Pursuant to subsection 5.9(2) of the Aeronautics Act, and after taking into account that the exemption is in the public interest and is not likely to affect adversely aviation safety, I hereby exempt, Bombardier Inc., 400 Côte-Vertu West, Dorval, Québec, Canada (hereinafter “Bombardier”) from the requirements of 521.31(1)(d) of the Canadian Aviation Regulations (CARs) only with respect to the requirements of paragraphs 525.841(a)(2)(i) and (ii) of the Airworthiness Manual (AWM) and only for the Uncontained Engine Failure (UEF) case, subject to the conditions described below.
Paragraph 521.31(1)(d) of the CARs specifies standards of airworthiness for the issuance of a type certificate in respect of an aeronautical product.
Paragraphs 525.841(a)(2)(i) and (ii) of the AWM establish requirements for pressurized cabins and compartments to be occupied to be designed such that cabin pressure altitude limits not be exceeded following decompression from any failure condition not shown to be extremely improbable.
Details of the above provisions are provided in Appendix A to this exemption.
PURPOSE
The purpose of this exemption is to permit the Bombardier CSeries aeroplane models BD-500-1A10 (CS100) and BD-500-1A11 (CS300) to contain design features that allow the cabin pressure altitude to exceed 40,000 feet, and to exceed 25,000 feet for more than 2 minutes, after decompression from any uncontained engine failure condition not shown to be extremely improbable, whereby the applicable standards of the AWM are not met, and to issue the corresponding type certificate. This exemption does not permit a non-compliance with AWM 525.841(a) for any other system and structural failure events not shown to be extremely improbable.
APPLICATION
This exemption applies to Bombardier only as part of the basis of certification for a type certificate for the Bombardier CSeries aeroplane models BD-500-1A10 (CS100) and BD-500-1A11 (CS300).
CONDITIONS
This exemption is subject to Bombardier complying with all of the following conditions:
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For any failure condition not shown to be extremely improbable, other than the uncontained engine failure case, compliance with AWM 525.841(a)(2)(i) and (ii) must be demonstrated.
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Bombardier shall design the aeroplane so that occupants shall not be exposed to a cabin pressure altitude that exceeds the following after cabin decompression from an uncontained engine failure case:
Cabin Pressure Altitude
(feet)Maximum Total Exposure Time
( minutes)Above 41,000
0
Above 40,000
1
Above 25,000
3
Above 10,000
6
- In showing compliance, it may be assumed that an emergency descent is made in accordance with an approved emergency procedure. Bombardier shall apply a 17-second flight crew recognition and reaction time between cabin pressure altitude warning and the initiation of an emergency descent.
VALIDITY
This exemption is in effect until the earliest of the following:
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the date on which any one of the conditions set out in this exemption is breached; or
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the date on which this exemption is cancelled in writing by the Minister where he is of the opinion that the exemption is no longer in the public interest or that it is likely to adversely affect aviation safety.
Dated at Ottawa, Ontario, Canada this 8th day of February, 2013, on behalf of the Minister of Transport.
“Original signed by”
David Turnbull
Director, National Aircraft Certification
AARD
Civil Aviation
Appendix A
CANADIAN AVIATION REGULATIONS
Part V - Airworthiness
Subpart 21 – Division II – Type Certificates
Section 521.31 – Standards of Airworthiness
521.31 (1) For the issuance of a type certificate in respect of an aeronautical product, the standards of airworthiness, including the aircraft categories set out in subsection 521.27(1), are those specified in the following chapters of the Airworthiness Manual, as applicable:
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.
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(d) Chapter 525 — Transport Category Aeroplanes;
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.
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AIRWORTHINESS MANUAL
Chapter 525 – Transport Category Aeroplanes
Subchapter D – Design and Construction
Section 525.841(a) – Pressurised Cabins [Change 525-17]
(a) Pressurised cabins and compartments to be occupied must be equipped to provide a cabin pressure altitude of not more than 8,000 feet at the maximum operating altitude of the aeroplane under normal operating conditions.
- If certification for operation above 25,000 feet is requested, the aeroplane must be designed so that occupants will not be exposed to cabin pressure altitudes in excess of 15,000 feet after any probable failure condition in the pressurisation system.
- The aeroplane must be designed so that occupants will not be exposed to a cabin pressure altitude that exceeds the following after decompression from any failure condition not shown to be extremely improbable:
- Twenty-five thousand (25,000) feet for more than 2 minutes; or
- Forty thousand (40,000) feet for any duration.
- Fuselage structure, engine and system failures are to be considered in evaluating the cabin decompression