AD 97-26-06 Airworthiness Directives; Empresa Brasileira de Aeronautica, S.A. (EMBRAER) Model EMB-120 Series Airplanes

Models named: EMB-120 series. Read the applicability below — it usually turns on serial or part numbers too.

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 otherwise 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 (c) 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.

Required as indicated, unless accomplished previously. To ensure that the flightcrew is able to recognize the formation of significant ice accretion, which could result in reduced controllability of the airplane in normal icing conditions, accomplish the following: (a) Within 30 days after the effective date of this AD, accomplish paragraphs (a)(1) and (a)(2) of this AD. (1) Revise the Limitations Section of the FAA-approved Airplane Flight Manual (AFM) to include the following requirements for activation of the ice protection systems. This may be accomplished by inserting a copy of this AD in the AFM. ``TURN ON ICE PROTECTION SYSTEM and IGNITION SWITCHES AS FOLLOWS: AOA, TAT, SLIP, ENGINE AIR INLET, and IGNITION SWITCHES: --When atmospheric or ground icing conditions exist. PROPELLER: --When atmospheric or ground icing conditions exist, OR --At the first sign of ice formation anywhere on the aircraft. WING and TAIL LEADING EDGES, and WINDSHIELD: --At the first sign of ice formation anywhere on the aircraft. Note: On takeoff, delay activation of the wing and tail leading edge de-ice systems until reaching the final segment speed. Note: Atmospheric icing conditions exist when: --Indicated Outside Air Temperature (OAT) during ground operations or Total Air Temperature (TAT) in flight is 10 degrees C or below; and --Visible moisture in any form is present (such as clouds, fog with visibility of one mile or less, rain, snow, sleet, or ice crystals). Note: Ground icing conditions exist when: --Indicated OAT during ground operations is 10 degrees C or below; and --Surface snow, standing water, or slush is present on the ramps, taxiways, or runways. Note: For Operation in Atmospheric Icing Conditions: --Follow the procedures in the Normal Procedures Section under Operation in Icing Conditions.'' (2) Revise the Normal Procedures Section of the FAA-approved Airplane Flight Manual (AFM) to include the following additional and revised information regarding operation in icing conditions. This may be accomplished by inserting a copy of this AD in the AFM. ``Under DAILY CHECKS of the Ice Protection System, add the following: The following tests must be performed prior to the first flight of the day for which known or forecast icing conditions are anticipated. Ice Detector System TEST Button (if installed)....................PRESS Check normal test sequence. Under APPROACH Checklist, add the following: Minimum Airspeed.........APPROPRIATE TO FLAP POSITION (See Table Below) ------------------------------------------------------------------------ Gear/Flap Minimum Recommended Airspeed ------------------------------------------------------------------------ UP/0 deg.................................. 150 KIAS UP/15 deg................................. 130 KIAS ------------------------------------------------------------------------ Under OPERATION IN ICING CONDITIONS for FLYING INTO ICING CONDITION, replace the current AFM section information for normal icing conditions with the following: --During flight, monitoring for icing conditions should start whenever the indicated outside air temperature is near or below freezing or when operating into icing conditions, as specified in the Limitations Section of this manual. --When operating in icing conditions, the front windwhield corners (unheated areas), propeller spinners, and wing leading edges will provide good visual cues of ice accretion. --For airplanes equipped with an ice between system, icing conditions will also be indicated by the illumination of the ICE CONDITION light on the multiple alarm panel. --When atmospheric or ground icing conditions exist, proceed as follows: AOA, TAT, SLIP, and ENGINE AIR INLET.................................ON IGNITION Switches....................................................ON AIRSPEED (Flaps and Gear UP)...........................160 KIAS MINIMUM --When atmospheric or ground icing conditions exist, OR --At the first sing of ice formation any where on the aircraft, proceed as follows: PROPELLER Deicing Switch.............................................ON Select NORM mode if indicated OAT is above -10 deg. C (14 deg. F) or COLD mode if indicated OAT is below -10 deg. C (14 deg. F). --At the first sign of ice formation anywhere on the aircraft, proceed as follows: WINDSHIELD...........................................................ON WING and TAIL LEADING EDGE...........................................ON Visually evaluate the severity of the ice encounter and the rate of accretion and select light or heavy mode (1 minute or 3 minute cycle) based on this evaluation. Note: On takeoff, delay activation of the wing and tail leading edge de-ice systems until reaching the final segment speed. Note: The minimum NH required for proper operation of the pneumatic deicing system is 80%. At lower NH values, the pneumatic deicing system may not totally inflate, and the associated failure lights on the overhead panel may illuminate. If this occurs, increase NH. Holding configuration: Landing Gear Lever...................................................UP Flap Selector Lever..................................................UP N p ...............................................85% MINIMUM Increase N p as required to eliminate propeller vibrations. Approach and Landing procedure: Increase approach and landing speeds, according to the following flap settings, until landing is assured. Reduce airspeed to cross runway threshold (50 ft) at V REF. Flaps 15--Increase Speed by 10 KIAS (130+10) Flaps 25--Increase Speed by 10 KIAS (V REF25 +10) Flaps 45--Increase Speed by 5 KIAS (V REF45 +5) Go-Around procedure: Reduce values from Maximum Landing Weight Approach Climb Limited charts by: 1500 lbs. for PW 118 Engines 1544 lbs. for PW 118A and 118B Engines Flaps 15--Increase approach climb speed by 10 KIAS (V 2 +10); Decrease approach climb gradient by: 3.0% for PW 118 Engines 2.9% for PW 118A and 118B Engines Flaps 25--Increase landing climb speed by 10 KIAS (V REF25 +10) Flaps 45--Increase landing climb speed by 5 KIAS (V REF +5) CAUTION: The ice protection systems must be turned on immediately (except leading edge de-icers during takeoff) when the ICE CONDITION light illuminates on the multiple alarm panel or when any ice accretion is detected by visual observation or other cues. [[Page 66521]] CAUTION: Do not interrupt the automatic sequence of operation of the leading edge de-ice boots once it is turned ON. The system should be turned OFF only after leaving the icing conditions and after the protected surfaces of the wing are free of ice. (b) Within 10 months after the effective date of this AD, install an ice detector in accordance with EMBRAER Service Bulletin No.: 120-30-0027, dated May 9, 1997. (c) 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 ACO. Operators shall submit their requests through an appropriate FAA Principal Operations 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. (d) 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. (e) The installation of the ice detector shall be done in accordance with EMBRAER Service Bulletin No. 120-30-0027, dated May 9, 1997. 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 EMBRAER, Empresa Brasileira De Aeronautica S/A, Sao Jose Dos Campos, Brazil. 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. (f) This amendment becomes effective on January 23, 1998. Issued in Renton, Washington, on December 11, 1997. Gilbert L. Thompson, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 97-33000 Filed 12-18-97; 8:45 am] BILLING CODE 4910-13-U