Contracts in Regulated Industries: The Limits of Injunctive Relief in Transvalair‑Express v. DASH‑L
What happens when a NAV CANADA NOTAM conflicts with contractual obligations owed to airport users?
The Québec Superior Court’s decision in Transvalair Express inc. c. Développement de l’aéroport Saint‑Hubert de Longueuil (DASH‑L) brings that question into focus at Montréal Metropolitan Airport (YHU). On an initial application for interim relief, the Court refused to intervene despite an airport user’s lease‑based claim, underscoring a reluctance to disrupt existing operational frameworks pending a full determination on the merits.
While the court refused to grant an interim injunction, this will be a case to watch going forward.
The Dispute: Flights Schools and a Changing Airport
The plaintiffs, comprised of several pilot training schools, had operated at Saint‑Hubert Airport (now Montréal Metropolitan Airport, or MET) for decades under long-term leases and had made substantial investments in facilities and equipment. The dispute arose when DASH-L, as operator of YHU, sought to introduce operational restrictions through a NAV CANADA NOTAM in advance of Porter Airlines’ commencement of commercial service on June 15, 2026.
The restrictions at issue were:
limits on departures during peak hours;
advance booking requirements; and
constraints on departure frequency.
The plaintiffs argued the measures reduced their operating capacity by up to 65–70%, threatening the viability of their training programs. They sought a provisional injunction restoring access on a “first‑come, first‑served” model and restraining further constraints.
The Legal Framework
The Court applied the familiar four-part test for interlocutory injunctions:
serious issue to be tried;
serious or irreparable harm;
balance of convenience; and
urgency.
As the Court noted, the threshold for the first element is relatively low. A claimant need only demonstrate that the case is neither frivolous nor vexatious and raises a genuine issue for determination on the merits.
On that basis, the Court found a serious issue to be tried. The claim raised a legitimate dispute concerning peaceable enjoyment under the lease and the parties’ good faith obligations under the Civil Code of Québec, particularly insofar as those obligations may extend to ensuring functional access to airport infrastructure.
The Court also accepted that the plaintiffs had shown a risk of serious harm. It noted that irreparable harm includes harm that cannot easily be compensated in damages, or that would be difficult to quantify. The evidence supported that the NOTAM restrictions would significantly curtail flight operations, impair the plaintiffs’ ability to meet obligations to students, and threaten the viability of their businesses.
Urgency was likewise established. The Court emphasized that urgency requires a situation of immediate and apparent peril, and that parties must act with diligence once that risk materializes. Here, the restrictions were introduced with minimal notice, leaving little practical opportunity for the plaintiffs to mitigate their effects before they came into force.
In short, these elements did not present a meaningful barrier. As is often the case in interlocutory proceedings, the outcome ultimately turned on the balance of convenience.
The Decisive Factor: Balance of Convenience
The application was dismissed as the Court held the balance of convenience favoured maintaining the NOTAM and the operational status quo.
Importantly, the Court viewed the dispute as having broader operational implications beyond the immediate interests of the parties. An injunction would not simply affect YHU and the flight schools. It would disrupt structured scheduling, affect commercial airline operations, and have consequences for passengers and the broader aviation system. The airport’s transition to commercial service, approved at the ministerial level, was treated as presumptively aligned with the public interest.
The Court also placed significant weight on safety considerations. NAV CANADA’s role as the air traffic management authority was central. The Court accepted that the restrictions were necessary to manage increased traffic within limited infrastructure and to permit training and commercial flights to coexist safely. Removing structured controls could cause delays, cancellations, safety risks, and strain on air traffic control. On an interlocutory record, the Court was not prepared to interfere with that framework.
Contractual Rights in Context
The decision reflects the well‑established principle that lease‑based rights are not absolute, particularly in regulated environments. Peaceable enjoyment may include functional access to runways, but that access is conditioned by the airport operator’s obligations to manage traffic, ensure safety, and comply with regulatory requirements. As such, contractual rights must be assessed in the factual and regulatory context in which they operate.
Signals for the Merits
Although interlocutory, the judgment provides meaningful guidance on the likely trajectory of the dispute. The Court noted potential issues with the adequacy of notice to tenants and YHU’s engagement with affected operators, which may support a lack-of-good faith argument at trial.
However, the available remedies are likely to be structurally limited. Even if liability is established, the Court is unlikely to dismantle the NOTAM structured scheduling, impose a “first‑come, first‑served” regime, or require parity between training flights and commercial operations.
If the plaintiffs ultimately succeed, the more realistic outcomes are compensatory damages or enhanced consultation and coordination mechanisms. The Court’s endorsement of a voluntary multi-stakeholder coordination framework suggests that structured cooperation may be more realistic than judicial management of runway access.
Potential Implications for Other Airport-Use Disputes
The reasoning in Transvalair‑Express has relevance beyond Saint‑Hubert/MET. Airport-use disputes often sit at the intersection of leases, operating agreements, regulatory approvals, safety obligations, land-use constraints, and federal aviation oversight. Where those layers interact, courts are likely to be cautious about using interim injunctions to freeze or unwind operational changes.
That caution may matter in the disputes surrounding Billy Bishop Toronto City Airport. Billy Bishop is governed through a distinctive tripartite structure involving the Toronto Port Authority, the City of Toronto, and Transport Canada, and public debate has focused on governance, runway capacity, aircraft restrictions, waterfront impacts, and consultation. Those features make it a useful comparator: the claim may be framed through land rights, contractual governance, consultation, or municipal authority, but the remedial analysis will likely turn on operational and public-interest consequences.
Parties challenging airport expansion or access restrictions should be cautious not to equate a strong merits claim with entitlement to interlocutory relief. Where the requested order would affect scheduling, safety compliance, passenger reliability, or broader transportation planning, those considerations may weigh heavily against an injunction.
Conversely, airport operators and public authorities should not treat the decision as permission to disregard affected users. Inadequate notice, deficient consultation, or bad faith implementation may still support liability. The point is remedial: process failures may lead to damages, declarations, or structured consultation obligations, but not necessarily an order that destabilizes an airport’s operating model.
From the perspective of airport operators and public authorities, the decision emphasizes the value of building a comprehensive record supporting operational decisions, including statutory authority, safety imperatives, consultation processes, and public interest impacts. Where such a record is established, courts are likely to defer to the existing operational framework rather than assume a role in allocating airport capacity.
Takeaway
Transvalair‑Express demonstrates how private law rights operate when embedded in complex, regulated systems.
The Court’s message is straightforward: credible contractual rights and even substantial harm will not necessarily justify provisional relief where the remedy would disrupt the operations of safety-sensitive public infrastructure.