Avionics News November 2015 - 14
Continued from page 13
News & Regulatory Updates
Advanced NPA issue for CAR 521
The Transport Canada Civil Aviation has been working on a revision to CAR 521 since 2010 with several
consultations both internal and external. Due to many
other governmental priorities, it has not been able to
progress as quickly as it would like. In the last several
months, it has been preparing an NPA based on all the
feedback received. An advanced NPA to revise CAR
521 was issued in July of this year covering 10 issues
that were identified over this period:
1. Clarification of terminology and administrative
2. Alternate method of data approval.
3. Definition of threshold for a major design change
to CAN-TSO articles.
4. Issuance of special conditions-airworthiness for
an auxiliary power unit.
5. Clarification regarding requirements associated
with reporting and investigation of service difficulty reporting.
6. Clarification on part design approvals requirements.
7. Addition of early ETOPS as an optional approval
granted as part of a type certification for transport category airplanes.
8. Expansion in applicability for a flight test operations manual.
9. Addition of requirements for function and reliability test flights to normal category turbojets.
10. Clarification regarding requirements associated with validation and acceptance of foreign
In total, there are 90 proposals for changes to the
text of CAR 521. In most cases, there are changes
to the wording to provide better clarification to the
intent, such as changing conformity to compliance and
the reintroduction of major and minor design change
terminology. In all the revisions, there are three significant proposed changes that may affect the modification business.
One proposal is to revise 521.154, which covers
minor design changes, to remove the applicability to
design approval holders and to include wording that
it indicates minor changes may be approved with procedures acceptable to the minister. The wording, as
such, seems to indicate all minor changes regardless of
who does them need to be completed by this method.
It may be in conflict with AWM 571.06, which states
that minor changes can be completed by anyone using
acceptable data. The intent of the acceptable data was
to allow those in the field to make the determination
on what was acceptable. Additionally, the revision is
meant to clear the issue with respect to a delegate being
able to approve a minor change. The intent is to make
it clear that anyone who has acceptable procedures
for minor changes can produce data that meets the
definition of "acceptable data." However, the current
proposed wording may have unintended consequences
and further restrict a modification shop from carrying
out minor modifications. This would further affect
Canadian shops with respect to competing with U.S.
shops. One of the overall goals of the TCCA has been
to provide a vehicle that would even the playing field
between Canadian and U.S. shops.
Currently, there are specific documents identified as acceptable to be used to identify an approved
design. The proposal in this NPA is to allow for other
forms to be used to approve major design changes.
Currently, CAR 521 only identifies a type certificate,
STC, RDA and TSO approval. This revision would
allow delegates to create procedures and a document
that would identify an approved major design change,
thereby opening the door to "one-off approvals" as
was done 20 years ago.
The final significant change is for the definition
and requirements of a certification plan. The current
wording is restrictive in the sense that it implies the
applicant would have a complete product and definition of the product at the time of application. In reality,
throughout the program, several changes are made. The
intent is to better define what a certification plan truly
is intended to do. It recognizes the fact that compliance
is not yet demonstrated and all the details may not be
known at the time of application. However, it is trying
to implement requirements such that the applications
are made at an advanced stage of the program.
The plan with this advanced NPA is to gather comments as of Sept. 26, 2015, and then carry out faceto-face meetings. Also, all comments made during the
NPA process will be provided to the CARAC members
for review. A final NPA will be drafted for acceptance
by CARAC, although no proposed date has been set.
You can review the advanced NPA at http://