Response to Kyle:

Kyle suggests that the Q400 is much quieter, and that accounts for the wildly varying slot numbers we’ve seen.

Is there a real difference between the earlier Dash-8 aircraft and the Q400?  Not according to the ICAO, the international body that provides the noise data for most aircraft in use:

It says that the Dash-8-100 has noise on approach of 95.1 Effective Perceived Decibels (EPd, the Dash-8-300, 98.9 EPdB, and the Q400, depending on the model, between 93 and 94.9 EPdB. All are above the tripartite agreement’s maximum permitted level of 92.0 EPdB.

There’s a similar set of data for “lateral” or sideline noise: Dash-8-100 is at 86.3 EPdB, the Dash-8-300, 87.4 EPdB, and  Q400 is 84 EPdB. Again, all are above the tripartite agreement’s maximum permitted level of 83.5 EPdB.

All are obviously too loud, and the variance in levels isn’t so significant as to warrant the vast disparity among the various available studies of the permitted number of slots: from 97, to 112, to 120, to 167, and now, as of Christmas Eve, 212.

Unfortunately, notwithstanding our requests, neither the TPA nor Transport Canada will release the NEF study that Transport Canada conducted in 1989 (apparently dated October 1990). Release of that study – which is the last official study of NEF Contours – would be immensely helpful in getting to the bottom of what’s going on with this huge and nasty proposed expansion.

Part of the explanation has to be the predicted levels of other types of traffic. We note that the 167 figure was obtained in part by the elimination of flight schools at the airport. Perhaps helicopters will also have to go as well. Would private planes be next?

Brian Iler, chair
CommunityAIR