© Airbus SAS, 2014. All rights reserved. Confidential and proprietary document. This document and all information contained herein is the sole property of Airbus SAS. No intellectual property rights are granted by the delivery of this document or the 

disclosure of its content. This document shall not be reproduced or disclosed to a third party without the express written consent of Airbus SAS. This document and its content shall not be used for any purpose other than that for which it is supplied.

Airbus SAS

Société par actions simplifiée

au capital de 2.704.375 Euros

RCS Toulouse 383 474 814

Registered office:

1, rond-point Maurice Bellonte

31700 Blagnac, France

François DUCLOS

T +33562118541

F 

E françois.duclos@airbus.com

Our Reference: G28M14025456

Your Reference: 

8 December 2014

U.S. Department of Transportation

Docket Operations, M-30

1200, New Jersey Avenue S.E.

Room W12-140, West Bldg, Ground Floor

Washington , DC 20590-0001

USA

Petition for a time limited exemption from section 14 CFR 25.981(a)(3) Amendment 125 and 

from section 14 CFR 25.901(c) Amendment 126 for the A330-300 Fuel Center Tank activation 

change to Type Design

Dear Madam / Sir,

Airbus is hereby petitioning for a time limited exemption from one provision of section 14 

CFR 25.981(a)(3) Amendment 125 – Fuel Tank Ignition Prevention – and of section 14 CFR 

25.901(c) Amendment 126 – Installation - for the A330-300 aircraft models which will be 

modified to activate their fuel center tank capability (refer to FAA project n°AT10200IB-T). In 

order to ease the review of this exemption request, the petition has been formated as per the 

guidelines of § FAR 11.81.

(a) Name, mailing address and other contact information

François DUCLOS

A330/A340 Chief Airworthiness Engineer

Airbus SAS

D2202

1 rond-point Maurice Bellonte

31707 Blagnac Cedex

France

(b) The specific section or sections of 14 CFR from which exemption is sought

A time limited exemption is sought from the ‘no single failure in combination with probable 

(i.e. with a probability greater than extremely remote) latent failure condition’ provision as 

stated in sub-paragraph (a)(3) of section 14 CFR 25.981 – Fuel tank ignition prevention – at 

amendment 125 (‘Demonstrating that an ignition source could not result from [...] each single 

failure in combination with each latent failure condition not shown to be extremely remote’) 
© Airbus SAS, 2014. All rights reserved. Confidential and proprietary document. This document and all information contained herein is the sole property of Airbus SAS. No intellectual property rights are granted by the delivery of this document or the 

disclosure of its content. This document shall not be reproduced or disclosed to a third party without the express written consent of Airbus SAS. This document and its content shall not be used for any purpose other than that for which it is supplied.

From François DUCLOS Date 8 December 2014 Reference G28M14025456 Page 2

and interpreted by the FAA for section 14 CFR 25.901(c) - Installation – (‘it must be established that no [...] probable combination of failure will jeopardize the safe operation of the 

airplane’) . 

(c) The extent of the sought relief and the reason for seeking this relief

Airbus is seeking a 12 months relief for incorporating in production on the concerned A330-

300 aircraft models a fuel system design that is fully and directly compliant with section 14 

CFR 25.981(a)(3) and 25.901(c) requirements identified above. The design changes identified as necessary for demonstrating full compliance following reviews with the FAA will indeed not be ready for incorporation on the first A/C delivered to the US launch customer, 

Delta Airlines (first aircraft delivery currently targeted for end of May 2015). These design 

changes include:

Extensive airplane wiring installation changes in the aircraft fuselage with impact on 

the aircraft structure in order to segregate the center tank Fuel Quantity Indicating 

System (FQIS) wiring from other airplane wiring with a physical separation distance

Addition of a second Ground Fault Interrupter (GFI) for each of the center tank fuel 

transfer pumps power supply

The 12 months relief is requested from the date of first A330-300 delivery to Delta Airlines, 

i.e. based on current delivery planning up until end of May 2016. At the time of petitioning, it 

is estimated that around five aircraft would be delivered to Delta Airlines during this exemption period. There is no intention to retrofit these first five aircraft.

(d) The reasons why granting the request would be in the public interest; that is how it 

would benefit the public as a whole

Denial of this petition for exemption would imply a delay of several months in the delivery of 

the first A330-300 with fuel center tank activated to the US launch customer, Delta Airlines. 

This would therefore deprive Delta and its flying customers from the benefits brought by 

these aircraft which will allow carrying more payload on longer missions. Denial would also 

have negative impacts on the numerous US suppliers of Airbus (as an example, UTAS, 

A330/A340 fuel system supplier) due to the delivery delays. 

For these reasons, granting the request would benefit the US public as a whole.

(e) The reasons why granting the exemption would not adversely affect safety

The baseline design for the A330-300 fuel center tank is the well proven design of the A330-

200 and A340-200/300 aircraft models (which has now accumulated more than 30 million of 

revenue flight hours) with all SFAR 88 corrective actions mandated by the FAA including the 

fitment of a Ground Fault Interrupter (GFI) on the power supply of the two fuel transfer 

pumps. The same Flammability Reduction System (FRS) as designed for the A330-200 and 

A340-200/300 will also be incorporated, limiting the center tank flammability exposure to levels below 0.5%, i.e. well within the requirements of 14 CFR Appendix M25.1 at amendment 

125.

In addition to this already safe baseline design that will be embodied on the first aircraft delivered to Delta Airlines, Airbus has voluntarily defined additional airplane wiring design im-
© Airbus SAS, 2014. All rights reserved. Confidential and proprietary document. This document and all information contained herein is the sole property of Airbus SAS. No intellectual property rights are granted by the delivery of this document or the 

disclosure of its content. This document shall not be reproduced or disclosed to a third party without the express written consent of Airbus SAS. This document and its content shall not be used for any purpose other than that for which it is supplied.

From François DUCLOS Date 8 December 2014 Reference G28M14025456 Page 3

provements in the frame of the activation of the A330-300 fuel center tank. These improvements, listed below, will also be incorporated in the first aircraft delivered to Delta Airlines:

Addition of clamps on electrical bundles in zone adjacent to the centre tank in order to minimize the risk of chafing in case of an attachment point failure

Additional metallic overbraiding on the centre tank FQIS wiring in order to limit the 

level of induced currents in case of lightning strike

Additional electrical and mechanical protection sleeve on the centre tank FQIS 

wiring in order to prevent the risk of induced current from short circuits due to the 

co-routing with other low energy non intrinsically safe (28VDC) airplane wiring 

For the FQIS wiring installation, those additional changes will already raise the level of robustness of the A330-300 modified areas against the risk of creating a fuel tank ignition over 

and above the already currently flying safe baseline. Compliance to the higher certification 

standard of section 14 CFR 25.981(a)(3) Amendt 125 and to section 14 CFR 25.901(c) 

Amendt 126 will be demonstrated except for the ‘no single failure in combination with probable (i.e. with a probability greater than extremely remote) latent failure condition provision 

due to the following extremely improbable specific residual risk: a foreign object or undue 

contact with an adjacent structure damaging the FQIS wiring protection sleeve and causing a 

short circuit between FQIS wiring and low energy non-intrinsically safe wiring outside the fuel 

tank in combination with a latent in-tank short circuit due to the presence of foreign object

that would create an ignition source due to the filament heating phenomenon, during a period 

where the fuel tank is flammable (i.e. thanks to the FRS less than 0.5% of the Flammability

Exposure Evaluation Time).

Based on these considerations, it can be determined that the design changes necessary to 

reach full compliance will be embodied on a design configuration which is considered as 

providing already an adequate level of safety. Therefore, granting the exemption to allow 

additional time to incorporate them and to deliver the first aircraft without later retrofit action 

will not adversely affect safety. 

As far as the fuel transfer pumps GFI are concerned, the basic design incorporated on the 

first A330-300 with fuel center tank activated has already been demonstrated to be compliant 

with section 14 CFR 25.981(a)(3) at amendment 102 and section 14 CFR 25.901(c) (refer to 

ELOS memo TD0764IB-T-P-1). Section 14 CFR 25.981(a)(3) at amendment 125 is unchanged compared to amendment 102. However compliance has been found by the FAA 

using an alternate (ELOS) methodology and the FAA notified Airbus that direct compliance to 

section 14 CFR 25.981(a)(3) at amendment 125 and section 14 CFR 25.901(c) would be 

required for the A330-300 fuel center tank activation project . Additional design changes (addition of a second GFI on each transfer pump power supply) are necessary to achieve this 

direct compliance. Those changes will be embodied on a design configuration which has 

been already demonstrated as safe, based on In-Service experience. Granting this exemption to allow additional time to incorporate them and to deliver the first aircraft without later 

retrofit action will therefore not adversely affect safety.

(f) A summary that the FAA can publish in the Federal Register

Airbus seeks a time limited exemption from section 14 CFR 25.981(a)(3) at amendment 125

and from section 14 CFR 25.901(c) at amendment 126, for the activation of the A330-300 

fuel center tank capability (FAA project n° AT10200IB-T).
© Airbus SAS, 2014. All rights reserved. Confidential and proprietary document. This document and all information contained herein is the sole property of Airbus SAS. No intellectual property rights are granted by the delivery of this document or the 

disclosure of its content. This document shall not be reproduced or disclosed to a third party without the express written consent of Airbus SAS. This document and its content shall not be used for any purpose other than that for which it is supplied.

From François DUCLOS Date 8 December 2014 Reference G28M14025456 Page 4

More precisely, Airbus seeks an exemption of 12 months (from first aircraft delivery date currently targeted in May 2015) to incorporate in production the FQI wiring installation and fuel 

transfer pumps GFI design changes necessary to reach full and direct compliance to section 

14 CFR 25.981(a)(3) and 14 CFR 25.901(c) (‘no single failure in combination with probable 

(i.e. with a probability greater than extremely remote) latent failure condition’ provision).

This request is in the public interest since it will enable to deliver the first concerned aircraft 

to the US launch customer on schedule thus benefiting the US public as a whole (Airbus US 

suppliers, US launch customer, Delta Airlines, and its flying customers). 

Granting this request will not adversely affect safety since the first few aircraft that will be 

delivered during the exemption period will incorporate a center tank Flammability Reduction 

System (FRS) that has been demonstrated to be compliant to section 14 CFR 25.981(b) at 

amendment 125 as well as additional airplane wiring ignition prevention improvements over 

an already safe design (as demonstrated by the satisfactory A330/A340 in-service experience). This initial design (available at first A330-300 with fuel center tank aircraft delivery) is

already very close to fully meet the latest certification standard, section 14 CFR 25.981(a)(3) 

at amendment 125 and FAA interpretation of section 14 CFR 25.901(c) at amendment 126.

The exemption will grant more time to incorporate additional changes determined with the 

FAA as necessary to reach full and direct compliance. At the time of petitioning, Airbus estimate that around five aircraft would be delivered to Delta Airlines during the exemption period. There is no intention to retrofit these aircraft which is acceptable from a safety standpoint 

for the reasons described above.

(g) Any additional information, views or arguments available to support the exemption 

request

Airbus request the FAA to waive the ‘publication and comment’ step in the exemption process. Indeed, Airbus consider that this petition is similar in intention and safety implications to 

time limited exemptions previously granted by the FAA to other applicants for section 14 CFR 

25.981(a)(3) at amendment 125 and section 14 CFR 25.901(c) at amendment 126. A quick 

treatment of this petition is necessary to enable timely certification of the A330-300 fuel center tank activation project by the FAA as currently scheduled for April 2015. 

 

(h) The reason to exercise the privileges of the requested exemption outside the United 

States if needed

Not needed, since this petition concerns a part 25 certification requirement and not an operational requirement

Yours faithfully,

François DUCLOS PE ARNAUD

A330/A340 Chief Airworthiness Engineer Certification Manager Propulsion