December 20

th, 2013.

GCF-1939/2013 – 1/5

GNS/ra

EMBRAER S.A.

Av. Brigadeiro Faria Lima, 2.170

12227-901 - S.J. dos Campos - SP

Brasil

Fone: (12) 3927-0544

Fax: (12) 3927-1184

PC: 179 US Department of Transportation

1200 New Jersey Avenue, SE

West Building Ground Floor

Room W12-140

Washington, DC 20590

Subject: EMB-550 - FAA Type Validation

Petition to the Exemption from 14 CFR 25.1317(a) Amdt. 25-127

Embraer respectfully submits the enclosed Petition for a time-limited exemption for the 

EMB-550 from the requirement of 14 CFR Part 25.1317(a) as it relates to Powerplant 

control systems.

Best Regards,

Sérgio Augusto Viana de Carvalho

Airworthiness Director

c.c.: ANAC - GPC EMB-550
GCF-1939/2013 – 2/5

14 CFR 11.81 (a) - Contact Information:

Sérgio Augusto Viana de Carvalho

Embraer Airworthiness Director

Av. Brigadeiro Faria Lima, 2170 – PC 179

12227-901 São Jose dos Campos, SP - Brazil

Phone: 55-12-3927-3543

Fax: 55-12-3927-1184

14 CFR 11.81 (b) Specific Section from Which Exemption is required

§25.1317 High-intensity Radiated Fields (HIRF) Protection.

(a) Except as provided in paragraph (d) of this section, each electrical and electronic 

system that performs a function whose failure would prevent the continued safe flight 

and landing of the airplane must be designed and installed so that—

(1) The function is not adversely affected during and after the time the airplane is 

exposed to HIRF environment I, as described in appendix L to this part;

(2) The system automatically recovers normal operation of that function, in a 

timely manner, after the airplane is exposed to HIRF environment I, as described 

in appendix L to this part, unless the system's recovery conflicts with other 

operational or functional requirements of the system; and

(3) The system is not adversely affected during and after the time the airplane is 

exposed to HIRF environment II, as described in appendix L to this part.

14 CFR 11.81 (c) Extent of Relief and Reason for Seeking Relief

The engine control system is Level A classified and thus, needs to have its function not 

adversely affected during and after the time the airplane is exposed to HIRF 

environments I and II, also it should automatic recover its normal operation in a timely 

manner after the airplane is exposed to HIRF environment I unless this conflicts with 

other operational or functional requirements of that system.

In the case of the EMB-550, aircraft electrical and electronic systems which perform 

Level A functions were subjected to laboratory tests to verify that the systems and 

associated Level A functions are not adversely affected when the system is tested to 

the internal HIRF environment. Systems that perform Level A Control functions were 

also subjected to "on-aircraft" HIRF low level testing during the full aircraft HIRF test.

The resulting internal HIRF environments for level A systems are determined by aircraft 

attenuation to the external HIRF environments I and II. The attenuation is zone-specific 

and is established by aircraft test.

Motivation for exemption
GCF-1939/2013 – 3/5

During the aircraft development EMBRAER has used its own past experience, 

Guidance Materials such as ARP 5583, DO 160 E, AC 20-158 and the engine supplier 

experience to define the HIRF levels for which the Engine Control System would be 

required to be qualified. Based on this assessment it was defined that it should follow 

DO 160 E Cat Y, which presents the highest level for component qualification.

This assumption was to be validated by the aircraft tests, showing that the Control 

System had been qualified to a higher level than the one obtained on the aircraft test 

results. However, despite EMBRAER and its supplier knowledge on this subject, during 

conducted and radiated susceptibility tests in the aircraft, some higher levels were 

identified. 

So, EMBRAER conducted some additional tests to identify possible solutions to improve 

the installation protection against HIRF effects. As a result of these tests and 

complementary analysis some potential solutions were identified:

1. ECU (Engine Control Unit) re-qualification to the higher level obtained on the 

certification test; or

2. Inclusion of overbraid protection to all ECU harnesses; or

3. Inclusion of overbraid protection to ECU W1 and W2 harnesses and conduction 

of a partial re-qualification test of the FADEC system.

Due to the current phase of the aircraft development and certification process, 

EMBRAER has evaluated the impacts of each one of these design changes and requalifications activities, as follow: 

a. ECU re-qualification to the higher level obtained on the certification test: 12 

months after original engine Type Certification

b. Inclusion of overbraid protection to all ECU harnesses: 24 months after original 

engine Type Certification

c. Inclusion of overbraid protection to ECU W1 and W2 harnesses and conduction 

of a partial requalification test of the FADEC system: 12 months after original 

engine Type Certification

Based on the engine FADEC system qualification and results obtained on the 

complementary tests, an interim configuration is being proposed herein in order to allow 

certification schedule adherence.

14 CFR 11.81 (d) Reason Why Granting Relief would be in Public Interest

Public Interest:

The Embraer EMB-550 is designed to meet the business aviation market and Embraer 

respectfully submits this petition for exemption. Preventing this aircraft from competing 

in this market by denying this exemption, and thereby denying the required Type 

Certificate, would serve to eliminate competition in this aviation segment and would also 

drive up the costs to the operators in acquiring executive jets.
GCF-1939/2013 – 4/5

While the EMB-550 is not manufactured in the United States, a significant portion of the 

airplane, including the engines, mechanical systems, avionics, and interiors are 

manufactured by American suppliers. Denial of this exemption request would result in 

the loss of revenue for the American suppliers and have an adverse impact on the 

American balance of trade, both of which are counter to the public interest.

Finally, granting this exemption would not result in any reduction in the level of safety of 

the EMB-550/AS907-3-1E engine in comparison to other engines used in current fleet of 

transport category aircraft, especially when compared to earlier engines that were 

certified to a less severe HIRF environment. Since these earlier engines have shown a 

high level of safety in HIRF immunity, and since, even with the grant of this exemption 

petition, the level of immunity of the EMB-550 will be higher still, it is respectfully 

submitted that the requested conditional exemption would not be counter to the public 

interest on safety grounds.

In case of additional improvements are required, EMBRAER will issue a service bulletin 

recommending that all airplanes delivered during the effective dates of the time-limited 

exemption be retrofitted by December 31, 2018. The service bulletin will be available no 

later than December 31, 2016, such that all EMB-550 airplanes delivered under this 

exemption can order parts and install a compliant configuration. The relief sought is 

limited to EMB-550 airplanes delivered prior to incorporation of the compliant solution to 

production, which will be accomplished no later than December 31, 2016.

14 CFR 11.81 (e) Reasons Why Exemption would Not Adversely Affect Safety

As a condition for the granting of the requested time-limited exemption, Embraer will 

take the following actions to mitigate, as much as practicable, thrust control failures and 

to demonstrate that the risk of exempting such failures from the provisions of 14 CFR 

Part 25.901(c) is no greater than the risk from this failure that exists in the current air 

transport fleet of similar engine applications. 

EMBRAER will include an overbraid on the W1 and W2 harnesses, which allows the 

outboard ECU to be within the HIRF levels for which it has been qualified, and also 

assure considerable reduction of the HIRF levels for the inboard ECUs, being 

marginally out of the qualification levels in a very limited range of frequencies, as 

demonstrated during aircraft certification tests.

The architecture of the Engine Control system provides robustness for a safe engine 

operation with only one ECU channel working. If a specific condition of HIRF affects one 

ECU channel, the FADEC system is designed to detect faults and accommodate them 

using the redundant signals from the other channel, not affecting the system safe 

operation. 

Embraer offers the following justification in support of its Petition for exemption, 

substantiating how the proposed type design provides an acceptable level of safety and 
GCF-1939/2013 – 5/5

why granting the exemption will be in the public interest, as required by 14 CFR Part 

11.25.

1. The AS907 is a family of turbofan engines manufactured by Honeywell. The engine 

AS907-3-1E, which will be installed in the EMB-550 aircraft, is a derivative of the 

AS907-1-1A engine, which was initially certified by FAA in 25/Jun/2002. 

a. The configuration of the EMBRAER installation is quite similar to other AS907 

certified applications, which do not have overbraid on the ECU harnesses. 

b. The current certified AS907 applications have not experienced any event 

related to HIRF during more than 1,300.000 hours of engine operation. 

2. During the exemption effectiveness period, dispatch with one channel inoperative 

will not be allowed.

14 CFR 11.81 (f) Summary for Publication in Federal Register

EMBRAER requests to the time-limited exemption from 14 CFR Part 25.1317(a) Amdt. 

25-127 to allow certification schedule adherence. Certain design features would be 

required to ensure that the engine control system would not adversely affect safety.

14 CFR 11.81 (g) Additional Information to Support Request

Justification to Bypass Notice of Exemption Petition in the Federal Register

Because this petition requests only a time-limited exemption, the granting of this petition 

would not set any legal precedent. A delay in the granting of this exemption would delay 

certification and adversely affect operators who have made business plans based on 

the previously planned entry into service date of June 2014. For these reasons, 

Embraer requests that the FAA not wait to publish a Federal Register summary and 

solicit comments prior to the granting of this exemption.

Operation Outside of the United States

In accordance with 14 CFR Part 11.81(h), Embraer requests that the privilege of 

exercising this exemption for operation outside of the United States be approved. EMB550 are expected to be registered and operated in various countries throughout the 

world.

Conclusions:

In summary, EMBRAER believes that a time-limited exemption to 14 CFR Part 

25.1317(a) is the option which best serves the public interest and which provides an 

adequate level of safety which is not less than that of existing transport category 

airplanes.