AD 91-16-01
final rule
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Mitsubishi Heavy Industries, Ltd. | YS-11 | Airworthiness Directives; MITSUBISHI Models YS-11, YS-11A-200, YS-11A-300, YS-11A-500, and YS-11A-600 Series Airplanes |
| aircraft | Mitsubishi Heavy Industries, Ltd. | YS-11A-200 | Airworthiness Directives; MITSUBISHI Models YS-11, YS-11A-200, YS-11A-300, YS-11A-500, and YS-11A-600 Series Airplanes |
| aircraft | Mitsubishi Heavy Industries, Ltd. | YS-11A-300 | Airworthiness Directives; MITSUBISHI Models YS-11, YS-11A-200, YS-11A-300, YS-11A-500, and YS-11A-600 Series Airplanes |
| aircraft | Mitsubishi Heavy Industries, Ltd. | YS-11A-500 | Airworthiness Directives; MITSUBISHI Models YS-11, YS-11A-200, YS-11A-300, YS-11A-500, and YS-11A-600 Series Airplanes |
| aircraft | Mitsubishi Heavy Industries, Ltd. | YS-11A-600 | Airworthiness Directives; MITSUBISHI Models YS-11, YS-11A-200, YS-11A-300, YS-11A-500, and YS-11A-600 Series Airplanes |
Unsafe Condition
Uncontrolled nose down pitch of the airplane on landing approach during icing conditions due to flap extension beyond 20 degrees in known icing conditions or visible moisture below +5°C (+41°F) OAT.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Revise the AFM's Operating Limitations Section to restrict flaps to 20 degrees in specified conditions, add a placard near the flap handle, insert specific MHI Transmittal Letters into the AFM, and revise the AFM's Normal Operating Procedures Section with cautionary notes.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within 30 days after March 19, 1991 for paragraph (a), and within 30 days after August 22, 1991 for paragraphs (b) through (e).
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Mitsubishi Heavy Industries, Ltd. Models YS-11, YS-11A-200, YS-11A-300, YS-11A-500, and YS-11A-600 series airplanes, certificated in any category.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Wing De-Icer System
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_91-16-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 91-16-01 Document Type: AD Final Rules Docket Number: 91-NM-118-AD Subject Heading: Airworthiness Directives; MITSUBISHI Models YS-11, YS-11A-200, YS-11A-300, YS-11A-500, and YS-11A-60...Show more Subject: Wing De-Icer System Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 08/22/1991 Make: Mitsubishi Heavy Industries, Ltd. Model: YS-11 | YS-11A-200 | YS-11A-300 | YS-11A-500 | YS-11A-600 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: 91-16-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: 91-NM-118-AD AMENDMENT: 39-7091 AD NUMBER: 91-16-01 SUBJECT HEADING: Airworthiness Directives; MITSUBISHI Models YS-11, YS-11A-200, YS-11A-300, YS-11A-500, and YS-11A-600 Series Airplanes ACTION: SUMMARY: DATES: Effective August 22, 1991. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 91-16-01 MITSUBISHI HEAVY INDUSTRIES (MHI), LTD. [formerly Nihon Aeroplane Manufacturing Company (NMAC)]: Amendment 39-7091. Docket No. 91-NM-118-AD. Supersedes AD 91-06-04. Applicability: Model YS-11, YS-11A-200, YS-11A-300, YS-11A-500, and YS-11A-600 series airplanes, certificated in any category. Compliance: Required as indicated, unless previously accomplished. To prevent uncontrolled nose down pitch of the airplane on landing approach during icing conditions, accomplish the following: (a) Within 30 days after March 19, 1991 (the effective date of Amendment 39-6922, AD 91- 06-04), accomplish the following: (1) Revise the Operating Limitations Section of the FAA-approved Airplane Flight Manual (AFM) for the Model YS-11/-11A by adding a subparagraph B. to paragraph 1.10.5, WING DE- ICER SYSTEM, to read as follows: This may be accomplished by inserting a copy of this AD in the AFM. "B. Do not extend flaps greater than 20 degrees in the presence of known icing conditions or in visible moisture below plus 5 degrees centigrade (plus 41 degrees Fahrenheit) outside air temperature (OAT)." (2) Add a placard as near as possible to the flap handle to read as follows: "Flaps limited to 20 degrees in known icing conditions." (b) Within 30 days after the effective date of this amendment, accomplish the following: (1) Insert the following MHI Transmittal Letters in the Normal Operating Procedures Section of the AFM, as applicable: (i) For Model YS-11 airplanes: NMAC YS-11 Flight Manual Publication No. YS-FM-001, Transmittal Letter E32, dated October 2, 1990; (ii) For Model YS-11A-200 and -300 series airplanes: NMAC YS-11A- 200/300 Flight Manual Publication No. YS-FM-002, Transmittal Letter No. E2027, dated October 2, 1990; (iii) For Model YS-11A-500 series airplanes: NMAC YS-11A-500 Flight Manual Publication No. YS-FM-005, Transmittal Letter No. E5021, dated October 2, 1990; (iv) For Model YS-11A-600 series airplanes: NMAC YS-11A-600 Flight Manual Publication No. YS-FM-006, Transmittal Letter No. E6021, dated October 2, 1990. (2) In the Normal Operating Procedures Section of the AFM, just after the MHI Transmittal Letter required by paragraph (b)(1) of this AD, revise subparagraph "(2) Flaps" of paragraph 3.1.10.1, APPROACH AND LANDING IN ICING CONDITIONS OR IN VISIBLE MOISTURE BELOW plus 5 DEGREES C (plus 41 DEGREES F) OAT, to read as follows: This may be accomplished by inserting a copy of this AD in the AFM. "(2) Flaps.............................................Set Position NOTE: Do not extend flaps greater than 20 degrees. CAUTION: IF UNUSUAL PITCHING OR YOKE MOVEMENT OCCURS WHILE EXTENDING THE FLAPS, IMMEDIATELY RETRACT THE FLAPS UNTIL THE PITCHING OR YOKE MOVEMENT STOPS." (c) 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, Los Angeles Aircraft Certification Office (ACO), 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, Los Angeles ACO. NOTE: Previous FAA approval granted for an alternative method of compliance with AD 91-06- 04 constitutes FAA approval as an alternative method of compliance with this AD. (d) 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. (e) The AFM revision requirements shall be accomplished, in part, by incorporating the following documents into the AFM: NMAC YS-11 Flight Manual Publication No. YS-FM-001, Transmittal Letter E32; NMAC YS-11A-200/300 Flight Manual Publication No. YS-FM-002, Transmittal Letter No. E2027; NMAC YS-11A-500 Flight Manual Publication No. YS-FM-005, Transmittal Letter No. E5021; NMAC YS-11A-600 Flight Manual Publication No. YS-FM-006, Transmittal Letter No. E6021; all of which are dated October 2, 1990. These documents contain the following list of effective pages: Publication Number/ Transmittal Letter Number Section Code Symbol Page Number Publication No. YS-FM-001 Transmittal Letter E32, dated October 2, 1990 Transmittal Sheet L.E.P. Log of Revision (1) 3 T/L E32 (none) (none) (none) (none) (none) 1/1 i ii-10 i 25 25a Publication No. YS-FM-002 Transmittal Letter E2027 dated October 2, 1990 Transmittal Sheet L.E.P. Log of Revision (1) 3 T/L E2027 E101 E101 E100 E100 E100 1/1 i ii-8 i 21 22 Publication No. YS-FM-005 Transmittal Letter E5021 dated October 2, 1990 Transmittal Sheet L.E.P. Log of Revision (1) 3 T/L E5021 E500 E156 E100 E100 E100 1/1 i ii-5 i 21 22 Publication No. YS-FM-006 Transmittal Letter E6021 dated October 2, 1990 Transmittal Sheet L.E.P. Log of Revision (1) 3 T/L E6021 E600 E156 E100 E100 E100 1/1 i ii-5 i 21 22 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 Nagoya Aircraft Works, Mitsubishi Heavy Industries, Ltd., 10 Oye-cho, Minato-Ku, Nagoya 455, Japan, Attention: Manager, YS-11 Group, Service Department. This information may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 1601 Lind Avenue S.W., Renton, Washington; or at the Los Angeles Aircraft Certification Office, 3229 East Spring Street, Long Beach, California; or at the Office of the Federal Register, 1100 L Street N.W., Room 8401, Washington, D.C. Airworthiness Directive 91-16-01 supersedes AD 91-06-04, Amendment 39-6922. This amendment (39-7091, AD 91-16-01) becomes effective on August 22, 1991. FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_91-16-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 91-16-01 Document Type: AD Final Rules Docket Number: 91-NM-118-AD Subject Heading: Airworthiness Directives; MITSUBISHI Models YS-11, YS-11A-200, YS-11A-300, YS-11A-500, and YS-11A-60...Show more Subject: Wing De-Icer System Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 08/22/1991 Make: Mitsubishi Heavy Industries, Ltd. Model: YS-11 | YS-11A-200 | YS-11A-300 | YS-11A-500 | YS-11A-600 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: 91-16-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: 91-NM-118-AD AMENDMENT: 39-7091 AD NUMBER: 91-16-01 SUBJECT HEADING: Airworthiness Directives; MITSUBISHI Models YS-11, YS-11A-200, YS-11A-300, YS-11A-500, and YS-11A-600 Series Airplanes ACTION: SUMMARY: DATES: Effective August 22, 1991. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 91-16-01 MITSUBISHI HEAVY INDUSTRIES (MHI), LTD. [formerly Nihon Aeroplane Manufacturing Company (NMAC)]: Amendment 39-7091. Docket No. 91-NM-118-AD. Supersedes AD 91-06-04. Applicability: Model YS-11, YS-11A-200, YS-11A-300, YS-11A-500, and YS-11A-600 series airplanes, certificated in any category. Compliance: Required as indicated, unless previously accomplished. To prevent uncontrolled nose down pitch of the airplane on landing approach during icing conditions, accomplish the following: (a) Within 30 days after March 19, 1991 (the effective date of Amendment 39-6922, AD 91- 06-04), accomplish the following: (1) Revise the Operating Limitations Section of the FAA-approved Airplane Flight Manual (AFM) for the Model YS-11/-11A by adding a subparagraph B. to paragraph 1.10.5, WING DE- ICER SYSTEM, to read as follows: This may be accomplished by inserting a copy of this AD in the AFM. "B. Do not extend flaps greater than 20 degrees in the presence of known icing conditions or in visible moisture below plus 5 degrees centigrade (plus 41 degrees Fahrenheit) outside air temperature (OAT)." (2) Add a placard as near as possible to the flap handle to read as follows: "Flaps limited to 20 degrees in known icing conditions." (b) Within 30 days after the effective date of this amendment, accomplish the following: (1) Insert the following MHI Transmittal Letters in the Normal Operating Procedures Section of the AFM, as applicable: (i) For Model YS-11 airplanes: NMAC YS-11 Flight Manual Publication No. YS-FM-001, Transmittal Letter E32, dated October 2, 1990; (ii) For Model YS-11A-200 and -300 series airplanes: NMAC YS-11A- 200/300 Flight Manual Publication No. YS-FM-002, Transmittal Letter No. E2027, dated October 2, 1990; (iii) For Model YS-11A-500 series airplanes: NMAC YS-11A-500 Flight Manual Publication No. YS-FM-005, Transmittal Letter No. E5021, dated October 2, 1990; (iv) For Model YS-11A-600 series airplanes: NMAC YS-11A-600 Flight Manual Publication No. YS-FM-006, Transmittal Letter No. E6021, dated October 2, 1990. (2) In the Normal Operating Procedures Section of the AFM, just after the MHI Transmittal Letter required by paragraph (b)(1) of this AD, revise subparagraph "(2) Flaps" of paragraph 3.1.10.1, APPROACH AND LANDING IN ICING CONDITIONS OR IN VISIBLE MOISTURE BELOW plus 5 DEGREES C (plus 41 DEGREES F) OAT, to read as follows: This may be accomplished by inserting a copy of this AD in the AFM. "(2) Flaps.............................................Set Position NOTE: Do not extend flaps greater than 20 degrees. CAUTION: IF UNUSUAL PITCHING OR YOKE MOVEMENT OCCURS WHILE EXTENDING THE FLAPS, IMMEDIATELY RETRACT THE FLAPS UNTIL THE PITCHING OR YOKE MOVEMENT STOPS." (c) 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, Los Angeles Aircraft Certification Office (ACO), 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, Los Angeles ACO. NOTE: Previous FAA approval granted for an alternative method of compliance with AD 91-06- 04 constitutes FAA approval as an alternative method of compliance with this AD. (d) 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. (e) The AFM revision requirements shall be accomplished, in part, by incorporating the following documents into the AFM: NMAC YS-11 Flight Manual Publication No. YS-FM-001, Transmittal Letter E32; NMAC YS-11A-200/300 Flight Manual Publication No. YS-FM-002, Transmittal Letter No. E2027; NMAC YS-11A-500 Flight Manual Publication No. YS-FM-005, Transmittal Letter No. E5021; NMAC YS-11A-600 Flight Manual Publication No. YS-FM-006, Transmittal Letter No. E6021; all of which are dated October 2, 1990. These documents contain the following list of effective pages: Publication Number/ Transmittal Letter Number Section Code Symbol Page Number Publication No. YS-FM-001 Transmittal Letter E32, dated October 2, 1990 Transmittal Sheet L.E.P. Log of Revision (1) 3 T/L E32 (none) (none) (none) (none) (none) 1/1 i ii-10 i 25 25a Publication No. YS-FM-002 Transmittal Letter E2027 dated October 2, 1990 Transmittal Sheet L.E.P. Log of Revision (1) 3 T/L E2027 E101 E101 E100 E100 E100 1/1 i ii-8 i 21 22 Publication No. YS-FM-005 Transmittal Letter E5021 dated October 2, 1990 Transmittal Sheet L.E.P. Log of Revision (1) 3 T/L E5021 E500 E156 E100 E100 E100 1/1 i ii-5 i 21 22 Publication No. YS-FM-006 Transmittal Letter E6021 dated October 2, 1990 Transmittal Sheet L.E.P. Log of Revision (1) 3 T/L E6021 E600 E156 E100 E100 E100 1/1 i ii-5 i 21 22 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 Nagoya Aircraft Works, Mitsubishi Heavy Industries, Ltd., 10 Oye-cho, Minato-Ku, Nagoya 455, Japan, Attention: Manager, YS-11 Group, Service Department. This information may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 1601 Lind Avenue S.W., Renton, Washington; or at the Los Angeles Aircraft Certification Office, 3229 East Spring Street, Long Beach, California; or at the Office of the Federal Register, 1100 L Street N.W., Room 8401, Washington, D.C. Airworthiness Directive 91-16-01 supersedes AD 91-06-04, Amendment 39-6922. This amendment (39-7091, AD 91-16-01) becomes effective on August 22, 1991. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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