AD 91-16-01 ACTIVE

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 ModelYS-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/LE6021
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.