Foreign designs: following the evidence through a TDE

Keep three statements separate. First, the source work was conducted under an acceptable framework. Second, its configuration, role and environment make it applicable to the Canadian case. Third, the chosen depth of type design review addresses the remaining uncertainty. Recognition can help with confidence in another authority, but its scope matters and does not approve a Canadian design. An acceptable report can still be inapplicable. A relevant report can still need further review if its assurance or substantiation is insufficient.

Why this case matters

A foreign design arrives with certificates, reports and a long service history. The useful question is what those records actually establish for the Canadian aircraft. This workshop follows a fictional mission-installation acquisition through an evidence review. It is deliberately a training scenario: its proposed findings are not decisions made by the TAA for a real fleet.

Follow the evidence

Why the TDE Exists: No Automatic Acceptance

DND "regularly acquires aeronautical products or adopts design changes that are based on previously certified or qualified designs," and in those cases "much of the work to certify those designs has already been completed by another airworthiness authority or competent design organization"; the TAA is therefore "prepared to give maximum credit ... provided that the work is acceptable to the TAA" (TAM 2.5.1.2(1)-(2)). But acceptance is earned, never presumed: "until the TDE activities have been successfully completed, it cannot be automatically assumed that airworthiness approval from other airworthiness authorities are acceptable to the TAA" (TAM 2.5.1.2(3)). The TDE's ambition is equivalence - to give certification work performed by other organizations "the same validity as if the work had been performed by the TAA" - and its product is a credit determination that "may be applied towards gaining airworthiness approval, in accordance with Part 3, Chapter 2 [design changes] or Part 2, Chapter 1 [type certification]" (TAM 2.5.1.1(3)).

What can be credited is broader than whole-aircraft type certificates. The TDE chapter contemplates credit for the spectrum of another authority's approvals - foreign type certificates, supplemental type certificates, repair design approvals and repair design certificates, and parts design approvals among them (TAM Part 2, Ch. 5, para. 2.5.1) - which is why the same process serves a new-fleet acquisition, a foreign-developed modification, and a foreign-approved repair. This breadth is the practical substance behind the loose claim that "Canada adopts FAA-certified designs": the TAM path is always TDE credit toward a DND approval, and the TAA's own FAQ states it directly - approvals from other authorities do not automatically have the same validity as TAA approvals; credit is assessed through the TDE. The credit determination itself can be made by TAA staff or by individuals the TAA has authorized, including the Senior Design Engineer of an Acceptable Technical Organization or Acceptable Design Organization (TAM Part 2, Ch. 5, para. 2.5.1.1).

Part 1 - Assessment of Acceptability: Substituting for a Missing Bilateral

Civil regulators lean on bilateral agreements: TCCA holds formal arrangements with the FAA and EASA under which each authority's certifications are accepted against defined procedures. DND has no civil-style bilateral airworthiness agreement with the US military - or with any foreign military authority. The TAM says so structurally: the TDE "expands the definition of the organizations whose work may be acceptable to include foreign military airworthiness authorities, original equipment manufacturers, and competent design organizations," and includes "an activity called Assessment of Acceptability" precisely because of "the absence of agreements between DND and other airworthiness authorities" (TAM 2.5.1.2(4)-(6)). The Assessment of Acceptability asks whether "the standards, processes and procedures used during the original certification program are acceptable to the TAA" (TAM 2.5.1.3). The primary input is the recognition status of the originating authority under Joint TAA-OAA Advisory 2016-04e-v7: a MARQ-assessed, formally recognized authority (the USAF Technical Airworthiness Authority, NAVAIR AIR-4.0P, the US Army Airworthiness Authority, the UK MAA, Australia's DASA, and others, plus TCCA/FAA/EASA on the civil side) gives the acceptability assessment its foundation. Recognition is not transferable comfort, though - the Advisory's sovereignty caveat is blunt: "Safety and airworthiness are sovereign responsibilities. Recognition, therefore, does not transfer any legal responsibilities from the TAA-OAA to the recognized AA" (Advisory 2016-04, para. 4.3.1).

The recognized-authority list itself (Advisory 2016-04, Annex A) rewards study. On the military side it spans Australia's DASA, Italy's DAAA, New Zealand's DAA, Spain's DAA (including DGAM and INTA), the UK MAA, and the three US service authorities - the USAF Technical Airworthiness Authority (AFLCMC/EN-EZ), the Department of Navy Airworthiness Authority (NAVAIR, AIR-4.0P) and the US Army Airworthiness Authority (AMCOM). On the civil side sit TCCA, the FAA and EASA - recognized "based on their regulatory experience and reputation, without requiring a formal recognition process" (para. 4.4.1), with other civil authorities accepted by exception, leveraging TCCA's and the FAA's bilateral agreements. Two practical readings follow. First, the originating authority for your program is almost certainly on this list already - the TDE's acceptability question is usually about *which* layer of that authority's work applies, not whether the authority is competent. Second, the list is versioned and alive: Annex A and Annex B entries have changed over time (the current revision is v7, May 2025), so verify status at program start rather than inheriting a predecessor's assumption.

Part 1 (continued) - Assessment of Applicability: Configuration, Role, Environment

Acceptability answers "was the original certification done competently?" Applicability answers the harder Canadian question: "does that certified design match the aircraft Canada will actually operate?" The Assessment of Applicability determines whether "the original design and associated certification work are applicable to a DND registered aeronautical product" - probing differences in configuration, role and environment (CRE). Advisory 2016-04, Annex A Notes 2 and 4 make the rule permanent even where credit is maximal: design approvals from recognized authorities for similar aircraft types "will normally be given full credit by the TAA," but "an assessment of applicability must always be performed to determine if any additional certification work is required to address differences ... related to the destination DND aircraft's configuration, role and environment." CRE gaps are where foreign credit stops and new Canadian certification work starts: a transport certified for benign civil routes needs fresh substantiation for tactical low-level operations; a helicopter certified for land-based utility needs shipboard environment work; a fighter certified to US Navy mission profiles may not carry the life assumptions of Canadian usage - the CF-188 fatigue experience covered later in the course is exactly that failure mode.

Part 2 - The Type Design Review: Levels 1, 2, 3

TDE Part 2 is the Type Design Review (TDR), scaled to risk at one of three levels (TAM 2.5.1.3(4)). Level 1 - Minimum Review grants full credit without examining the underlying technical data: the review works from top-level documents only - the original Type Certificate, any STCs, the Type Certificate Data Sheet, the Approved Flight Manual, the MMEL. Level 2 - Limited and Level 3 - Comprehensive reviews dig progressively deeper into substantiating data where the acceptability or applicability assessments surface questions. The linkage to recognition is explicit: "In the context of TDE, recognition can be used to support determinations of Acceptability and will influence the level of Type Design Review required (Level 1 - Minimal, Level 2 - Limited, or Level 3 - Comprehensive)" (Advisory 2016-04, para. 4.2.4). A recognized authority plus a clean CRE match argues for Level 1; an unrecognized OEM, a weapon-system-specification pedigree, or significant Canadian-unique modifications pushes the review toward Level 3. Who conducts the work matters too: individuals authorized to conduct TDEs and grant credits include the Senior Design Engineer (SDE) of a TAA-acceptable technical or design organization - one more example of the program's pattern of assigning technical airworthiness authority to organizations and individuals rather than centralizing every finding in DTAES.

The TDE's product is a report the rest of the system can build on: which certification work is credited, at what review level, with what exclusions, and what additional certification work the applicability assessment identified. That output feeds two downstream chapters. For a new type, the credit applies "towards gaining airworthiness approval" under Part 2, Chapter 1 - the DND Type Certificate program. For an in-service change, it applies under Part 3, Chapter 2 - design change certification (Day 11), where a foreign-approved modification is still treated as major and the TDE completes the DND approval. In both directions the credit is bounded by its own findings: credit granted for the basic vehicle says nothing about the mission suite; credit granted at Level 1 on document review says nothing about areas the documents did not cover. Reading a TDE report means reading its exclusions first.

Twelve-minute project workshop

• Spend three minutes drawing the baseline and Canadian configuration. Include installation, software version, role and environment; highlight differences that affect the evidence.
• Spend four minutes creating an acceptability/applicability ledger. For each report, write its origin and assurance, the configuration it covers, the claim it supports and the unresolved gap.
• Spend three minutes proposing a review depth for one affected area. Explain the uncertainty that justifies it and what further data could change your recommendation.
• Spend two minutes drafting a bounded conclusion. State credit that may be useful, gaps needing disposition and the authority that must agree the approach.

Compare your reasoning

A good ledger does not label the entire package accepted or rejected. It separates useful baseline evidence from installation differences, unfinished reports and recognition-scope questions. The preliminary report has a status problem, the antenna report an applicability problem, and the recognition statement a scope problem. A new test may be appropriate, but only after identifying what it must demonstrate; repeating every prior test without that analysis is also weak. Compare this reasoning with the documented CH-147F example in the ADSM, then identify what the public record leaves unspecified.

Keep your worksheet as an optional learning aid. It is not submitted or graded. The practice below has no pass mark and does not affect core course completion.