| Topic: | Aircraft engines and Hatton Cross monitoring station | |
| Posted by: | Thomas Barry | |
| Date/Time: | 15/03/14 21:51:00 |
| "And yet, a week on, no-one has even attempted a SWAG at the questions I asked." OK, here's one - there's a Hounslow AQM station at Hatton Cross just east of the threshold of Heathrow runway 27L, at which point planes are at a higher power level (due to having full flap and undercarriage down - at Putney they'll barely be idling) and obviously much lower. Putney is clearly worse for NO2 - at Hatton Cross's worst point this week it was registering 160 ug/m3 - at the same time Putney was around 250. Putney: http://www.londonair.org.uk/london/asp/basicgraphs.asp?site=WA7&sitename=Wandsworth__Putney_High_Street&period=Seven_day&graphdate=15/03/2014&species=NO2&graphtype=Java Hatton Cross: http://www.airqualityengland.co.uk/site/graphing?site_id=HS7 (and select the NO2 graph) This isn't to say air traffic doesn't contribute to NO pollution over London; clearly it does, but with a prevailing westerly wind and the altitude involved obviously it's going to be diffused rather than concentrated like the Putney figures suggest. [also big widebody planes with Trents like A380s, 777s and so on are a minority, the commonest planes at Heathrow are narrowbody Airbus A319/320/321 series with correspondingly smaller engines - the average plane is therefore somewhat less than a pair of Trents worth] |