Aircraft noise


#104

You’d think with all the noise we suffer we’d of got a bit of the RAF anniversary flyover.

But no.


#105

Good point.
Assuming that the 3rd runway will take the same amount of traffic as each of the others, then we’ve got a 50% increase in aircraft noise a-comin!


#106

The City (LCY) flights are around 2,000-2,500 feet. The Heathrow flights (LHR) more like 4,500. The vapour trails are around 36,000.


#107

But the new runway will be further north so the approach won’t be over FH. I wonder if they’ll even use it for landings from the East as that would put more flights right over central London. I’m sure that’s all part of the consultation process docs etc.


#108

I think you’re right. I’ve been totally wrong about the destination of the aircraft which fly directly overhead, thinking they were headed to Heathrow. But since looking at the tracking link provided by ThorNogson and others, it’s clear that the constant stream of aircraft over Forest Hill is heading to LCY.

There’s a another programme https://www.flightradar24.com/ which gives live data without the 1 hour delay, and shows a whole range of aircraft - London is incredibly busy, I don’t know why flights form Birmingham and Manchester need to fly over London on the way to various European destinations. Also a lot of private aircraft.


#109

That would be a waste of “half” a runway. Most LHR landings are from the east (onto runways 27L and 27R) so there is zero chance of them not using 27North or whatever its designation will be.


#110

They could use the existing ones for landings, the new one for take offs. Frankfurt have one like this.


#111

Good point. That’ll teach me to post early on a Monday morning.


#112

The last few days have been examples of this - as you correctly say, every incoming flight to LCY passes directly over Forest Hill. (BBC weather says we currently have an East North East breeze.) There have been outbound Heathrow flights audible e.g. over Bromley, but not directly overhead.

2000 ft does seem low (I think that’s why I mistakenly thought they were larger aircraft). but does anyone know how the elevation is measured, and how accurate the info is on the trackers that are available to us?


#113

Looks like we might both be right (or wrong)

The easterly approach for the 3rd runway only comes in from the North. So that’s good.


#114

In a nutshell, it’s probably because, unlike what it might look like on flight tracking maps, the sky has more than two dimensions. Planes from Birmingham and Manchester in particular will be much higher up when flying over London, so you wouldn’t be able to hear them and probably not see them on most days. And because most planes fly at lower levels in and around London as they start or land at one of the six nearby airports, I would have thought the sky higher up is comparatively “empty” so the two don’t affect each other.

That said, air traffic control above London is regarded as the busiest on most complex in Europe at least, if not the world.

The reasons other flights high up are routed above London is most likely to do with their predefined routes and fuel economics.


#115

yes it does seem low, but I can’t see why City Airport’s own height data should be inaccurate to any significant extent.

You are right that we have had an extended period of easterly winds, so it has been much more noticeable how relentless the City flights are at just 2000 ft over Forest Hill. I have now counted a typical weekday’s City flights over Forest Hill for easterly wind operations on Friday 8th June. Starting at 6.30 in the morning with an inbound from JFK Forest Hill was overflown 142 times ending just after 10pm. The highest volume hours were 6-7pm (15) and 7-8pm (14). During this time, all flights followed the exact same route heading west over us, give or take just 100m or so deviation north or south.

You have also noted the Heathrow flights taking off - most near us go by at about 5000 ft or higher to the south of us. However, because they tend to be bigger than City planes, and are also climbing, the noise level is higher and therefore quite noticeable from further away. Combined with the City planes we have drawn a very short straw when the wind blows from the east the way things are.

This City Airport concentrated flightpath was introduced with no consultation with those it overflies in 2016.

The flightpath over us goes from south of Catford town hall, along just a few metres south of Stanstead Road, then directly over Horniman Gardens then on to Dulwich Common. Just two aircraft deviated from this route during that day, both flew a little further north, cutting Brockley Rise further north up towards HOP. Here is a map screenshot.


#116

I don’t mean to suggest inaccuracy.

The Flightradar24.com site has two kinds of altitude measurement - “calibrated” and “GPS”. I don’t understand the difference between these and would like to know how they work. It is interesting that incoming LCY flights are around 4,000 ft at Northfleet/Gravesend, then 2,000 at Catford. The 2,000 is maintained from Catford, over Forest Hill and then Dulwich. Now, I assume that Forest Hill itself has an elevation of 300-400 ft above Catford. Does this mean, therefore, that all the aircraft are ascending on approach to Forest Hill, in order to clear Forest Hill at 2,000 feet? Or is the ‘calibrated’ height based on something like a nominal sea-level ground zero value? Hope that makes sense.


#117

ah yes I see what you mean. I did have a little look around this and there are several ways that airlines express their height. The one I believe they are using in this case is 2000 ft above mean sea level (MSL). So at Catford (elevation about 100ft above sea level ) they are 1900 ft above the ground, while if you are standing on top of the Horniman ridge (300ft above MSL) they are just 1700ft above you. They maintain a constant level flight at 2000 ft above MSL throughout.

Another method to express height is height above ground level, which I believe they are not using in this case and would as you say mean they would have to ascend to clear the Horniman ridge by 2000ft.

One reason that City flights stay this low is to ensure height separation from the departing Heathrow planes heading east, and also from any arriving Heathrow planes circling in the landing stack at Biggin. Here is a map of easterly operations at Heathrow where you can see the departing planes in green which are at a much greater height than 2000ft when they get into Forest Hill airspace. You can also see arriving planes in red and the stack at Biggin. Planes leave that stack and head west before turning north and then landing at Heathrow.


#118

We noticed it early in 2017. Is there an actual start date in 2016? Some posters (Rachel Dunlop) have the start as January 2017.

Today the altitude is 100ft lower, according to Flightradar24 they are maintaining 1,900 ft ‘calibrated altitude’ or ‘indicated altitude’.


#119

Sorry for long post put FYI here is the corporate cut and paste BS line from City Airport after I complained about a particularly grating early awakening one Saturday. I didn’t bother responding as I I felt so powerless to affect change. I did join HACAN though.

London City Airport (LCA) takes its community responsibilities very seriously and the issue of aircraft noise is certainly of great importance to us. Your complaint has been logged under reference 119.2018

I would like to stress that London City airport has strict hours of operation, which are legally binding by its section 106 planning agreement with the London borough of Newham, these are as follow:

Between 06.30 and 22.00 hours on weekdays
Between 06.30 and 12.30 hours on Saturdays
Between 12.30 and 22.00 on Sundays
Between 09.00 and 22.00 hours on Bank Holidays

There are exemptions for aircraft using the Airport in an emergency and aircraft are permitted to take-off or land during the period of 30 minutes after the Airport closes for traffic where they have suffered unavoidable operation delays.

As well as a 24 hour closure period at weekends, an additional stringent restriction of a total of 2 aircraft movements between 06.30 and 06.45 hours and a further 4 between 06.45 and 07.00 hours is in place. Again this is legally binding under the airports section 106 planning agreement with Newham.

In recognition that aircraft operations can have an impact on London residents we have the most stringent noise management scheme of any airport in the UK, regulated by the London Borough of Newham (LBN). Examples of the steps we take to control noise are:

• Restricted use of aircraft types operating at LCA (i.e. only aircraft that can meet strict noise limits as per the noise categorisation system agreed with the LBN)
• Continuous operation of our Noise and Track Keeping (NTK) system
• Continued dialogue with airlines and aircraft operators aimed at adopting improved quieter operating procedures
• Maintained dialogue with local communities facilitated by the LCA Consultative Committee

LCA is a business airport and you will notice peak times. Most operations are in the morning between 7am and 10am and there is also a corresponding peak in the evening from 6pm to 8pm.

It is also worth mentioning runway usage at LCA. We have one runway at LCA, and depending on the direction the aircraft are departing, which is dictated by wind direction, the runway is given a different designator, 27 (westerly) or 09 (easterly).

Aircraft associated with LCA over your area are arrivals on Runway 09. Arrivals on Runway 09 typically fly east to west at a distance of approximately 6km south of the airport. Aircraft fly at an altitude of 2,000 feet at the point where they fly near your location.

The direction aircraft must take off to depart or approach the airport to land is dictated by the wind direction i.e. if there is a wind blowing predominantly from the East to the West at the airport then easterly operations will occur. As you might appreciate, the airport cannot control these elements so the direction aircraft will fly can change from day to day. Aircraft movement over parts of your area determined by wind and these areas will notice that when the airport is operating on Runway 27 (westerly) you will not see any aircraft using LCA over them. Recently the airport has been operating on runway 09 due to easterly winds and hence the reason you have noticed arriving aircraft into LCA.

Also, it is worth noting that only 30% of all departures/arrivals during a year are easterly operations (known as Runway 09 departures/arrivals) since the prevailing wind at the airport is predominantly from the West during the year. Therefore, 70% of flights from London City Airport do not fly near your area.

Finally, may I say again how sorry we are that you have been given cause to contact us, however I hope that this information has been of some assistance to you.

Kind regards

Harman

Harman Dhillon
Technical Operations Support Officer

Email:
Harman.Dhillon@londoncityairport.com
Website:
www.londoncityairport.com


#120

That feels pretty accurate to me - although at times I feel that free line is a few minutes further north when they overfly my house. It is ridiculous that it could be changed without any consultation at all. Where did those plans go beforehand? Or did they previously fly high enough that we didn’t notice

The elevation is an excellent point; with us being on a hill, they’re lower than 2000 feet when they pass overhead which also contributes to the noise.

I’d be interested to know what they do on days with very light airs or where they are north/southerly winds. The wind is about an F1 N at the moment and they still seem to be coming across. Is that to try to help balance the 70% so they can keep that stat as low as possible for those affected on the other approach?


#121

I believe City when they say they only begin operations at 6.30am - that means the earliest we should experience an arriving plane in the morning over Forest Hill is about 6.25 am, and that is borne out by my City incoming plane count of last Friday- and it would be an easterly wind day ( 30% of days). If you were woken before that, then it wold have been a Heathrow arrival flight on a westerly wind operations flight - they start earlier and have some night flight exemptions- this means we experience some much bigger Heathrow planes from 4.30/5am on occasion.

Many online sources confirm the City concentrated flight paths began in Feb 2016. I think it has taken me (and many others) a while to work out where the planes are going, coming from, how it varies according to wind direction, etc. This last couple of weeks seems to have been mostly east wind operations, giving us a consistent period of City arrivals which are specially noticeable when we have windows open and are outdoors.

not sure - there must be a clear operational process to make the decision but I haven’t found it anywhere yet. The 30%/70% is quoted widely. London City use it to defend against complaints from our area, saying we only get their arrival flights 30% of the time, ignoring the fact that we get all of their arrivals during that time (142 in one day last week) at a low altitude , along with some Heathrow take off noise to the south of us.

The other 70% of the time we get a proportion of Heathrow landings ( a whole different ball game) , from very early in the morning, which of course is nothing to do with City!

It seems the CAA is sitting on a report from City which required them to review the first year of operations of concentrated flight paths. Our main hope (re City flights) is that the CAA may require City to make some changes to offer respite to overflown communities. Which is something that Heathrow, to their credit, does.


#122

It would be good to be clear about this. Wikipedia has a number of altitude measures

There are several types of aviation altitude:

* Indicated altitude is the reading on the altimeter when it is set to the local barometric pressure at mean sea level. In UK aviation radiotelephony usage, the vertical distance of a level, a point or an object considered as a point, measured from mean sea level ; this is referred to over the radio as altitude .(see QNH)[2]
* Absolute altitude is the height of the aircraft above the terrain over which it is flying. It can be measured using a radar altimeter (or “absolute altimeter”).[1] Also referred to as “radar height” or feet/metres above ground level (AGL).
* True altitude is the actual elevation above mean sea level. It is indicated altitude corrected for non-standard temperature and pressure.
* Height is the elevation above a ground reference point, commonly the terrain elevation. In UK aviation radiotelephony usage, the vertical distance of a level, a point or an object considered as a point, measured from a specified datum ; this is referred to over the radio as height , where the specified datum is the airfield elevation (see QFE)[2]
* Pressure altitude is the elevation above a standard datum air-pressure plane (typically, 1013.25 millibars or 29.92" Hg). Pressure altitude is used to indicate “flight level” which is the standard for altitude reporting in the U.S. in Class A airspace (above roughly 18,000 feet). Pressure altitude and indicated altitude are the same when the altimeter setting is 29.92" Hg or 1013.25 millibars.
* Density altitude is the altitude corrected for non-ISA International Standard Atmosphere atmospheric conditions. Aircraft performance depends on density altitude, which is affected by barometric pressure, humidity and temperature. On a very hot day, density altitude at an airport (especially one at a high elevation) may be so high as to preclude takeoff, particularly for helicopters or a heavily loaded aircraft.

These types of altitude can be explained more simply as various ways of measuring the altitude:

* Indicated altitude – the altitude shown on the altimeter.
* Absolute altitude – altitude in terms of the distance above the ground directly below
* True altitude – altitude in terms of elevation above sea level
* Height – altitude in terms of the distance above a certain point
* Pressure altitude – the air pressure in terms of altitude in the International Standard Atmosphere
* Density altitude – the density of the air in terms of altitude in the International Standard Atmosphere in the air
https://en.wikipedia.org/wiki/Altitude#In_aviation

It’s a bit exasperating, I want to just ask what is the distance from the aircraft to Horniman Gardens when it is directly overhead. It appears that “Absolute Altitude” would come closest to that. Flightradar24.com offers “calibrated altitude” and (for a fee) “GPS altitude”. Does anyone have expertise about this? Also does anyone have an authoritative source for the elevation of Forest Hill or One Tree Hill?


#123

We’ve now got a change of wind direction to westerly, and the pattern of arrivals has changed. The first Heathrow flight I noticed went over at 5.58 - flying higher than LCY traffic, but these are jumbo jets so audible at 4.800 ft. At time of posting these are approx every three minutes.