[Federal Register Volume 63, Number 180 (Thursday, September 17, 1998)]
[Rules and Regulations]
[Pages 49661-49666]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-24905]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-236-AD; Amendment 39-10767; AD 98-20-01]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is applicable to certain Bombardier Model CL-600-2B19 (Regional Jet 
Series 100) series airplanes. This action requires revising the 
Airplane Flight Manual (AFM) to provide the flight crew with revised 
procedures for checking the flap system. This AD also requires revising 
the maintenance program to provide procedures for checking the flap 
system, and performing follow-on actions, if necessary. This amendment 
is prompted by issuance of mandatory continuing airworthiness 
information by a foreign civil airworthiness authority. The actions 
specified in this AD are intended to prevent an unannunciated failure 
of the flap system, which could result in a flap asymmetry, and 
consequent reduced controllability of the airplane.

DATES: Effective October 2, 1998.
    Comments for inclusion in the Rules Docket must be received on or 
before October 19, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-236-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056.
    Information pertaining to this amendment may be examined at the 
FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington; or at the FAA, Engine and Propeller Directorate, New York 
Aircraft Certification Office, 10 Fifth Street, Third Floor, Valley 
Stream, New York.

FOR FURTHER INFORMATION CONTACT: Anthony E. Gallo, Aerospace Engineer, 
Systems and Flight Test Branch, ANE-172, the FAA, Engine and Propeller 
Directorate, New York Aircraft Certification Office, 10 Fifth Street, 
Third Floor, Valley Stream, New York; telephone (516) 256-7510; fax 
(516) 568-2716.


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SUPPLEMENTARY INFORMATION: Transport Canada Aviation (TCA), which is 
the airworthiness authority for Canada, recently notified the FAA that 
an unsafe condition may exist on certain Bombardier Model CL-600-2B19 
(Regional Jet Series 100) series airplanes. TCA advises that a number 
of failures of the flap system resulted in a twisted outboard flap 
panel. These failures of the flap system were attributed to an internal 
fault within the Number 3 flap actuator (the inboard actuator on the 
outboard flap). One report indicated that a twisted flap was not 
detected prior to take-off, and another report indicated that a twisted 
flap occurred upon deployment of the flaps for landing. However, in 
both of these cases, the airplane was controllable and landed 
successfully.
    Such an internal fault within the Number 3 actuator, if not 
corrected, could cause an unannunciated failure of the flap system, 
which could result in a flap asymmetry, and consequent reduced 
controllability of the airplane. [An annunciated failure of the flap 
system is normally displayed on the engine indicating and crew alert 
system (EICAS)].
    TCA has issued Canadian airworthiness directive (AD) CF-98-14, 
dated July 6, 1998, in order to assure the continued airworthiness of 
these airplanes in Canada. That AD describes procedures for amending 
the Limitations, Normal Procedures, and Abnormal Procedures sections of 
the Airplane Flight Manual (AFM). That AD also describes maintenance 
procedures and includes two figures that provide information for the 
normal/abnormal outboard flap configuration in take-off position, and 
the outboard flap go/no-go criteria in take-off position.

Other Relevant Proposed Rule

    The FAA has previously issued notice of proposed rulemaking (NPRM) 
Rules Docket 98-NM-134-AD, applicable to certain Bombardier Model CL-
600-2B19 (Regional Jet Series 100) series airplanes, which was 
published in the Federal Register on June 8, 1998 (63 FR 31140). That 
action proposed to require repetitive inspections of the inboard and 
outboard flap actuators to measure the rotational freedom of the 
actuator ball screw adjacent to the actuator housing, and replacement 
of the flap actuators with new or serviceable actuators, if necessary.

FAA's Determination/Interim Action

    The FAA has determined that the actions proposed by the NPRM 
described previously are inadequate to preclude an unannunciated 
failure of the flap system, which could result in a flap asymmetry, and 
consequent reduced controllability of the airplane. Therefore, in light 
of the reports described previously, the FAA has determined that the 
actions required by this AD are necessary to provide interim action to 
prevent an unannunciated failure of the flap system until final action 
is identified, at which time the FAA may consider further rulemaking.

FAA's Conclusions

    This airplane model is manufactured in Canada and is type 
certificated for operation in the United States under the provisions of 
section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and 
the applicable bilateral airworthiness agreement. Pursuant to this 
bilateral airworthiness agreement, TCA has kept the FAA informed of the 
situation described above. The FAA has examined the findings of TCA, 
reviewed all available information, and determined that AD action is 
necessary for products of this type design that are certificated for 
operation in the United States.

Explanation of Requirements of Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other airplanes of the same type design registered 
in the United States, this AD is being issued to prevent an 
unannunciated failure of the flap system, which could result in a flap 
asymmetry, and consequent reduced controllability of the airplane. This 
AD requires revising the Limitations, Normal, and Abnormal Procedures 
sections of the FAA-approved AFM to provide the flight crew with 
revised procedures for checking the flap system. This action also 
requires revising the maintenance program to provide revised procedures 
for checking the flap system, and performing follow-on actions, if 
necessary.

Differences Between This AD and the Canadian Airworthiness 
Directive

    Operators should note the following differences between this AD and 
the Canadian airworthiness directive:
     This AD further clarifies the personnel who are 
responsible for certain actions for checking the flap system or 
performing maintenance.
     A note in the Canadian airworthiness directive specifies 
that an acceptable procedure for testing of the flap drive breakaway 
input torque is detailed in Bombardier Service Letter RJ-SL-002A. 
However, a note in paragraph (b) of this AD specifies that such a 
procedure is detailed in Aircraft Maintenance Manual Temporary Revision 
27-203, Task 27-53-00-750-802, dated July 17, 1998.
     A requirement has been added to paragraph (a)(3) of this 
AD to specify that any abnormal flap control event should be recorded 
in the Aircraft Maintenance Log Book.
     The view that is specified in NOTE 2. of the Appendix 
(Part 2) of the Canadian airworthiness directive for the outboard flap 
go/no-go criteria in take-off position has been further clarified in 
Figure 2 of this AD.

Determination of Rule's Effective Date

    Since a situation exists that requires the immediate adoption of 
this regulation, it is found that notice and opportunity for prior 
public comment hereon are impracticable, and that good cause exists for 
making this amendment effective in less than 30 days.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and, thus, was not preceded by 
notice and an opportunity for public comment, comments are invited on 
this rule. Interested persons are invited to comment on this rule by 
submitting such written data, views, or arguments as they may desire. 
Communications shall identify the Rules Docket number and be submitted 
in triplicate to the address specified under the caption ADDRESSES. All 
communications received on or before the closing date for comments will 
be considered, and this rule may be amended in light of the comments 
received. Factual information that supports the commenter's ideas and 
suggestions is extremely helpful in evaluating the effectiveness of the 
AD action and determining whether additional rulemaking action would be 
needed.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the rule. All comments submitted will be 
available, both before and after the closing date for comments, in the 
Rules Docket for examination by interested persons. A report that 
summarizes each FAA-public contact concerned with the substance of this 
AD will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this rule must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 98-NM-236-AD.'' The postcard will be date stamped and 
returned to the commenter.

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Regulatory Impact

    The regulations adopted herein will not have substantial direct 
effects on the States, on the relationship between the national 
government and the States, or on the distribution of power and 
responsibilities among the various levels of government. Therefore, in 
accordance with Executive Order 12612, it is determined that this final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to correct an unsafe 
condition in aircraft, and that it is not a ``significant regulatory 
action'' under Executive Order 12866. It has been determined further 
that this action involves an emergency regulation under DOT Regulatory 
Policies and Procedures (44 FR 11034, February 26, 1979). If it is 
determined that this emergency regulation otherwise would be 
significant under DOT Regulatory Policies and Procedures, a final 
regulatory evaluation will be prepared and placed in the Rules Docket. 
A copy of it, if filed, may be obtained from the Rules Docket at the 
location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends part 39 of 
the Federal Aviation Regulations (14 CFR part 39) as follows:

PART 39--AIRWORTHINESS DIRECTIVES

    1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701.

Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

98-20-01  Bombardier, Inc.: Amendment 39-10767. Docket 98-NM-236-AD.

    Applicability: 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.

    Compliance: 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.''

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    (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]
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