AD #: 2004-02-51
ATT: All owners and operators of all Empresa Brasileira de
Aeronautica S.A. (EMBRAER) Model EMB-135 and -145 series
The FAA has received a
report that the flightcrew of an EMBRAER Model EMB-135 series
airplane experienced rudder control difficulties during takeoff.
The airplane made an emergency landing; no injuries were reported.
Investigation revealed that the upper and lower control rods for
the aft rudder section had failed. (The rudder is composed of a
forward and an aft section.) The National Transportation Safety
Board is currently investigating the cause of the control rod
The airplane on which the incident occurred had accumulated
6,804 total flight hours and 6,371 total flight cycles. Although
the effect is unknown at this time, the airplane was operating
without Access Panel 312AR, as allowed by the Configuration
Deviation List (CDL). Failure of these control rods, if not
corrected, could result in loss of rudder control, or a possible
rudder jam. Also, an unrestrained aft rudder could enter a flutter
mode, which could result in loss of control of the airplane.
The rudder control rods on all EMBRAER Model EMB-135 and -145
series airplanes are identical to those on the affected Model
EMB-135 airplane. Therefore, all of these airplanes may be subject
to the same unsafe condition.
Explanation of Relevant
Service Information EMBRAER has issued Alert Service Bulletin
145-27-A105, dated January 23, 2004, which describes procedures
- A one-time visual inspection, including measurement, of the aft
rudder control rods to determine if they are assembled correctly
and to detect signs of structural damage, cracks, pitting, or
- If any discrepancy is found, replacement of the control rods
with new rods, accomplishment of a backlash test to determine the
condition of the rudder bearings, and accomplishment of any related
applicable corrective action. The service bulletin also recommends
that any airplane without Access Panel 312AR installed should have
the panel reinstalled.
The Departmento de Aviacao Civil (DAC), which is the
airworthiness authority for Brazil, classified this service
bulletin as mandatory and issued Brazilian emergency airworthiness
directive 2004-01-07, dated January 23, 2004, to ensure the
continued airworthiness of these airplanes in Brazil.
FAA's Conclusions: This airplane model is
manufactured in Brazil 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, the DAC has kept us informed of the
situation described above. We have examined the findings of the
DAC, 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 the Requirements of the Rule:
Since an unsafe condition has been identified that is likely to
exist or develop on other airplanes of this same type design
registered in the United States, this airworthiness directive is
issued to require accomplishment of the following actions per the
service bulletin described previously (except as discussed below
under the heading "Difference Between This AD and the Service
- A one-time general visual inspection of the aft rudder control
rods to detect any discrepancy (including, but not limited to,
incorrect installation, corrosion pitting, cracking, looseness,
deformity, or structural damage).
- If any discrepancy is found, replacement of the affected aft
rudder control rod with a new or serviceable control rod, and
accomplishment of a backlash test (to detect worn rudder bearings)
and any applicable corrective action.
This AD also requires the following actions, which are also
specified by the parallel Brazilian emergency airworthiness
- A general visual inspection to determine if Access Panel 312AR
is installed, and re-installing the panel.
- A revision to the CDL to remove reference to Access Panel 312AR
(thus prohibiting operation without that access panel
Difference Between This AD and the Service Bulletin:
Although the service
bulletin recommends that all inspection results, whether positive
or negative, be reported to the manufacturer, this AD requires
operators to submit a report to us only if a discrepancy is found.
Differences Between This AD and the Parallel Brazilian Emergency
Airworthiness Directive The Brazilian emergency airworthiness
directive specifies that, if any discrepancy is found, both control
rods must be replaced.
However, this AD requires that only discrepant control rods must
be replaced before further flight. We find that replacement of only
discrepant control rods will adequately address the unsafe
condition. Also, the Brazilian airworthiness directive specifies
that, if Access Panel 312AR is missing, this panel must be
installed before the next flight.
However, this AD requires that this panel must be installed
within 10 flight cycles after the inspection. In developing an
appropriate compliance time for this installation, we considered
the degree of urgency associated with the subject unsafe condition,
the average utilization of the affected fleet, and the availability
of necessary parts. In light of all of these factors, we find that
a 10-flight-cycle compliance time represents an appropriate
interval of time for affected airplanes to continue to operate
without compromising safety. We have coordinated these differences
with the DAC, and they concur.
Compliance: Required as indicated, unless
To detect and correct failure of the control rods for the aft
rudder, which could result in loss of control of the airplane,
accomplish the following:
One-Time Inspection and Configuration Deviation List
(a) Within 10 days or 100 flight cycles after the receipt of this
AD, whichever is first, accomplish paragraphs (a)(1), (a)(2), and
(a)(3) of this AD.
(1) Perform a general visual inspection of the aft rudder
control rods to detect any discrepancy (including, but not limited
to, incorrect installation, corrosion pitting, cracking,looseness,
deformity, or structural damage), and measure the dimension
the aft rudder control rods, per EMBRAER Alert Service Bulletin
145-27-A105, dated January 23, 2004.
(2) Perform a general visual inspection to determine if Access
Panel 312AR is installed on the airplane.
(3) Revise the Configuration Deviation List (CDL) to remove
Access Panel 312AR from the CDL (thus prohibiting operation without
that access panel installed). (This may be accomplished by
inserting a copy of this AD into the CDL.)
Note 2: For the purposes of this AD, a general visual inspection
is defined as: "A visual
examination of an interior or exterior area, installation,
oassembly to detect obvious damage, failure, or irregularity. This
level of inspection is made from within touching distance unless
otherwise specified. A mirror may be necessary to enhance visual
access to all exposed surfaces in the inspection area. This level
of inspection is made under normally available lighting conditions
such as daylight, hangar lighting, flashlight, or droplight and may
require removal or opening of access panels or doors. Stands,
ladders, or platforms may be required to gain proximity to the area
Effective Date: (g) AD 2004-02-51, issued on
January 23, 2004, becomes effective upon receipt.
FMI: www.faa.gov, Robert
Breneman, Manager, International
Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind
Avenue, SW., Renton,
Washington 98055-4056; telephone (425) 227-1263; fax (425)