AD 98-01-03

final rule

Airworthiness Directives; Fokker Model F27 Mark 050 Series Airplanes

AD Number
98-01-03
Status
final_rule
Effective Date
Product Category
aircraft
Docket
97-NM-255-AD
FR Citation
Federal Register: December 31, 1997 (Volume 62, Number 250)

Applicability

TypeManufacturerModelDetails
aircraft Fokker Services F27 Mark 050 Airworthiness Directives; Fokker Model F27 Mark 050 Series Airplanes

Unsafe Condition

Accumulation of ice in the engine air intake duct leading to ice ingestion into the engine, which could result in engine power fluctuations and reduced controllability of the airplane.

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

Required Actions

Modify the air outlet opening of the engine air bypass duct in the left and right bottom engine cowling in accordance with Fokker Service Bulletin SBF50-71-041. An alternative method of compliance may be used if approved by the FAA.

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

Compliance Time

Within 3 months after the effective date of this AD (January 15, 1998).

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

Affected Aircraft

Fokker Model F27 Mark 050 series airplanes, serial numbers 20103 through 20296 inclusive, 20304, 20305, 20308, and 20311.

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

Federal Register Abstract

Air Oulet Opening Of Engine Air Bypass Duct

Applicability Source Text

Show captured applicability text from the source AD
AD Final Rules - DRS_98-01-03.html
Copy URL
Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
98-01-03
Document Type:
AD Final Rules
Docket Number:
97-NM-255-AD
Subject Heading:
Airworthiness Directives; Fokker Model F27 Mark 050 Series Airplanes
Subject:
Air Oulet Opening Of Engine Air Bypass Duct
Status:
Current
Citation:
Federal Register: December 31, 1997 (Volume 62, Number 250)
Citation Publish Date:
12/31/1997
Effective Date:
01/15/1998
Make:
Fokker Services
Model:
F27 Mark 050
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Superseded AD: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Superseded By: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 [62 FR 68159 NO. 250 12/31/97]
Comments:
AIRWORTHINESS DIRECTIVES FINAL RULES: 98-01-03
CITATION:   [Federal Register: December 31, 1997 (Volume 62, Number 250)]

PAGE NUMBER:   [Page 68159]

DOCKET NUMBER:   97-NM-255-AD

AMENDMENT:   39-10267

AD NUMBER:   98-01-03

SUBJECT HEADING:   Airworthiness Directives; Fokker Model F27 Mark 050 Series Airplanes

ACTION:   Final rule; request for comments

SUMMARY:   This amendment adopts a new airworthiness directive (AD), applicable to certain Fokker Model F27 Mark 050 series airplanes. This action requires modification of the air outlet opening of the engine air bypass duct. This amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified in this AD are intended to prevent accumulation of ice in the engine air intake duct and subsequent ingestion of ice into the engine, which could result in engine power fluctuations and reduced controllability of the airplane.

DATES:   Effective January 15, 1998. The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of January 15, 1998. Comments for inclusion in the Rules Docket must be received on or before January 30, 1998.

ADDRESSES:   Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 97-NM-255-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.
The service information referenced in this AD may be obtained from Fokker Services B.V., Technical Support Department, P.O. Box 75047, 1117 ZN Schiphol Airport, the Netherlands. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT:   International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-2110; fax (425) 227-1149.

SUPPLEMENTARY INFORMATION:  
The Rijksluchtvaartdienst (RLD), which is the airworthiness authority for the Netherlands, notified the FAA that an unsafe condition may exist on certain Fokker Model F27 Mark 050 series airplanes. The RLD advises that it has received a report indicating that, during icing conditions, power fluctuations occurred on both engines of an airplane. The airplane had been modified previously in accordance with four service bulletins to improve heating of the engine air intake duct and to counteract the effects of electromagnetic interference on the engine anti-icing systems; these modifications also were introduced in order to prevent power fluctuations caused by ingestion of ice into the engines. However, service experience has shown that, in certain weather conditions, accumulation of ice in the engine air intake duct can still occur, allowing ingestion of ice into the engine. This condition, if not corrected, could result in engine power fluctuations and reduced controllability of the airplane.

Explanation of Relevant Service Information
Fokker has issued Service Bulletin SBF50-71-041, dated November 10, 1993, which describes procedures for modification of the air outlet opening of the engine air bypass duct. The modification entails installing new parts in the engine bottom cowling to enlarge the outlet opening. Accomplishment of the actions specified in the service bulletin is intended to adequately address the unsafe condition. The RLD classified this service bulletin as mandatory and issued Dutch airworthiness directive BLA 1995-065 (A), dated June 30, 1995, in order to assure the continued airworthiness of these airplanes in the Netherlands.

FAA's Conclusions
This airplane model is manufactured in the Netherlands and is type certificated for operation in the United States under the provisions of section 21.29 of the Federal Aviation Regulations (14 CFR 21.19) and the applicable bilateral airworthiness agreement. Pursuant to this bilateral airworthiness agreement, the RLD has kept the FAA informed of the situation described above. The FAA has examined the findings of the RLD, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States.

Explanation of Requirements of the Rule
Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design registered in the United States, the proposed AD would require accomplishment of the actions specified in the service bulletin described previously.

Cost Impact
None of the Model F27 Mark 050 series airplanes affected by this action are on the U.S. Register. All airplanes included in the applicability of this rule currently are operated by non-U.S. operators under foreign registry; therefore, they are not directly affected by this AD action. However, the FAA considers that this rule is necessary to ensure that the unsafe condition is addressed in the event that any of these subject airplanes are imported and placed on the U.S. Register in the future.

Should an affected airplane be imported and placed on the U.S. Register in the future, it would require approximately 7 work hours to accomplish the required actions, at an average labor rate of $60 per work hour. Required parts would cost approximately $2,200. Based on these figures, the cost impact of this AD would be $2,620 per airplane. Determination of Rule's Effective Date

Since this AD action does not affect any airplane that is currently on the U.S. register, it has no adverse economic impact and imposes no additional burden on any person. Therefore, prior notice and public procedures hereon are unnecessary and the amendment may be made effective in less than 30 days after publication in the Federal Register.

Comments Invited
Although this action is in the form of a final rule and was not preceded by notice and opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified under the caption "ADDRESSES." All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this rule must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket Number 97-NM-255-AD." The postcard will be date stamped and returned to the commenter.

Regulatory Impact
The regulations adopted herein will not have substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government. Therefore, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.

For the reasons discussed above, I certify that this action (1) is not a "significant regulatory action" under Executive Order 12866; (2) is not a "significant rule" under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES."

List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.

Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:

PART 39 - AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.

§ 39.13 [Amended]
2. Section 39.13 is amended by adding the following new airworthiness directive:

REGULATORY TEXT:  
98-01-03 FOKKER: Amendment 39-10267. Docket 97-NM-255-AD.
Applicability: Model F27 Mark 050 series airplanes, serial numbers 20103 through 20296 inclusive, 20304, 20305, 20308, and 20311; certificated in any category.

NOTE 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (b) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously.

To prevent accumulation of ice in the engine air intake duct and subsequent ingestion of ice into the engine, which could result in engine power fluctuations and reduced controllability of the airplane, accomplish the following:

(a) Within 3 months after the effective date of this AD, modify the air outlet opening of the engine air bypass duct in the left and right bottom engine cowling in accordance with Fokker Service Bulletin SBF50-71-041, dated November 10, 1993.

(b) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, International Branch, ANM-116.

NOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the International Branch, ANM-116.

(c) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished.

(d) The modification shall be done in accordance with Fokker Service Bulletin SBF50-71- 041, dated November 10, 1993. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Fokker Services B.V., Technical Support Department, P.O. Box 75047, 1117 ZN Schiphol Airport, the Netherlands. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

NOTE 3: The subject of this AD is addressed in Dutch airworthiness directive BLA 1995-065 (A), dated June 30, 1995.

(e) This amendment becomes effective on January 15, 1998.

FOOTER:

Document Text

Show stored source text (verify against official source)
AD Final Rules - DRS_98-01-03.html
Copy URL
Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
98-01-03
Document Type:
AD Final Rules
Docket Number:
97-NM-255-AD
Subject Heading:
Airworthiness Directives; Fokker Model F27 Mark 050 Series Airplanes
Subject:
Air Oulet Opening Of Engine Air Bypass Duct
Status:
Current
Citation:
Federal Register: December 31, 1997 (Volume 62, Number 250)
Citation Publish Date:
12/31/1997
Effective Date:
01/15/1998
Make:
Fokker Services
Model:
F27 Mark 050
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 [62 FR 68159 NO. 250 12/31/97]
Comments:
AIRWORTHINESS DIRECTIVES FINAL RULES: 98-01-03
CITATION:   [Federal Register: December 31, 1997 (Volume 62, Number 250)]

PAGE NUMBER:   [Page 68159]

DOCKET NUMBER:   97-NM-255-AD

AMENDMENT:   39-10267

AD NUMBER:   98-01-03

SUBJECT HEADING:   Airworthiness Directives; Fokker Model F27 Mark 050 Series Airplanes

ACTION:   Final rule; request for comments

SUMMARY:   This amendment adopts a new airworthiness directive (AD), applicable to certain Fokker Model F27 Mark 050 series airplanes. This action requires modification of the air outlet opening of the engine air bypass duct. This amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified in this AD are intended to prevent accumulation of ice in the engine air intake duct and subsequent ingestion of ice into the engine, which could result in engine power fluctuations and reduced controllability of the airplane.

DATES:   Effective January 15, 1998. The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of January 15, 1998. Comments for inclusion in the Rules Docket must be received on or before January 30, 1998.

ADDRESSES:   Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 97-NM-255-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.
The service information referenced in this AD may be obtained from Fokker Services B.V., Technical Support Department, P.O. Box 75047, 1117 ZN Schiphol Airport, the Netherlands. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT:   International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-2110; fax (425) 227-1149.

SUPPLEMENTARY INFORMATION:  
The Rijksluchtvaartdienst (RLD), which is the airworthiness authority for the Netherlands, notified the FAA that an unsafe condition may exist on certain Fokker Model F27 Mark 050 series airplanes. The RLD advises that it has received a report indicating that, during icing conditions, power fluctuations occurred on both engines of an airplane. The airplane had been modified previously in accordance with four service bulletins to improve heating of the engine air intake duct and to counteract the effects of electromagnetic interference on the engine anti-icing systems; these modifications also were introduced in order to prevent power fluctuations caused by ingestion of ice into the engines. However, service experience has shown that, in certain weather conditions, accumulation of ice in the engine air intake duct can still occur, allowing ingestion of ice into the engine. This condition, if not corrected, could result in engine power fluctuations and reduced controllability of the airplane.

Explanation of Relevant Service Information
Fokker has issued Service Bulletin SBF50-71-041, dated November 10, 1993, which describes procedures for modification of the air outlet opening of the engine air bypass duct. The modification entails installing new parts in the engine bottom cowling to enlarge the outlet opening. Accomplishment of the actions specified in the service bulletin is intended to adequately address the unsafe condition. The RLD classified this service bulletin as mandatory and issued Dutch airworthiness directive BLA 1995-065 (A), dated June 30, 1995, in order to assure the continued airworthiness of these airplanes in the Netherlands.

FAA's Conclusions
This airplane model is manufactured in the Netherlands and is type certificated for operation in the United States under the provisions of section 21.29 of the Federal Aviation Regulations (14 CFR 21.19) and the applicable bilateral airworthiness agreement. Pursuant to this bilateral airworthiness agreement, the RLD has kept the FAA informed of the situation described above. The FAA has examined the findings of the RLD, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States.

Explanation of Requirements of the Rule
Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design registered in the United States, the proposed AD would require accomplishment of the actions specified in the service bulletin described previously.

Cost Impact
None of the Model F27 Mark 050 series airplanes affected by this action are on the U.S. Register. All airplanes included in the applicability of this rule currently are operated by non-U.S. operators under foreign registry; therefore, they are not directly affected by this AD action. However, the FAA considers that this rule is necessary to ensure that the unsafe condition is addressed in the event that any of these subject airplanes are imported and placed on the U.S. Register in the future.

Should an affected airplane be imported and placed on the U.S. Register in the future, it would require approximately 7 work hours to accomplish the required actions, at an average labor rate of $60 per work hour. Required parts would cost approximately $2,200. Based on these figures, the cost impact of this AD would be $2,620 per airplane. Determination of Rule's Effective Date

Since this AD action does not affect any airplane that is currently on the U.S. register, it has no adverse economic impact and imposes no additional burden on any person. Therefore, prior notice and public procedures hereon are unnecessary and the amendment may be made effective in less than 30 days after publication in the Federal Register.

Comments Invited
Although this action is in the form of a final rule and was not preceded by notice and opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified under the caption "ADDRESSES." All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this rule must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket Number 97-NM-255-AD." The postcard will be date stamped and returned to the commenter.

Regulatory Impact
The regulations adopted herein will not have substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government. Therefore, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.

For the reasons discussed above, I certify that this action (1) is not a "significant regulatory action" under Executive Order 12866; (2) is not a "significant rule" under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES."

List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.

Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:

PART 39 - AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.

§ 39.13 [Amended]
2. Section 39.13 is amended by adding the following new airworthiness directive:

REGULATORY TEXT:  
98-01-03 FOKKER: Amendment 39-10267. Docket 97-NM-255-AD.
Applicability: Model F27 Mark 050 series airplanes, serial numbers 20103 through 20296 inclusive, 20304, 20305, 20308, and 20311; certificated in any category.

NOTE 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (b) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously.

To prevent accumulation of ice in the engine air intake duct and subsequent ingestion of ice into the engine, which could result in engine power fluctuations and reduced controllability of the airplane, accomplish the following:

(a) Within 3 months after the effective date of this AD, modify the air outlet opening of the engine air bypass duct in the left and right bottom engine cowling in accordance with Fokker Service Bulletin SBF50-71-041, dated November 10, 1993.

(b) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, International Branch, ANM-116.

NOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the International Branch, ANM-116.

(c) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished.

(d) The modification shall be done in accordance with Fokker Service Bulletin SBF50-71- 041, dated November 10, 1993. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Fokker Services B.V., Technical Support Department, P.O. Box 75047, 1117 ZN Schiphol Airport, the Netherlands. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

NOTE 3: The subject of this AD is addressed in Dutch airworthiness directive BLA 1995-065 (A), dated June 30, 1995.

(e) This amendment becomes effective on January 15, 1998.

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.