Thanks to Ken Lundy for responding.

The TPA suggests that “trade-offs” on noise limits are permitted by the ICAO, and are therefore permitted by the tripartite agreement.

Ken relies on this provision from the ICAO rules:

5.5.1 If the maximum noise levels[my emphasis] are exceeded at one or two measurement points:

a)      the sum of excesses shall not be greater than 3 EPNdB;

b)       any excess at any single point shall not be greater

than 2 EPNdB; and

any excesses shall be offset by corresponding reductions at the other point or points.

The authors of the ICAO rules would certainly not have had the tripartite agreement limits in mind when drafting this rule. Instead, the reference to “maximum noise levels” in this rule can only refer to the maximum levels established by the ICAO in section 5.5.1 of the ICAO rules – far higher than those set out in the Tripartite Agreement. The ICAO drafters could only have been referring to their own maximum noise levels.

To import that “tradeoff” in to the tripartite agreement, when it sets out very specific noise limits, it would have been necessary, in our view, to include explicit wording in the tripartite agreement such as “These levels may be adjusted in accordance with paragraph 5.5.1 of the ICAO rules, in the event one or more of these levels is exceeded”.

The parties to the tripartite agreement did not do so.

The limits are the limits, and can’t be played with to excuse clear breaches by the Q400 on two of the three.

Brian Iler, chair
CommunityAIR