Vertical Stabilizer
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
07/29/1991
Make:
Saab AB, Saab Aerosystems
Model:
SAAB 340B | 340A (SAAB SF340A)
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: 91-14-02
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   91-NM-28-AD

AMENDMENT:   39-7044

AD NUMBER:   91-14-02

SUBJECT HEADING:   Airworthiness Directives; SAAB-SCANIA Model SF-340A and SAAB 340B Series Airplanes

ACTION:   Final rule

SUMMARY:  

DATES:   Effective July 29, 1991.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
91-14-02 SAAB-SCANIA: Amendment 39-7044. Docket No. 91-NM-28-AD. Supersedes AD 90-16-02.
Applicability: Model SF-340A series airplanes, Serial Numbers 031 through 159; and SAAB 340B series airplanes, Serial Numbers 160 through 186; certificated in any category.

Compliance: Required as indicated, unless previously accomplished.

To prevent inhibited airplane rudder control due to cracking in the vertical stabilizer top closure rib, accomplish the following:

A. Prior to the accumulation of 500 hours time-in-service since new or within 100 hours time- in-service after August 30, 1990 (the effective date of Amendment 39-6676, AD 90-16-02), whichever occurs later, inspect the vertical stabilizer top closure rib for evidence of cracking, in accordance with SAAB Service Bulletin 340-55-022, Revision 1, dated February 27, 1990.

B. If no evidence of cracking is found, reinspect the vertical stabilizer top closure rib for cracking at intervals not to exceed 500 flight hours time-in-service.

C. If cracking is found, prior to further flight, stop drill the ends of the cracks, blend, clean, and apply aluminum tape, as specified in SAAB Service Bulletin 340-55-022, Revision 1, dated February 27, 1990. Reinspect for additional cracking and the condition of the aluminum tape at intervals not to exceed 100 hours time-in-service.

D. Within one year after the effective date of this amendment, either replace the rib with a new thicker rib with a larger radius, or reinforce the rib and replace the attachment angle, in accordance with SAAB Service Bulletin 340-55-023, dated October 1, 1990. Accomplishment of either of these modifications constitutes terminating action for repetitive inspections required by paragraphs B. and C. of this AD.

E. An alternative method of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, Standardization Branch, ANM- 113, FAA, Transport Airplane Directorate.

NOTE: The request should be forwarded through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Standardization Branch, ANM-113.

F. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base in order to comply with the requirements of this AD.

All persons affected by this directive who have not already received the appropriate service documents from the manufacturer may obtain copies upon request to SAAB-Scania AB, Product Support, S-581.88, Linkoping, Sweden. These documents may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 1601 Lind Avenue S.W., Renton, Washington.

Airworthiness Directive 39-7044 supersedes AD 90-16-02, Amendment 39-6676 which superseded AD 88-13-10, Amendment 39-5963.

This amendment (39-7044, AD 91-14-02) becomes effective on July 29, 1991.

FOOTER:

Source: Official FAA Source ↗

Retrieved: Apr 8, 2026

Rights: U.S. Government Public Domain

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