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95-25-11 EMBRAER: Amendment 39-9457. Docket 95-NM-236-AD.
Applicability: All Model EMB-120 series airplanes, 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 use the authority provided in paragraph (e) of this AD to request approval from the FAA. This approval may address either no action, if the current configuration eliminates the unsafe condition; or different actions necessary to address the unsafe condition described in this AD. Such a request should include an assessment of the effect of the changed configuration on the unsafe condition addressed by this AD. In no case does the presence of any modification, alteration, or repair remove any airplane from the applicability of this AD.
Compliance: Required as indicated, unless accomplished previously.
To prevent failure of the propeller and subsequent reduced controllability of the airplane due to high stresses on the propeller at certain nominal propeller revolutions per minute (RPM), accomplish the following:
(a) Within 14 days after the effective date of this AD, accomplish the requirements of paragraphs (a)(1) and (a)(2) of this AD.
(1) Revise the Limitations Section (under "Propeller") of the FAA-approved Airplane Flight Manual (AFM) (in the basic AFM and in AFM Supplement 4) to include the following. This may be accomplished by inserting a copy of this AD in the AFM.
"Condition Levers must be in the MIN RPM position during all ground operations, except when cleared for takeoff or during landing roll.
"Power Levers must remain at or below Flight Idle during all ground operations, except for brief (approximately 5 seconds) excursions as needed to maneuver the airplane.
"CAUTION: Ground operation above Flight Idle significantly increases propeller stress under certain adverse wind conditions (e.g., tailwinds or rear crosswinds). Operation in this RPM range must be avoided to the maximum extent practicable."
(2) Revise the Normal Procedures Section (under "CLEARED INTO POSITION") of the FAA-approved AFM to separate the current procedures listed under the "CLEARED INTO POSITION" heading into two separate headings, as follows, to delay movement of condition levers until cleared for takeoff. This may be accomplished by inserting a copy of this AD into the AFM.
"CLEARED INTO POSITION
Landing Lights Switches ...................................................... ON
STROBE Light Switch ......................................................... ON
Transponder ....................................................................... ON
"CLEARED FOR TAKEOFF
Condition Levers ........................................................ MAX RPM
Multiple Alarm Panel Lights .................. CHECK EXTINGUISHED"
(b) Within 14 days after the effective date of this AD, remove the placard having part number (P/N) 120-30915-001 on the instrument panel of the cockpit.
(c) Within 30 days after the effective date of this AD, install a new placard having P/N 120- 61757-001 on the instrument panel of the cockpit.
(d) Within 14 days after the effective date of this AD, revise the FAA-approved maintenance program to incorporate the following into Chapter 61-00-00, "Propeller System Operating Limitations," and Chapter 71-00-00, "Propeller Operating Limitations," of the airplane maintenance manual:
"To prevent excessive propeller stress, do not operate above 60% Np UNLESS:
The wind is less than 10 knots, OR
The airplane is headed into the wind +/-45 degrees.
Wind direction must be monitored locally at the run up site."
(e) 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, Atlanta Aircraft Certification Office (ACO), FAA, Small 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, Atlanta ACO.
NOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Atlanta ACO.
(f) 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.
(g) This amendment becomes effective on December 27, 1995.
