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Design Approval

BAC Aerospace is dedicated to helping our clients obtain design approval for their aircraft.  Chris Baczynski, our founder and a former government of Canada aircraft certification expert in the field of aircraft propulsion, is a Transport Canada Design Approval Representative (DAR) specializing in powerplant installation, engines and aircraft noise.


Chris (on the right), working for TCCA, congratulating the P&WC program manager on the achievement of a Type Certificate 

As a Transport Canada aircraft certification delegate, Chris holds the necessary authorization to make your project a certified reality. In addition to Canada, our credibility and approvals are recognized by both the FAA and EASA, under the applicable bilateral agreements and their respective validation processes. 

Our technical focus area is aeronautical propulsion, with a scope of delegation that includes:

  • Powerplant specialty: engine-airframe integration and certification at the aircraft level, including engine installation, and all the associated systems, subsystems, components and functional areas, as well as environmental aspects of fuel venting and gaseous emissions. 


  • Engine specialty: design and certification of aeronautical engines, as opposed to their installations on aircraft, which fall under the powerplant specialty.

  • Noise specialty: testing and certification of airplanes and helicopters to aircraft noise regulatory requirements.

The above authorizations apply irrespective of propulsion type and include propeller-driven and jet airplanes, helicopters, and other designs*.  The delegation applies to both small (general aviation) and large transport categories of airplanes and rotorcraft.

* In case of new & novel designs, where the applicable regulations have yet not been published, the delegated scope may be negotiated on a case-by-case basis, as part of     the project certification plan review, and in consideration of the applicable special conditions.  

A more in-depth looks at what it all means

For management professionals seeking more information about these concepts, we offer below a brief explanation of design approval, aircraft certification, the role of aircraft certification delegates, and what is included in the powerplant specialty.  The information may also be helpful for startup companies looking to modify an existing aircraft or develop a new aircraft, including those involving electric propulsion.

Design Approval / Certification

Engine vs Propulsion System Certification

Delegate technical disciplines and scope

Scope of delegation

Design Approval / Certification


Aeronautical engineering is among the most tightly regulated industries.  All aircraft – including airplanes, helicopters, and other flight vehicles - and all aviation engines must have an approved Type Certificate (TC) to operate commercially and be eligible for sale. Similarly, any major changes need an approved Supplemental Type Certificate (STC).  Until the design is approved, the aircraft may only operate under an experimental permit, severely limiting its commercial viability.  The process of getting these design approvals is called aircraft certification.  It involves showing that the design complies with all the applicable regulatory safety design standards using various means such as regulatory design reviews, analysis, testing, and other methods. For a brand-new design, there are thousands of such requirements.  This number is usually much lower for a modification of a design, depending on the exact scope of changes.

The process is overseen by the government, in Canada specifically, by the Aircraft Certification branch of Transport Canada Civil Aviation (TCCA).  The detailed work is performed by industry delegates.  Those are recognized engineering industry experts who have been granted a “delegation of authority” by the Canadian government. The engineering delegates fall into two groups: full-time company employees, or independent consultants.

An independent delegate is called a Design Approval Representative (DAR) in Canada; the equivalent function in the USA system is called a Consultant DER.  The work of all delegates is checked by Transport Canada using a risk-based sampling approach called Level of Involvement (LOI).

Transport Canada requires companies applying to have their designs approved to either employ or have access to delegates with the necessary authorization to perform the job. Many otherwise promising projects were refused review by TCCA simply because the applying company did not meet that essential requirement.

Engine vs Propulsion System Certification

Contrary to common misperception, engine manufacturers cannot certify engine installations on aircraft. While they can help with installation design, they have no authority to determine regulatory compliance at the aircraft level. That is because engines and aircraft are certified to completely different sets of airworthiness requirements. In fact, a complete Type Certificate for an engine is just one of the several hundred additional regulations that apply to aircraft powerplant installations. Engine delegates work on certification of the engine itself. Powerplant delegates work on certification of engine installation on airplanes, helicopters, and other flight vehicles.

At BAC Aerospace, we have the delegated authority for both the powerplant installation and the engine fields, as well as and environmental regulations, including aircraft noise.


Delegate powerplant discipline

If you ever needed an open heart transplant, would you be comfortable with your dentist performing the operation, after all, a Doctor of Dental Surgery (DDS)? How about a psychiatrist working on your quadruple bypass?


Of course not; this sounds absurd. Yet, this need for specialists, so obvious and accepted in the medical field, is often overlooked by smaller companies trying to get complex aircraft modifications certified by Transport Canada – with disastrous results.


In aerospace, having a specialist delegate work on your design is just as paramount. While a delegate can adequately perform simple STCs without having single-discipline coverage, the more complex the modification, the more disciplines are affected.  

When it comes to engine and propeller installations, a powerplant DAR is a key specialist. The powerplant discipline covers all aspects and components necessary for propulsion or affecting the safety of propulsive function.


That includes, but is not limited to:

  • Engine installation

  • Propeller installation (if present)

  • Thrust reverses installation (if present)

  • Engine control system

  • Engine mounting 

  • Firewall

  • Cowlings

  • Inlet

  • Exhaust

  • Fuel feed

  • Oil system components & plumbing

  • Engine accessories

  • Engine ignition

  • Bleed air system

  • Drains within the powerplant compartment

  • Powerplant cockpit controls & instrumentation

  • Fire protection

  • Fire detection & extinguishing (if present)

  • Icing protection of the propulsion system

  • Etc.


On large projects, delegates need to work as a team.  The powerplant delegate works on the aspects listed above; the structures delegate works on structural elements, the electrical delegate works on the electrical system, and so on.  The bottom line is that all the affected and necessary aspects and disciplines must be considered for the certification project to succeed.

Scope of Delegation

Scope of delegation refers to the number, or breadth, of regulatory requirements a given delegate is authorized to sign for (make a finding of compliance). The scope can vary considerably between delegates, even if they work in the same technical discipline. Some can only sign for a dozen or so regulatory design standards, while others can sign for many hundreds. Basically, the wider the scope, the better, as long as it matches the technical discipline pertinent to the project.


As a former Transport Canada aircraft certification powerplant & engine expert and industry consultant, Chris Baczynski of BAC Aerospace holds the most extensive and comprehensive scope of delegation in the technical field of powerplant/propulsion in Canada.

design approval / cert
engine vs propulsion system
delegate disciplines
scope of delegation
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