AFS-14-294-E

Exemption No. 11054

UNITED STATES OF AMERICA

DEPARTMENT OF TRANSPORTATION

FEDERAL AVIATION ADMINISTRATION

WASHINGTON, DC 20591

 

In the matter of the petition of 

 

BOMBARDIER AEROSPACE Regulatory Docket No. FAA-2014-0327

 

for an exemption from § 135.152 

of Title 14, Code of 

Federal Regulations 

 

DENIAL OF EXEMPTION

 By letter dated May 15, 2014, John Kotnjek, Manager, Airworthniness, Bombardier 

Aerospace, 400 Cote-Vertu Road West, Dorval, Quebec, Canada, H4S 1Y9, petitioned the 

Federal Aviation Administration (FAA) on behalf of Bombardier Aerospace (Bombardier), for

an exemption from § 135.152, Appendix F, parameter No. 5 (Normal Acceleration (Vertical))

of Title 14, Code of Federal Regulations (14 CFR) to the extent necessary to allow U.S. 

operators of certain CL-600-2B16 aircraft to operate those aircraft without complying with the 

recording rate required by Appendix F for that parameter. While the petition requests relief 

from Appendix F requirements, relief is actually required from §135.152, which requires 

compliance with Appendix F. The FAA has considered the petition as requesting relief from 

those requirements. 

The petitioner requests relief from the following regulation:

Section 135.152 prescribes, in pertinent part, that except as provided in paragraph (k) of that

section, no person may operate under part 135 a multi-engine, turbine-engine powered 

airplane or rotorcraft having a passenger seating configuration, excluding any required 

crewmember seat, of 10 to 19 seats, that was either brought onto the U.S. register after, or was 

registered outside the United States and added to the operator's U.S. operations specifications 

after, October 11, 1991, unless it is equipped with one or more approved flight recorders that 

use a digital method of recording and storing data and a method of readily retrieving that data 

from the storage medium.
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All of the airplanes identified in Appendix A to the petition were manufactured after 

August 18, 2000, making the airplanes subject specifically to §135.152(i)(1), or after August 

19, 2002, making those airplanes subject to §135.152(j). 

Section 135.152(i)(1) prescribes, in pertinent part, that, for all turbine-engine powered 

airplanes with a seating configuration, excluding any required crewmember seat, of 10 to 30 

passenger seats, manufactured after August 18, 2000, the parameters listed in 

paragraphs (h)(1) through (h)(57) of the section must be recorded within the ranges, 

accuracies, resolutions, and recording intervals specified in Appendix F to part 135.

Section 135.152(j) prescribes, in pertinent part, that for all turbine-engine powered airplanes 

with a seating configuration, excluding any required crewmember seat, of 10 to 30 passenger 

seats, manufactured after August 19, 2002, the parameters listed in paragraph (a)(1) through

(a)(88) of the section must be recorded within the ranges, accuracies, resolutions, and 

recording intervals specified in Appendix F to part 135.

Appendix F to Part 135 prescribes that the recorded values must meet the designated range, 

resolution and accuracy requirements provided in the Appendix during static and dynamic 

conditions. Dynamic condition means the parameter is experiencing change at the maximum 

rate attainable, including the maximum rate of reversal. All data recorded must be correlated 

in time to within one second. Parameter 5, Normal Acceleration (Vertical) requires a 

sampling interval of 0.0125, or 8 times per second. Airplanes subject to §135.152(i) or (j) 

have the same recording requirement for parameter 5. 

The petitioner supports its request with the following information:

The petitioner states that, upon learning of a potential issue with the sampling rate of one of 

the parameters for its CL-604 aircraft operated under Part 135, Bombardier conducted an 

internal review that revealed a non-compliance with a single sampling rate. Specifically, 

Bombardier found that although the normal acceleration sampling rate is recorded by the FDR 

at the required rate of 0.125 seconds (8 times per second), the source data is only provided at a 

rate of 0.2 seconds per sampling (5 times per second). Bombardier states the data can be 

correlated to match the sampling requirement without compromising the information recorded 

and that it is the only parameter found to be affected. Upon completion of its investigation, 

Bombardier began working on a solution with the manufacturer of the equipment, Rockwell 

Collins. 

Bombardier states that it is fully aware that Part 135 applies to aircraft operators, not 

manufacturers and that the FAA does not typically grant exemptions to manufacturers for 

operational requirements. Bombardier also references a specific exemption granted to 

operators of certain Airbus airplanes (Exemption 10611(a)) and suggest that its circumstances

are similar enough to warrant a grant of exemption to Bombardier. Bombardier states that it 

is committed to providing a comprehensive solution for its U.S. customers, including
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publication of a Service Bulletin for operators to use to replace the Data Concentrator Unit 

(DCU) in order to meet the sampling requirements.

Bombardier requests that the FAA waive publication of its petition in the Federal Register 

because the exemption applies to a limited number of their aircraft, would not a set a 

precedent if granted, and because a delay in acting would “unnecessarily delay 

implementation of the solution for Affected US Operators.”

The FAA’s analysis is as follows:

The FAA has determined that good cause exists for waiving the requirement for Federal 

Register publication because the exemption, if granted, would not set a precedent. The FAA 

does not accept Bombardier’s reasoning that the number of airplanes affected determines 

whether a request for exemption needs to be published in the Federal Register. Nor does the 

FAA consider publication to be the cause of a delay in accomplishing a fix that is totally in the 

control of the manufacturer regardless of the FAA’s decision on a petition for exemption.

Although similar in nature, the present petition of Bombardier and the referenced Airbus 

petition differ significantly in scope. Both manufacturers identified a problem meeting the 

recording requirements of a single parameter and both showed that the required data could be 

sufficiently ascertained using extrapolation of other recorded data in the event the need arose. 

Each manufacturer stated its intent to publish a service bulletin that would correct the 

deficiency and bring the affected aircraft into compliance with applicable regulations. Such 

similarities are common to many flight recorder exemption requests, but there are significant 

differences between the subject petition and the Airbus grant referenced. 

Airbus identified 345 aircraft operated under 14 CFR part 121 regulations by 13 operators, all 

of which were directly affected by the condition described in its petition. All 13 U.S. 

operators and all 345 affected aircraft required exemption from certain part 121 rules in order 

to continue operation. Bombardier, by contrast, has identified 31 aircraft of U.S. registry that

are affected and that may be operated under part 135, but may also be operated under part 91 

rules. The actual number of aircraft being operated under part 135 was not ascertained by the 

petitioner, nor was the number of U.S. operators. Unlike the Airbus situation, the FAA has no 

way of knowing how many part 135 operators may need relief, nor how many Bombardier 

aircraft are involved. 

The particular Bombardier aircraft affected may be, as stated by the petitioner, operated under 

part 91; such aircraft have different flight recorder requirements and would not need a part 

135 exemption nor would they be eligible to receive one. An exemption granted to the 

aircraft, as the Airbus exemption was, would seriously confuse that issue and present a larger 

burden on the FAA. Both of these circumstances were relieved by the format of the Airbus 

exemption, not caused by it as it would be here. The Airbus format exemption placed a more 

significant burden on the principal inspectors of the affected operators, which was balanced by 

the FAA’s need to process and oversee 13 exemptions affecting hundreds of daily flights and 
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thousands of passengers. It was a decision by the FAA to use a different process based on the 

circumstances. It is not to be considered an option that a petitioner may request in every 

instance, especially when the number of aircraft and affected operators are not presented. 

Further, Bombardier included in its petition a request that the exemptions be transferable 

between operators, since the aircraft are often swapped between part 135 operators, or 

presumably, between a part 91 operator and a part 135 operator because the aircraft is 

qualified to operate under either part. The FAA rarely grants transferable exemptions. We 

would not allow transferability in these circumstances even if requested by an individual 

operator. The swapping of aircraft between operators is a safety issue, a significant burden on 

the agency, and serves no purpose other than as a convenient business practice for some 

operators. If an operator acquires a new aircraft, it may apply for relief. 

While we appreciate the effort of Bombardier to notify the FAA of a discovered 

noncompliance and to begin seeking relief for its operators, we do not find the circumstances 

warrant relief in the form requested. We suggest that Bombardier notify the operators of the 

affected aircraft of the flight recordation deficiency and lend necessary technical support (as 

detailed in its petition) to those operators in applying for individual exemptions. The FAA

will consider exemptions from part 135 operators that require relief for affected aircraft that 

are on their operations specifications. We will not consider exemptions for aircraft operated 

under Part 91. In no case will we allow exemptions that are transferable between Part 135 

operators, or between Part 91 and Part 135 operations by the same operator. 

The FAA’s Decision:

 In consideration of the foregoing, I find that a grant of exemption would not be in the 

public interest. Therefore, pursuant to the authority contained in 49 U.S.C. §§ 106(f), 40113 

and 44701 delegated to me by the Administrator, the petition of Bombardier Aerospace for an 

exemption from 14 CFR § 135.152 is hereby denied. 

Issued in Washington, D.C., on September 12, 2014

/s/

John S. Duncan

Director, Flight Standards Service

.