AD 90-21-16

final rule

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

AD Number
90-21-16
Status
final_rule
Effective Date
Product Category
aircraft
Docket
90-NM-111-AD
FR Citation
This information is not available.

Applicability

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

Unsafe Condition

Loss of climb performance during single engine operation (i.e., one engine failed) and latent failures in the engine control unit.

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

Required Actions

Install modified electrical control units (ECU) in accordance with General Electric Service Bulletin 74-16 within 60 days after November 20, 1989. Remove any relays and associated wiring previously installed per SAAB-Scania Service Bulletins SAAB SF340-61-020 and SAAB SF340-77-003 within 60 days after the effective date of this amendment. Delete specific steps in the AFM's Emergency Procedures Section and Normal Procedures Expanded Checklist after completing the previous actions.

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

Compliance Time

Within 60 days after November 20, 1989 (for installing ECUs) and within 60 days after November 14, 1990 (for removing relays and wiring).

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 004 through 159, certified in any category.

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

Federal Register Abstract

Electrical Control Units

Applicability Source Text

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AD Number:
90-21-16
Document Type:
AD Final Rules
Docket Number:
90-NM-111-AD
Subject Heading:
Airworthiness Directives; SAAB-SCANIA Model SF-340A Series Airplanes
Subject:
Electrical Control Units
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
11/14/1990
Make:
Saab AB, Saab Aerosystems
Model:
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Superseded AD: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Superseded By: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: 90-21-16
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   90-NM-111-AD

AMENDMENT:   39-6763

AD NUMBER:   90-21-16

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

ACTION:   Final rule

SUMMARY:  

DATES:   Effective November 14, 1990.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
90-21-16 SAAB-SCANIA: Amendment 39-6763. Docket No. 90-NM-111-AD.
Applicability: Model SF-340A series airplanes, Serial Numbers 004 through 159, certified in any category.

Compliance: Required as indicated, unless previously accomplished.

To prevent loss of climb performance during single engine operation (i.e. one engine failed), and latent failures in the engine control unit, accomplish the following:

A. Within 60 days after November 20, 1989 (the effective date of Amendment 39-6361, AD 89- 22-08), install modified electrical control units (ECU) in accordance with General Electric Service Bulletin 74-16, dated March 22, 1989.

B. Within 60 days after the effective date of this amendment, remove any relays and associated wiring previously installed in accordance with SAAB-Scania Service Bulletins SAAB SF340- 61-020 and SAAB SF340-77-003, in accordance with the procedures specified in SAAB-SCANIA Service Bulletin SF340-77-006, dated March 9, 1990.

C. After completion of paragraphs A. and B. of this AD, delete steps referencing "Applicable With Mod. No. 1931" in the Emergency Procedures Section and Normal Procedures Expanded Checklist of the FAA-approved Airplane Flight Manual (AFM).

D. An alternate means 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 submitted directly to the Manager, Standardization Branch, ANM- 113, and a copy sent to the cognizant FAA Principal Inspector (PI). The PI will then forward comments or concurrence to the Manager, Standardization Branch, ANM-113.

E. 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, Aircraft Division, S.58188, 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 90-21-16 supersedes AD 89-22-08, Amendment 39- 6361.

This amendment (39-6763, AD 90-21-16) becomes effective on November 14, 1990.

FOOTER:

Document Text

Show stored source text (verify against official source)
AD Final Rules - DRS_90-21-16.html
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Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
90-21-16
Document Type:
AD Final Rules
Docket Number:
90-NM-111-AD
Subject Heading:
Airworthiness Directives; SAAB-SCANIA Model SF-340A Series Airplanes
Subject:
Electrical Control Units
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
11/14/1990
Make:
Saab AB, Saab Aerosystems
Model:
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: 90-21-16
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   90-NM-111-AD

AMENDMENT:   39-6763

AD NUMBER:   90-21-16

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

ACTION:   Final rule

SUMMARY:  

DATES:   Effective November 14, 1990.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
90-21-16 SAAB-SCANIA: Amendment 39-6763. Docket No. 90-NM-111-AD.
Applicability: Model SF-340A series airplanes, Serial Numbers 004 through 159, certified in any category.

Compliance: Required as indicated, unless previously accomplished.

To prevent loss of climb performance during single engine operation (i.e. one engine failed), and latent failures in the engine control unit, accomplish the following:

A. Within 60 days after November 20, 1989 (the effective date of Amendment 39-6361, AD 89- 22-08), install modified electrical control units (ECU) in accordance with General Electric Service Bulletin 74-16, dated March 22, 1989.

B. Within 60 days after the effective date of this amendment, remove any relays and associated wiring previously installed in accordance with SAAB-Scania Service Bulletins SAAB SF340- 61-020 and SAAB SF340-77-003, in accordance with the procedures specified in SAAB-SCANIA Service Bulletin SF340-77-006, dated March 9, 1990.

C. After completion of paragraphs A. and B. of this AD, delete steps referencing "Applicable With Mod. No. 1931" in the Emergency Procedures Section and Normal Procedures Expanded Checklist of the FAA-approved Airplane Flight Manual (AFM).

D. An alternate means 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 submitted directly to the Manager, Standardization Branch, ANM- 113, and a copy sent to the cognizant FAA Principal Inspector (PI). The PI will then forward comments or concurrence to the Manager, Standardization Branch, ANM-113.

E. 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, Aircraft Division, S.58188, 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 90-21-16 supersedes AD 89-22-08, Amendment 39- 6361.

This amendment (39-6763, AD 90-21-16) becomes effective on November 14, 1990.

FOOTER:

Source: Official FAA Source ↗

Retrieved: Apr 8, 2026

Rights: U.S. Government Public Domain

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