AD 98-20-01 Airworthiness Directives; Bombardier Model CL-600-2B19 (Regional Jet Series 100) Series Airplanes

Model CL-600-2B19 (Regional Jet Series 100) series airplanes, serial numbers 7003 and subsequent; 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 (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 prevent an unannunciated failure of the flap system, which could result in a flap asymmetry, and consequent reduced controllability of the airplane, accomplish the following: Note 2: Bombardier Service Letter RJ-SL-27-002A, dated April 8, 1998, and Service Letter RJ-SL-27-037, dated July 2, 1998, may provide operators with additional information concerning the actions required by this AD. However, accomplishment of the procedures specified in these service letters should not be considered to be an acceptable method of compliance with the requirements of this AD. (a) Within 10 days after the effective date of this AD, accomplish the requirements of paragraphs (a)(1), (a)(2), and (a)(3) of this AD. (1) Revise the Limitations Section of the FAA-approved AFM to include the following procedures and Figures 1 and 2 of this AD. Air Operator Actions IMPORTANT: If the outboard flap position is outside the ``GO'' range, as shown in figure 2., further flight is prohibited until required maintenance actions have been accomplished. 1. Touch-and-go landings for the purposes of training must be accomplished using a flap setting of 20 degrees for the entire procedure. 2. (a) Take-off flaps must be set prior to departure, and (b) An external visual check must be accomplished to detect any twisting, skewing, or abnormal deformation of the flaps, using the information given in Figures 1 and 2. Note 1: If the outboard flap position is outside the ``GO'' range as shown in figure 2., further flight is prohibited until required maintenance actions have been accomplished. Note 2: This visual check must be accomplished either by a member of the flight crew or by maintenance personnel, and the results reported directly to the pilot-in-command prior to take-off. 3. If any additional change to the flap position is necessary, prior to take-off, accomplish the visual check specified by the preceding paragraph 2. (b). (2) Revise the Normal Procedures Section of the FAA-approved AFM to include the following procedures: To minimize a possible flap twist in flight when operating flaps, operate the flap selector sequentially, stopping at each setting (i.e., 0 degrees, 8 degrees if applicable, 20 degrees, 30 degrees, 45 degrees; or operate the flap selector in reverse order), and waiting for the flaps to reach each position before selecting the next setting. Monitor the control wheel for abnormal control wheel angles during each transition in flap position. Note: This procedure is not applicable during a go-around or during any emergency aircraft handling procedure where prompt flap retraction is required. In these cases, follow the applicable AFM procedures. (3) Revise the Abnormal Procedures Section of the FAA-approved AFM to include the following procedures: If abnormal aileron control wheel angles develop during flap operation with the autopilot on, or if the aircraft rolls without pilot input with the autopilot off (with or without a `FLAPS FAIL' caution message), perform the following actions: 1. If flaps are being extended, immediately return the flaps to the previously selected position (e.g., for flaps selected from 8 degrees to 20 degrees, re-select 8 degrees). 2. If flaps are being retracted, the flap selector should remain in the currently selected position (e.g., for flaps selected from 20 degrees to 8 degrees, leave selector at 8 degrees). 3. Do not attempt to operate the flaps any further. 4. If the flaps are engaged, disconnect the autopilot. Note: When disconnecting the autopilot, anticipate an out-of- trim situation and hold the aileron control wheel in its current position. 5. For landing, perform the ``Flaps Failure'' procedure for the following conditions: (a) If an abnormal aileron control wheel angle to the left develops, do not land if a crosswind from the left is greater than 20 knots. (b) If an abnormal aileron control wheel angle to the right develops, do not land if a crosswind from the right is greater than 20 knots. 6. After landing, do not attempt to retract the flaps. Record the event in the Aircraft Maintenance Log Book and notify the person responsible for maintenance.'' BILLING CODE 4910-13-U [[Page 49664]] [GRAPHIC] [TIFF OMITTED] TR17SE98.000 [[Page 49665]] [GRAPHIC] [TIFF OMITTED] TR17SE98.001 BILLING CODE 4910-13-C [[Page 49666]] (b) Within 10 days after the effective date of this AD, revise the FAA-approved maintenance program to include the following procedures and Figures 1 and 2 of this AD: Maintenance Procedure Whenever a `FLAPS FAIL' caution message occurs, carry out the following procedures after landing: Note: These procedures are to be accomplished by maintenance personnel only. 1. Check that there have been no other `FLAPS FAIL' caution messages reported within the previous 72 hours. If a previous message has been reported, prior to further flight, perform the actions required in the following Maintenance Action section. If no previous `FLAPS FAIL' caution message has been reported, continue with the following: 2. Carry out an external visual check of each outboard flap for evidence of twisting, skewing, or abnormal deformation. (Reference Figures 1 and 2.) 3. If there is no evidence of twisting, skewing, or abnormal deformation, proceed as follows: (a) Reset the flap system ONLY ONCE by cycling circuit breakers CB1-F4 and CB2-F4. (b) If the system does not reset (i.e., the `FLAPS FAIL' caution message is still posted), prior to further flight, perform the actions required in the following Maintenance Action section. (c) If the system resets, cycle the flaps to 45 degrees and back to 0 degrees. Continued flap operation for up to a maximum of 72 hours is then permitted as long as no additional `FLAPS FAIL' caution message is indicated. (d) If an additional `FLAPS FAIL' caution message occurs within the period of 72 hours, as specified above, prior to further flight, perform the actions required in the following Maintenance Action section. (e) Within 72 hours, even if no further `FLAPS FAIL' messages have been indicated, perform the actions required in the following Maintenance Action section. 4. If there is evidence of twisting, skewing, or abnormal deformation, PRIOR TO FURTHER FLIGHT, perform the actions required in the following Maintenance Action section. Maintenance Action Whenever the outboard flap position indicator is outside the ``GO'' range as shown in Figure 2, or whenever directed to do so by the Maintenance Procedure above, perform the following procedures: A. Interrogate the flap electronic control unit (FECU) per Fault Isolation Manual, Section 27-50-00, Flaps Fault Isolation,' and rectify as applicable. B. Visually check each flap for evidence of twisting, skewing, or abnormal deformation. 1. If there is no evidence of twisting, skewing, or abnormal deformation, manually isolate any jammed, disconnected, or dragging component; and rectify all discrepant conditions. 2. If there is evidence of twisting, skewing, or abnormal deformation, replace both actuators and any discrepant flap panel with new or serviceable components. In addition, inspect flexible shaft(s) inboard of the most outboard actuator removed for discrepancies, and replace any discrepant flexible shaft with a new or serviceable flexible shaft. Note: An acceptable procedure for testing the flap drive breakaway input torque is detailed in Aircraft Maintenance Manual Temporary Revision 27-203, Task 27-53-00-750-802, dated July 17, 1998. C. Within 3 days after identifying a flap panel twist or logging a `FLAPS FAIL' caution message, notify Bombardier Aerospace, via the Canadair Regional Jet Action Center, of all findings and actions taken.'' (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, New York Aircraft Certification Office (ACO), FAA, Engine and Propeller Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector or FAA Principal Operations Inspector, who may add comments and then send it to the Manager, New York ACO. Note 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the New York 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. Note 4: The subject of this AD is addressed in Canadian airworthiness directive CF-98-14, dated July 6, 1998. (e) This amendment becomes effective on October 2, 1998. Issued in Renton, Washington, on September 11, 1998. Dorenda D. Baker, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 98-24905 Filed 9-16-98; 8:45 am] BILLING CODE 4910-13-U