Archived on 6/5/2022

Reporting Aircraft Noise over SE23 using the Explane App

ThorNogson
13 May '19

:information_source: Discussion continued from Aircraft Noise over SE23 [2019]

Fine weather again, don’t forget to keep logging complaints with London City. Here’s mine from today.

Once again I find it necessary to complain about the low altitude aircraft flying today over Forest Hill to LCY. They fly under 2000 feet, which is too low, create persistent repeated noise at around 60 db and interrupt greatly the enjoyment of the outdoors. Inevitably this happens during the fine weather that accompanies east winds in this area. I am also dismayed to see that LCY has applied to the CAA to put back by nearly a year the CP1616 process. This appears to demonstrate the lack of any urgency or concern by the airport for overflown residents, despite three years of record complaints and detailed representations to the airport by residents including from the Forest Hill Society following the introduction of concentrated low altitude flight paths over SE London.

London City are going through an Airspace Change process. They have applied to the CAA put back the process ’ in order to deconflict the engagement process with previously planned airport activity’. I would think this means their expected expansion plans in the forthcoming Masterplan, which they are prioritising ahead of addressing noise relief and flight paths.

Meanwhile here is a way we can all help to quantity the aircraft noise in our or any area, using a new app developed in Holland. Download Explane on to your smartphone, then simply point the phone mic at a noisy aircraft. It logs the noisiest 10 seconds, identifies the plane and you can then submit the data to their central database. The crowdsourced data is then analysed, shared and can be used to provide evidence of the need for change. This is so new that no one is using it for London City planes yet. I started today. Could a few of us start to build an evidence base that we can use to create more pressure for change? Anyone else care to try it and report back?

DevonishForester
13 May '19

I’ve just recorded a ‘quiet’ LCY incoming at 70 db. Next one sounded louder but the phone recorded 64 db.

applespider
13 May '19

3 came over in short order towards LCY. I recorded a 68 (before I read the bit about pointing the mic at the plane), a 73 and a 75 in 15 minutes. Alarmingly, they didn’t sound like the noisiest ones that I spot. For interest, I recorded a quiet period with birdsong and a little traffic noise and it came in at 55.

anon5422159
14 May '19

A post was merged into an existing topic: Aircraft Noise over SE23 [2019]

DevonishForester
13 May '19

Interesting that the App picked up a LHR incoming at 75db, which sounded much quieter than the early AM LHR aircraft

anon5422159
14 May '19

Thanks for sharing @ThorNogson. To keep things tidy, and to ensure the discussion on the Explane app can be shared easily on social media, I have split the Aircraft Noise mega-topic into three topics:

New visitors enter topics at post #1, so @moderators occasionally split mega-topics to ensure the most recent discussion is easier to navigate to. There are links at the top of each topic helping readers to get to previous discussions.

DevonishForester
15 May '19

Or does it log the peak db level during a 10 second recording?

On Tuesday 14th I was in the garden (planting out veg) and recorded several flights generally 75 - 80 range, the highest level was 86 db.

ThorNogson
15 May '19

I see measurements have started to appear on the website from SE26 4, SE15 5 and SE23 2. I think it has incorrectly got me in SE26 though I am in SE23, near the border. The ones from SE23 2 are very high.
One issue is that on the datasheet you can’t tell the destination of the plane- so we can’t distinguish on the website between planes arriving/departing Heathrow or London City. I’ve told the developer- the app was devised initially for Schiphol - perhaps double airport overflights do not occur there.

re measurement the Explane site says:-
If you touch the microphone at the start screen, a measurement is started for the duration of 10 seconds.

Choose the start of your measurement preferably in a way that the plane will pass you in these 10 seconds. Please keep your measurement pure and be careful not to measure any other noises.

If by accident you measure non-aviation noise, please don’t send the registration to our database. It would pollute our database and would make it less trustworthy.

The app only registers airplanes on a maximum attitude of 10.000 meters (30.000 feet) within a radius of 5 kilometers (3 miles).

There’s another noise metering app I have used called NIOSH, which gives more sophisticated noise measurement using iPhones, including noise averaging, commonly used in industrial settings and by the aviation industry.
https://www.cdc.gov/niosh/topics/noise/app.html

DevonishForester
16 May '19

Unfortunately the NIOSH app is only available on iPhone.

Using Explane, the height measurements seem pretty close to those on Flightradar24.com can anyone confirm that? If so, does this give weight to the accuracy?

anon17648011
16 May '19

I suspect the difference is the actual height above ground level vs the height above sea level. City Airport publish their altitudes using the latter, but most areas of Forest Hill are around 100ft above sea level and at the top of the Horniman hill it’s more like 330ft meaning the actual height of planes over houses, schools etc. is closer to 1600-1900ft, not the “minimum 2000ft” that LCY like to try and push publicly.

DevonishForester
16 May '19

I got feedback from Explane: the app takes height readings from the OpenSky Network database.

Sometimes the App reports “No Aircraft Captured” which is very frustrating as this typically happens with very loud very low LCY aircraft.

ThorNogson
28 May '19

I see a few people have been using the Explane App to log/crowdsource aircraft noise from London City Airport. Here is a small selection from one person - the map shows as directly under the flightpath. These are very high peak readings, all over 80db and I would think very disturbing when repeated every 5 minutes or so - which is what is happening this evening after the wind changed to easterlies.

anon17648011
4 Jun '19

Just to say that I’ve taken a few readings with the Explane App and what is interesting is that the (presumably older) twin prop engined planes are significantly quieter than the more modern jet engined planes (~65dB vs ~75dB on my readings), and this certainly reflects my own experience.

The reason I say it’s interesting is because one of LCY’s public arguments about what they are doing to reduce noise is “introduction of more modern quieter planes”. Ignoring for a moment my suspicion that the noise reduction they are referring to is likely to be modest at best and probably take decades to really be felt by people under the flightpaths, the evidence doesn’t seem to support it anyway. But then LCY ignoring noise concerns and releasing misleading PR is not exactly breaking news.

ThorNogson
5 Jun '19

their database is quite good. Selecting two SE23 postcodes from people under the London City flightpath, restrict altitude to under 1500m to exclude any Heathrow planes, it shows an average peak decibel count of 74.
A database report on which planes register the most noise is shown below. It is Embraer 170 and 190 - modern twin engine jets - which make the most impact here. BA Cityflyer is the airline that mainly uses these. I haven’t measured, but I agree about the twin prop aircraft. They seemed less noisy, and used to be spread around the skies over us prior to 2016, that’s why there were very few complaints to the Airport until then. Twin turboprop may be another matter - top of the table here by a small margin is a Bombardier De Havilland twin turboprop plane.

Incidentally this seems consistent with the data on noise made by Arriving planes published by NATS.
https://www.nats.aero/environment/aircraft-noise/representative-aircraft-lmax-data/

dlf75
5 Jun '19

Loudest at 80, 82 and 85 dB over HOP! No idea how accurate the app is, but will keep using it.

DevonishForester
6 Jun '19

I find that often the loudest LCY aircraft, right in my face so to speak, are the ones that Explane doesn’t capture. I sometimes have a second attempt which usually does work after the aircraft is no longer directly overhead.

DevonishForester
23 Jun '19

Again, this evening the LCY incoming are very loud but most show as ‘No Airplane Captured’ when my ears tell me there should be a 90 decibel reading.

anon17648011
24 Jun '19

There’s a note on the app from 17 June saying that because their database is updating a lot of flights will show as “no airplane”.

DevonishForester
24 Jun '19

Does anyone else have this issue? If not, maybe it’s phone-specific.

This evening especially noisy with LCY incoming as well as loads of Heathrow jets coming from various directions at 4000 - 5000 ft.

ThorNogson
14 Jul '19

hi Explane app users, a request,
any day we are overflown by London City, we could do with some Explane app noise measurement of the Airbus A220-100. This plane is cited by LCA as one of the new generation of quieter planes. I’d like to compare how noisy this is over Forest Hill with the usual Embraer 190s, of which we have plenty of data already logged and searchable on Explane.

A noise expert at LCY told me the other day that we might expect just 2-3 Db quieter for the new generation, in level flight over us at 2000 ft. The main noise gain from the new generation will mostly be heard on takeoff. This despite a claim in a recent LCA publication that they are 14DB quieter!

The only operator of this craft at LCA is Swissair who fly this plane on the Geneva- London City route, so if you have the time please get Explane dbmax readings wherever you are normally doing this, presumably in your garden.

We are, I think , on LCY easterly operations this afternoon, there is one due in at 16.40. On any day, Google Swissair Geneva -London City schedule to find when they are due.

If the data confirms that there is minimal change in level flight at 2000 ft it strengthens our argument that the Masterplan is misleading in claiming the future will be quieter for us. They say that only 75% of the fleet will be the quieter generation by 2035. O the other hand if this really is a ‘whisperjet’ their case is strengthened.

DevonishForester
28 Aug '19

I hope this is not an indication of things to come. I recorded an Easy Jet incoming to Luton, over Forest Hill at 01.27 this morning.