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Backgrounder – The Tripartite Agreement .

By the Tripartite Agreement, signed in 1983, the City of Toronto leased the portions in green in this plan to what was then the City controlled Toronto Harbour Commission (THC), for a 50 year term, expiring June 30, 2033, with rent payable of One Dollar per year.



It is called a Tripartite Agreement because there are three parties, the City, the THC, and Transport Canada – it gets involved only if there is a decision to shut the Airport.


Against the wishes of the City, the feds restructured the THC as a federally controlled Port Authority (all directors save one from the City and one from the Province, are appointed by the federal government), under the 1999 Canada Marine Act, even though it did not meet the criteria to be included as a “port of national significance”.


The Toronto Port Authority rebranded itself as Ports Toronto a few years ago.


This Agreement contains the only constraints on Airport operations. It includes these:


1. De-icing fluid

No de icing fluid may be dumped into City sewer, contrary to para 20:

  • The Lessee shall not discharge, cause or permit to be discharged or howsoever to pass into the sewer systems, storm drains or surface drainage facilities at the demised premises, if any, or elsewhere any noxious, contaminated or poisonous substances.


2. Slots

Noise Exposure Forecast (NEF)measures cannot exceed a specified level. It is calculated by a complicated formula, and that’s the basis for the slot limitation.


On Christmas Eve, 2009, the Toronto Port Authority stated that its current consultant “anticipates” that up to 212 daily take offs and landings (slots) of large turbo prop aircraft are permissible at the Island Airport.


Based on information obtained by CommunityAIR, the slots available for large turboprops are either:

  • 97 per Transport Canada on July 21, 1998: - based on the use of the Dash 100 not the Q400 which is a much larger aircraft, or

  • 112 per consultant Sypher Mueller’s December 2001 report to the TPA – but states that even at that level, the NEF Contour would be breached, or

  • 120 per City of Toronto in 2003 and 2006 Tassé Report, or

  • 167 per airport consultant Pryde Schropp McComb in a 2005 report to Porter’s investors.


Ports Toronto now proposes to increase the number of slots from the current 202 to 246. No study has been provided to justify that.


3. Curfew

“The Lessee acknowledges and agrees that all flights into and out of the TCCA shall operate between the hours of 6:45 a.m. and 11:00 p.m., with the exception of medical evacuations and other emergency uses.”

There is a lack of clarity around aircraft operating on the ground within curfew hours – 11 p.m. til 6:45 a.m. Given the curfew objective of ensuring peace and quiet, that means no aircraft may be operating on land, in addition to taking off or landing. That is regularly breached as aircraft landing at 10:59 p.m. continue emitting engine noise well after 11 p.m. Ditto before 6:45 a.m. for aircraft preparing to leave.


4. Medevac

Note that only “medical evacuations and other emergency uses” are permitted in curfew hours.


Helicopters use the Island Airport as a base.


Since the helicopters deliver patients directly to hospitals, the Airport isn’t necessary for emergency helicopter use. An Airport isn’t needed for helicopters – they can be based anywhere.


Other medevac uses are non emergency – patient transfers from elsewhere. Patients are stabilized before they opt to be transported.


They can as readily be transported from Pearson.


5. Aircraft generating excessive noise are prohibited

To avoid any ambiguity as to what standard is used for this noise limit, the Tripartite Agreement references data issued by the International Civil Aviation Organization, the UN‐affiliated world body governing civil aviation.


A February 2009 PowerPoint presentation by the TPA to a now defunct community advisory committee meeting admits that even the Q400 (technically the Q402, flown by Porter and Air Canada) offends the Tripartite Agreement’s definition of aircraft generating excessive noise on two of the three limits. Breach of anyone prohibits the aircraft.


This is from that presentation:



Their only defence is that the ICAO rules permit averaging of the three noise levels. But those rules refer to averaging only to comply with ICAO noise limits, not those in the Tripartite Agreement.


6. Limited Commercial Service

The Tripartite Agreement restricts the TPA’s use of the Airport to “general aviation and limited commercial STOL service operations”.


"General aviation" is defined to consist of:

all civil aviation activities, other than a limited commercial STOL service, undertaken …. in the operation of civil, state and private (personal and business) aircraft; [and] the operation of … the de Havilland Dash 8 aircraft.

Civil aviation refers to non commercial flights – private aircraft, flying schools, etc. Transport Canada confirms that the Q400 is not STOL.


Both the TPA and Transport Canada take the position that, as the Q400 is classified “aeronautically” as part of the Dash-8 family of aircraft, and is therefore a Dash-8 for the purposes of the Tripartite Agreement.


When the Dash 8 was added to the Tripartite Agreement as a permitted aircraft (for “general aviation” purposes) in 1985, the only Dash 8 plane that could have been in the contemplation of the parties was the Series 100/200 – a 37 to 40

passenger plane – about half the capacity, and about 60% of the weight of the Q400, which was developed in the 1990s, and has very different performance characteristics .


The understanding of the parties at the time as to what they considered to be a Dash-8 is determinative, in law. The fact that the aircraft industry, and Transport Canada, consider the Q400 a derivative of the earlier Dash-8 models (and therefore within the family of Dash-8s) is strictly an administrative qualification and quite irrelevant to the correct interpretation of the Tripartite Agreement.


The City’s negotiator for the Tripartite Agreement told us during the campaign against jets:


My central concern is that the City has NO legal ability to control or influence what happens at the Airport except for the authority provided through its role as landowner. Through the 3 party agreements it enshrined 4 or 5 specific controls. Now it seems on the cusp of giving two of those away. I regard this as a very serious mistake with hard-to-measure long-term consequences.
Back in about 1980 the issue was framed as "STOL" (meaning commercial aircraft using, at the time, the 50-seat Dash 7) vs. "No STOL" (meaning an airport limited to general aviation and training flights, as had been the case up to that time). This was one of several key issues that differentiated Art Eggleton and John Sewell in their mayoral election contest, where Art committed to bring in "STOL with guarantees" if he became mayor. Sewell and others positioned allowing the Dash 7 as "the thin end of the wedge" or "allowing the camel in the tent" (though I now think "allowing the racoons to live in your attic" might have been a better metaphor!).



Brian Iler, CommunityAIR









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