operator e-jets news rel 12

Issue No. 12 – November 2007

Issue No. 12 November 2007

Page 1

From the Editor

E-JETS NEWS is a publication that presents EMBRAER 170/190 aircraft technical items. This newsletter, compiled by EMBRAER Fleet Technical Center (EFTC), brings the latest developments and shares in-service knowledge and maintenance best practices. It also provides troubleshooting tips to optimize aircraft utilization and efficiency in daily operation.

E-JETS NEWS addresses Operators concerns with maintenance support and dispatchability of EMBRAER 170/190 aircraft. It has relevant information to be shared with the technical departments, such as Engineering and Maintenance. Recipients are encouraged to distribute this newsletter to EMBRAER Customers.

Earlier editions of E-JETS NEWS publication can be found at CIS / Aerochain at

http://www.aerochain.com

- Login (enter username and password);

- Select “Technical Services” and then “EMBRAER Customer Services”;

- Select “Maintenance Support”;

- Select “E-JETS NEWS;

- Click on desired E-JETS NEWS.

If any additional information regarding the in-service items covered in the E-JETS NEWS is needed, please contact the local EMBRAER Field Service Representative. General questions or comments about the E-JETS NEWS publication can be addressed to:

E-JETS NEWS

Tel: +55 12 3927 7075

Fax: +55 12 3927 5996

E-mail: [email protected]

PROPRIETARY NOTICE

The articles published in E-JETS NEWS are for information only and are an EMBRAER S/A property. This newsletter must not be reproduced or distributed in whole or in part to a third party without EMBRAER’s written consent. Also, no article published should be considered authority-approved data, unless specifically stated.


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Engine-Driven Pump (EDP) -03 Removals – Update

Effectivity: EMBRAER 170 / 190

As previously informed in E-Jets NEWS release No. 7 and release No. 9, EMBRAER issued SBs 170-29-0011 and 190-29-0007 on October 2006 replacing the current EDP with a new one 51164-03 in order to reduce the occurrences of external leakage and increase the reliability of the pump. The retrofit campaign is ongoing and around 90% of the fleet has part number -03.

As shown in the graph below, 25% of the returned pumps to Parker presented split line seal damage. The large face seal was found damaged, resulting in external leakage.

EDP -03 returns by failure mode(56 units - nov/07)

Split line seal

damage25

45%

Mod to -046

11%Other issues

814%

NFF17

30%

Face sealFace seal

The investigation about the split line seal is ongoing and both, EMBRAER and Parker, are working on a sampling plan with a specific operator. Units will run on-condition in an attempt to replicate the failure.

EDP evolution:

EDP 51164-04 has an improved design for the sealing of the front housing split line and port cap interface. It has an inner wall that isolates the seal from pressure fluctuations.

• PN 51164, PN 51164-01, and PN 51164-02 can be retrofitted directly to PN 51164-04 through SBs 170-29-0018 and 190-29-0014, FOC on a rotation basis. These SBs superseded SBs 170-29-0011 and 190-29-0007, respectively.

• PN 51164-03 can be retrofitted to PN 51164-04 on attrition basis, through SBs 170-29-0019 and 190-29-0015.

Pack Air Cycle Machine (ACM) Contamination – Update


As an update of E-Jets NEWS No. 8, EMBRAER informs that recently two RH contaminated heat exchangers, which were removed from revenue service operation, presented high flow restriction exceeding the specified delta-p limits.

Both heat exchangers presented clear evidence of contamination from beverages disposed of in the forward galley sink. The heat exchangers were removed for sampling purposes and also to help in the validation of an on-wing cleaning procedure.

EMBRAER and Hamilton Sundstrand are still analyzing those units to confirm the source and nature of this contamination in order to determine if this degradation on the exchanger performance was caused exclusively by the liquids disposed of in the forward galley sink. Such disposal is not recommended as per SNL 170-25-0004 / 190-25-0007.

It is important to highlight that a high delta-p on the heat exchanger may contribute to an ACM surge and its consequent failure.


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“N2 Fuel Pump Out of Range” CMC message – Update

Effectivity: EMBRAER 170

As posted in E-Jets NEWS release No. 9, EMBRAER has received reports about the occurrences of ENGINE SHORT DISPATCH on the EICAS with the correlated “N2 FUEL PUMP OUT OF RANGE” CMC message (fault code 73216417). Note: OVSP TEST FAULT CMC message can also be triggered.

In most cases, as previously informed, the N2 pump sensor replacement was the final action. Therefore, based on events and removals, GE and EMBRAER have started an investigation on this sensor.

Also, the removed sensors were sent to the manufacturer and, after tests, no faults were identified in the components. Therefore, in order to reproduce the fault, a suspected sensor was installed in an engine at GE for running test. However, the fault could not be reproduced.

Further tests have also been carried out in a specific bench test (with a variable gap) in order to measure the gap of the sensor, but the test was not successful in duplicating the fault. The next step of the investigation will be a destructive evaluation of the sensor. As soon as an update is available, EMBRAER and GE will inform.

Control Column Light Vibration with AP Engaged


EMBRAER has received some reports concerning occurrences of light vibration in the control column during flight, when the Auto Pilot is engaged and the Vertical Speed Mode is enabled. FOL 170-2007-066 was issued in Sept/2007 to inform about this event. FIM Tasks 22-11-00-810-91T-A, 22-11-00-810-91U-A, 22-11-00-810-91V-A, and 22-11-00-810-91W-A will be revised in order to provide troubleshooting instructions and will be available on the next FIM scheduled revision.

PSEM Hard Failure with Aircraft Weight off Wheels – Update


According to the information described in the E-Jets NEWS release No. 9 issued in August/ 2007, a minor change made to the Proximity Sensor Electronics Module (PSEM) resulted in an incompatibility between PSEM and MAU 1 Generic I/O 1 and MAU 3 Generic I/O 3. A specific number of PSEMs, Part Numbers 80-003-04 and 80-003-05, are affected by this modification.

The information presented herein is an update of the list of the affected components. The units already reworked at Liebherr-Aerospace have been removed from the list.

SERIAL NUMBER D294 E525 E756

SNLs 170-32-0023 and 190-32-0019 will be revised to include this information.

Mid/ Fwd E-bays Fans


EMBRAER is verifying an increase on Center/ Fwd Ebay Fans Fail events, based on maintenance reports from operators. Some of these cases were solved by cleaning the ebays flow sensors.

EMBRAER 170 AMS would like to emphasize the importance of following the cleaning procedure, subject of SNL 170-21-0014 (190-21-0007), to prevent such events.

Furthermore it is very important to return any relays K9, possibly removed during troubleshooting for Center/Fwd Ebay Fans Fail events, to the vendor (Hamilton Sundstrand). This would help EMBRAER/ HS to find the root causes for this relay failure, which is still under investigation.


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APU Oil Servicing


EMBRAER has tracked some reports of APU shutdowns that were fixed with oil servicing. Either oil under-servicing and over-servicing can cause an APU shutdown.

This scenario is commonly reported as an “APU auto shutdown”, without any correlated maintenance message. As the APU oil level is not electronically monitored, AMM Task 12-13-05-200-801-A should be performed every 700FH (IAW MRB Task 49-90-00-001) in order to prevent APU shutdowns.

In addition to that, EMBRAER recommends an opportunity APU oil level check before any APU troubleshooting procedure (i.e. upon access panel removal), as follows (Recommended APU pre-troubleshooting procedures):

1) Check CMC messages (do an APU FADEC NVM download for more detailed information).

2) Check the APU oil level.

3) Check for evidence of fuel/oil leaks.

4) Check all LRUs and electrical connectors for security.

5) Check the magnetic chip detector.

CMC Page Slow Navigation


After the installation of Primus EPIC 19.3/19.4, it has been identified that the CMC module processor may work under a heavy processing load when trying to overwrite old data on the Fault History Database (FHDB).

This may cause the CMC to respond slowly during operation. EMBRAER has released SNLs 170-45-0006 and 190-45-0006 providing an explanation and an interim solution for these CMC events, which will be available in the next AMM and FIM scheduled revisions.

Passenger Safety Card Revision


EMBRAER informs that the passenger safety cards of the EMBRAER 170/175 (which are usually located inside the passenger seat literature pockets) will be revised in order to reflect the clip/retainer installed in the PSU oxygen masks.

The purpose of the clip/retainer is to provide proper deployment of the oxygen masks of the PSU in case of cabin decompression.

The retainer must be removed from the masks in this situation; nevertheless, depending on the mask fall movement, the retainer may even become detached automatically.

The Flight Attendant Manual (FAM) – Standard Operation Procedures, section 3, already reflects this information through the flight attendant briefing. Please refer to FAM and SNL 170-25-0027 for further details. The picture below shows the illustration to be updated:

Pressurization System ACMF


A new ACMF application has recently been developed to support the investigation of pressurization system. EMBRAER technical representatives are encouraged to request the installation of this ACMF on aircraft from customers reporting cabin altitude inadvertent changes or any other reports related to passengers comfort being affected by pressurization system responses.

More information can be found on EFF (EMBRAER Fleet Forum) survey "Cabin Pressure Oscillation during cruise to descent transition". The ACMF file and all necessary documentation may be obtained from EMBRAER.


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REMOTE CB Trip Acknowledgement

Effectivity: EMBRAER 170 / 190 with SPDA BLOCK 10.2 and previous versions

EMBRAER has received some reports of REMOTE CB TRIP not being reset after its acknowledgement via MCDU. Further investigation has shown that this behavior was caused by duplicated parameters provided by the GCU to indicate a remote CB trip event.

More details regarding this issue are available in SNLs 170-24-0024 and 190-24-0018.

In case a Thermal Circuit Breaker of AICC, RICC, and LICC is not being acknowledged, a complete aircraft power-down / power-up will be necessary. This information is being included on FIM TASK 24-61-00-810-874-A, which will be available on the next FIM scheduled revision.

CF34-10E, Aft Engine Mount Wear


There are some field reports received by EMBRAER concerning aft engine mount wear as shown in the pictures below.

Observed wear on engine Aft Mount related to thermal blanket

The maximum wear depth reported was 0.008 inches.

The wear observed is related to the thermal blanket contacting the aft engine mount in the following location identified in the next pictures:

Location of contact on blanket

For this issue, GE is recommending: “lightly tapping blanket with rubber mallet provides more clearance.”


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The current wear limits are in CF34-10E Engine Manual, 71-20-02 Aft Engine Mount, inspection 001 (4. Visual inspection, subtask 71-20-02-220-001, F. All other areas for: wear).

There is a proposal to revise these current limits to provide more flexibility regarding wear limits and blending procedures to the operators.

This manual revision is planned to be available by Temporary Revision in December/ 2007.

The proposed modification is:

- Max repairable depth = 0.030 inches

- Blended depth not to exceed 0.040 inches

- Blend anywhere along Surface A

- Smooth blend fading into original surface contour

- No hard limit on length and width

- Following blend

– Etch

– Spot FPI

– Rotary Flap Peen blended area

• SPM 70-47-04

Blended Area according to EMM

Fault Isolation Procedure to Clear an External AC Power Connection Issue


EMBRAER has been informed of some events of the External AC Power not supplying energy to the aircraft. In order to isolate this kind of fault, FIM TASK 24-42-00-810-817 was created to check the operational condition of each component and hardware that comprises the External AC Power System.

In some of theses cases, the troubleshooting actions were confused by the spurious maintenance message EXT PWR (OPEN NEUTRAL)/WRG FAULT which may have improperly led to the accomplishment of FIM TASK 24-42-00-810-814-A.

In order to clarify this issue, EMBRAER has issued SNLs 170-24-0025 and 190-24-0019.

SNLs 170-45-0005 and 190-45-0005 were also revised to include this maintenance message as spurious message are under investigation status.

FIM TASK 24-42-00-810-814-A will be revised to clarify this scenario and to provide a link to the accomplishment of FIM TASK 24-42-00-810-817-A, which will be available in the next FIM scheduled revision.

Such spurious maintenance message is under investigation and being evaluated to be corrected through a new LDI version.


Page 7

"SPDBRK LEVER DISAG" Message


EMBRAER has been receiving some reports of "SPDBRK LEVER DISAG" CAS message and, eventually, causing some removals of the speed brake levers.

However, EMBRAER would like to advise that no maintenance action is required and, if the message is latched on the ground or any other Flight Control Systems message is active, the FIM task must be followed.

A Service News Letter will be issued in order to inform the operators about the correct actions for this message.

Brake Assembly New Part Number


Regarding the brake carbon disk issues found during EMBRAER 170 service, EMBRAER informs that the operator has a new option to convert the brake assembly during next overhaul. SB 90000583-32-05 was issued on 28/August/2007 by ABSC for the EMBRAER 170 series aircraft.

The rotating disks have tungsten-carbide (low friction) coated rotor channels and revised carbon machining. These coated rotor channels will reduce friction and wear at the wheel key-to-rotor channel interface and will reduce wheel loads into the rotor.

The Pressure Plate has improved oxidation protection to minimize the oxidation impact.

Brake assemblies 90000583-1, 90000583-1PR, 90000583-2, and 90000583-2PR are fully interchangeable. The new and used carbon disks can not be intermixed.

Pylon Heat Shield Improvements


Pylon heat shield damage due to high temperature and vibration has been reported since the beginning of the EMBRAER 170 operation.

Service Bulletins SB170-54-0004 and SB170-54-0005 were issued to replace portions of the inboard skin and trailing edge of the pylon aft fairings (which were initially made from composite or aluminum) with new ones made from stainless steel).

These service bulletins also give instructions to apply a thermal insulation protection and perform a structural re-design of the aft pylon fairing shields.

After the release of SB170-54-0005, during the assembly of the first rotable set, a mismatch between new heat shield skin 1 and further parts was verified. A new part is under development and SB170-54-0005 will be revised to include this modification.

Although SB170-54-0005 is available, it is recommended to wait for the next revision.


Page 8

CF34-10E7 EGT Exceedances


A CF34-10E7 operator has experienced EGT exceedances during derated takeoffs on hot days. Most of the EGT exceedances have occurred using TO-3 fixed derate option and a few exceedances have occurred with TO-2. No exceedances have occurred with TO-1.

The engine exceedance events that were analyzed demonstrated the following characteristics:

• Hot day phenomenon (all exceedances occurred at ambient temperatures above +27°C).

• Predominantly occurs early in the morning, 1st takeoff of the day.

• Not limited to a single engine.

• A temperature inversion was noted during the exceedances (temperature increases instead of decreasing during climb).

• A system issue, not an engine turbomachinery issue.

Based on the analysis of the provided data, the main contributors to the engine exceedance events were, so far, determined to be:

• Temperature inversion.

• The TO-2 and TO-3 redlines being too low.

• Difference between the OAT set and the ambient temperature at the actual TO time.

A control plan was proposed by EMBRAER and GE to minimize the operational impact. Work was also done in order to propose ways of simplifying performance calculations and to minimize maintenance burden in case of an engine exceedance event.

GE and EMBRAER are working on the final corrective action, which is expected to be included in the next FADEC Software Version.

Rudder PCU pressure reducer test (HML)


EMBRAER advises that in order to perform the functional test of the rudder PCU pressure reducer as per AMM II TASK 27-22-01-720-803-A, the ADS SIMULATOR (GSE 056 and GSE 361) must not be used in place of AIR DATA TEST SET (GSE 144).

The purpose of this test is to check the hinge moment limiting (HML) functionality, simulating the PCU pressure transition as a function of airspeed with an anemometric bench (GSE 144). The test also aims to check the functionality of the HML circuitry relay, harness, and ADSP discrete signal.

The actuator pressure reducer is disabled when the flight control system is operating in NORMAL MODE. When operating in DIRECT MODE (no gain schedule is available), the pressure reducer function is automatically enabled whenever the airspeed is above 160 knots restricting the hydraulic pressure within the actuator, thus, limiting the rudder surface to operate at low rate.

For the Rudder Power Control–Unit – Functional Test (HML) - AMM II TASK 27-22-01-720-803-A, the GSE 021 and GSE 144 must be used, as shown in the next pictures

1) GSE 144 - AIR DATA TEST SET


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2) GSE 021 - KIT - AIR DATA ACCESSORIES

Slat 4 Harness Inspection SB


SB 190-30-0002 was released at the end of August. It describes an inspection for Slat 4 Outboard Electrical Harness, regarding a known issue that may lead to anti-ice related messages.

EMBRAER would like to advise that EMBRAER AMS (Air Management System) Engineering is revising this SB to improve its text and add a relief-period for the inspected aircraft that presented out-of-SB-limits harnesses, but without evidences of damage (harness integrity is granted) or failure in the anti-ice system (e.g. A-I WING FAIL /LEAK CAS messages).

Integrity Tests (I-BIT) Tips


EMBRAER advises all operators that during the execution of steps 2 and 9 of the Flight Control Systems PCU Integrity Test – AMM Task 27-00-00-710-801-A, the FCS daily switch function must be completed (Odd or Even Day Engage) before continuing the test.

The FCS daily switch function is initiated as soon as all 3 hydraulic systems are pressurized. During this period of time the HYD PBIT routine is running and should not be interrupted. Then, only after the HYD PBIT is finished, will the FCS daily switch function configuration be done.

Odd Day Engage

Even Day Engage

In addition, EMBRAER recommends waiting at least 2 minutes to have the HYD PBIT done, as required in the steps 2 and 9 (refer to the following pictures).


Page 10

Step 2

Step 9

Refueling panels indication lamps lighting during pre-check of the pressure refueling procedures


Usually, EMBRAER 170 / 190 new operators have concerns about the required time difference between each lamp of the refueling system panel to light during the pre-check.

The main function of these lamps is to indicate the status of the pressure refueling shutoff valves for each wing tank, respectively. Before beginning any refueling procedure, the normal status of these lamps is not illuminated (shutoff valves open). When the fuel nozzle of the refueling source (truck, cart, or any other mean) is attached to the adapter assembly of the refueling panel, each lamp will become illuminated (shutoff valves closed) as soon as the fuel nozzle’s valve handle is in the open position, pressurizing the fuel system (refer to AMM PART II 12-11-01-03 for proper and detailed instructions on how to proceed with pressure refueling).

Since the fuel nozzle attaching point is positioned in the RH wing tank, it is expected that the RH TANK indication lamp in the refueling panel will always be the first one to be lit, due to the proximity of the RH shutoff valve (closer than LH shutoff valve). It is very common to notice a time difference between the lighting of the lamps. This amount of time has been one of the concerns of the new operators.


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In fact, there is no table specifying the correct time interval between the lighting of the two lamps, once it varies according to different conditions, such as:

• Pressure delivered by the refueling source (truck, hydrant, cart, or any other);

• Variation of the assembly tolerances of each shutoff valve from aircraft to aircraft;

• Fuel chemical and physical characteristics (density and temperature variation, etc.);

• Other minor aspects.

The countless refueling configuration possibilities makes it nearly impossible to create a time table, but it is important to be aware that the lighting interval DOES NOT represent a system malfunction in the expected scenario described above.

Therefore, operators can have confidence in the aircraft refueling system, since it’s assuring that each shutoff valve closes again when the selected quantity of fuel in each tank is reached. Nevertheless, it is always important to remember that the refueling pressure shall be between 35 (thirty five) and 50 (fifty) psig, in accordance with EMBRAER Technical Publication and, as a reference, with the placards installed inside and outside of the access door panel of the pressure refueling system.

Acronyms

ACM = Air Cycle Machine

ACMF = Aircraft Condition-Monitoring Function

AD = Airworthiness Directive

ADS = Air Data System

AICC= Auxiliary Integrated Control Center

AIPC = Aircraft Illustrated Parts Catalog

AMM = Aircraft Maintenance Manual

ANAC = Agência Nacional de Aviação Civil (Brazilian Civil Aviation Authority)

AOM = Airplane Operations Manual

APU = Auxiliary Power Unit

CAS = Crew Alerting System

CMC = Central Maintenance Computer

CMM = Component Maintenance Manual

DLS = Data Load System

EDP = Engine Driven Pump

EGT = Exhaust Gas Temperature

EMM = Engine Maintenance Manual

FADEC = Full-Authority Digital Engine-Control

FAM = Flight Attendant Manual

FCS = Flight Control System

FHDB = Fault History Database

FIM = Fault Isolation Manual

FOL = Flight Operations Letter

GCU = Generator Control Unit

HML = Hinge Moment Limiting

LDI = Loadable Diagnostic Information

LICC = Left Integrated Control Center

LRU = Line Replaceable Unit


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MAU = Modular Avionics Unit

MMEL = Master Minimum Equipment List

MRB = Maintenance Review Board

OB = Operational Bulletins

PCU = Power Control Unit

PN = Part Number

PSEM = Proximity Sensor Electronics Module

PSU = Passenger Service Unit

RICC = Right Integrated Control Center

SB = Service Bulletin

SN = Serial Number

SNL = Service Newsletter

SPDA = Secondary Power Distribution Assembly

WHCU = Windshield Heating Control Unit

WM = Wiring Manual

Note: All abbreviations used in EMBRAER Maintenance Manuals can be found in the Introduction to AMM Part II.

operator e-jets news rel 12

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