LHR - Steeper Approaches trial 14 September 2015

[4listair]

http://www.heathrow.com/file_source/HeathrowNoise/Static/Steeper_Approaches_trial_fact_sheet.pdf


The international standard approach for most airports in the world is set at 3 degrees, except for obstacle clearance (e.g. buildings, mountains etc.). Recent experience at Frankfurt airport has demonstrated that slightly steeper approach angles are possible in the short to medium term to reduce noise for people living nearby.

Starting on 14 September 2015 we will be trialling an approach angle of 3.2 degrees. This requires no modifications to aircraft equipment or specific pilot training. The trial has been approved by the CAA and is planned to run until 16 March 2016.

[DaveReidUK]

According to the AIP, the trial actually starts on September 17th (AIRAC 1512).

The existing RNAV 3° approach will be withdrawn during the trial, though of course the conventional 3° ILS/MLS will continue to be available.

[ACMS]

Some Airlines like ours have strict stabilized criteria which can make it a challenge to follow the LHR speed control requirements. This 3.2 deg slope won't help that at all......:eek:

So it will be interesting to see how it goes for some LH WB operators......

[DaveReidUK]

Some Airlines like ours have strict stabilized criteria which can make it a challenge to follow the LHR speed control requirements.

Out of interest, do you use the current RNAV approach?

If you use the ILS, you can ignore the trial, it's not compulsory.

[MCDU2]

I am sure the trial will be a resounding success and the airport authority will already have their PR party piece at the ready to placate the tree huggers. Never mind that the reality of the situation will be aircraft shooting the glide with gear and speedbrakes thrown out much earlier and a significantly higher noise footprint as a result. And let's not get into fuel burn........

[Doug E Style]

Expect requests for the microwave approach to cease and be replaced with requests for the trial RNAV instead.

[CaptainSandL]

Increasing the glideslope at an airport purely for noise, in fact for anything for anything other than terrain, shows that the airport is not putting safety first. Pilots all know that an increased glideslope is more demanding, especially in a light headwind, and will increase the workload. Increased workload can lead to increased errors. This is nothing more than LHR trying to appease residents at the expense of flight safety.

The trail will probably prove a success because crew wont accept the steeper approach if the HWC is insufficient, on a training flight, marginal conditions, when fatigue levels are elevated etc, so the results in optimum conditions will look OK.

As MCDU2 says the crew will have to compensate by using high drag techniques which are high noise and you can kiss drag reduction techniques like Flap 3 goodbye.

Very poor show by LHR. Let us hope that other airports do not follow suit and 3.2deg does not become the new norm.

[Chesty Morgan]

Yep, that extra 50 fpm is gonna be a serious challenge. :rolleyes:

[Bobermo]

Chesty Morgan, exactly my thought. That extra .2 degrees won't make a huge differnce flying wise, if it helps noise wise it's worth a try!

[OldLurker]

From the expressions of horror from the pros, it seems that what looks to the layman like a tiny change (0.2 degrees) really is a big deal for them.

Does anyone have any experience or feedback from the Frankfurt trial?

[Juan Tugoh]

It is an additional, unnecessary factor to be managed on the approach with no safety gain. It means that there will be more unstable approaches with their consequent dangers but with no great benefit. There will be additional noise generated and the approaches will be less efficient and will burn more fuel so less environmentally friendly. None of which would be an issue if there was a performance issue that needed to be addressed like at Marseilles or Naples. However, the only reason here is to appease people that have made the choice to live near an major airport. The noise levels have reduced significantly since the 80s and we didn't do steep approaches then for noise abatement. This is all about politics and reason or sense will have no input to the argument. I suspect the decision has already been made and now we are having a trial to prove the case, i.e. the trial will be deemed to be a success or failure or whatever it is intended to be irrespective of the data.

[Chesty Morgan]

So 3.2 degrees isn't dangerous if there are hills around?

[NigelOnDraft]

3.0deg, 160 to 4, Airbus Flap 3, and stabilised by 1000R is all fairly marginal.

Throw in 3.2deg, and I wonder which of the others will give??

NoD

[ImageGear]

It's a cheap attempt to "sell" the third runway to already hacked off residents - nothing more, nothing less. Looks good as a news item but has no legs - it won't live past it's "sell by" date.:ugh:

Imagegear

[Chesty Morgan]

Indeed, Nige, one wonders how hundreds of 320 and 737 approaches everyday cope at Malaga with 160 to 3.8d on a 3.2 degree slope.

Go arounds and carnage are rife.

[deptrai]

There's quite a few "much more interesting" glide slopes due to terrain, and I don't think there is any real world evidence this is unsafe. 3.2 is within autoland certification limits of transport a/c (no coincidence there), and I agree it shouldn't be such a huge change from 3. Worth a trial. Who knows, maybe it could even sharpen the skills of some pilots...stay ahead of the a/c, and configure early.

(And actually I think it's an interesting question, whether the added noise from being fully configured earlier will be offset by the steeper slope. I'm curious to see the results)

[IcePack]

I know this is not the ils but there must be a reason the manufacturers put a slope limit for auto land. More "hard" landings I fear. Enhanced safety not.

[ASRAAM]

Chesty, my experience of Malaga is more limited than LHR but I would have to say that the controllers there generally have kittens if landing traffic is sequenced within 10 miles of each other. So although they ask for 160 till 4 it's not especially critical and most folks seem to fly the speed they need. If you slow early at LHR then it's likely you or the next aircraft will go around.

[HEATHROW DIRECTOR]

I know it's a long time ago but wasn't the 23 ILS at LHR 3.5 degrees?

[Sir Richard]

3.3 degree ILS 27 at Bombay never seemed to be a problem.

[kcockayne]

I have no idea of the physics of this. So, a genuine question; is an extra 0.2 degrees likely to make an appreciable difference ?

[DaveReidUK]

Expect requests for the microwave approach to cease and be replaced with requests for the trial RNAV instead.

What makes you think that will happen?

There has been a 3° RNAV approach available at Heathrow for some time now and it doesn't actually seem to be used that much.

[elandel]

I seem to remember Prestwick RW31 had a 3.5 degree GP...

[172_driver]

I have no idea of the physics of this. So, a genuine question; is an extra 0.2 degrees likely to make an appreciable difference ?

If the speed control was up to the pilot the 0.2 deg. wouldn't be an issue. At LHR the ATC puts you under strict speed control to achieve separation, e.g. 160 kts to DME 4. The idea that you can't go down and slow down is very true here.

Relating to my type, a solution would be to configure (extend gear and flaps) early. Now, due to excess drag, I would have to fly with partial thrust on which would negate the noise benefits.

The problem, as I see it, is not the glide slope angle. It's the glide slope angle with tight speed requirements and the current flying technique of keeping the aircraft in a low drag configuration as long as possible.

[NigelOnDraft]

Indeed, Nige, one wonders how hundreds of 320 and 737 approaches everyday cope at Malaga with 160 to 3.8d on a 3.2 degree slope.

Go arounds and carnage are rife. I can feel the sarcasm dripping ;)

My point is not safety - as above 3.2deg (and more) are perfectly safe. All I am saying is with LHR TBS, the real emphasis on 160 to 4 (and not earlier as most used to do), F3 approaches, and a "strict" 1000R (for some companies) stabilised approach, I do not seeing this achieving a noise aim... We'll either use more flap, take the gear early, slow up early or bust the SAC. None are safety issues I agree :ok:

[jack schidt]

Mauritius 14 is 3.8 then 3.5 deg and is perfectly stable (wide body EK and that's just my waistline).

This issue of political correctness in the world today concerning everything including pleasing people who decide to buy houses around airports is crazy. I can appreciate there is a noise issue but you the resident bought there so live with your decision, or move. To anyone who bought a property pre 1930 when it was called Harmondsworth I apologise and will try my hardest to be idle thrust over your house.

J

[Ellis Hill]

I thought they were about to withdraw the ILS for improvements and the only approach avail will be the RNAV?

Or did I mis read that?

[WindSheer]

I would guess there is a slight fuel saving per approach.....hence the reason BA are so interested.

That will be the REAL driver behind this project....

[DaveReidUK]

To anyone who bought a property pre 1930 when it was called Harmondsworth I apologise and will try my hardest to be idle thrust over your house.

If you habitually overfly Harmondsworth on either arrival or departure, then your thrust setting is the least of your problems. :O

I thought they were about to withdraw the ILS for improvements and the only approach avail will be the RNAV?

Or did I mis read that?

There is no suggestion that 3.2° RNAV approaches will be mandatory for any arriving flights. The conventional ILS, MLS and 3° PAPIS will continue to be available.

Pilots will, as usual, request their desired type of approach (ILS, Microwave or the trial 3.2° "RNAV Yankee") on first contact with Heathrow Director.

[Chesty Morgan]

I can feel the sarcasm dripping ;)

My point is not safety - as above 3.2deg (and more) are perfectly safe. All I am saying is with LHR TBS, the real emphasis on 160 to 4 (and not earlier as most used to do), F3 approaches, and a "strict" 1000R (for some companies) stabilised approach, I do not seeing this achieving a noise aim... We'll either use more flap, take the gear early, slow up early or bust the SAC. None are safety issues I agree :ok:

I agree, but as soon as you lot stop accepting 160 to 4 or start making more noise how long do you think the "trial" will go on for?

[NigelOnDraft]

I agree, but as soon as you lot stop accepting 160 to 4 or start making more noise how long do you think the "trial" will go on for? We are agreed :ok:

The "Go Around" option will be the result v the SAC. Not sure how much noise & fuel that will save :{

[FlyingStone]

3.0deg, 160 to 4, Airbus Flap 3, and stabilised by 1000R is all fairly marginal.

Throw in 3.2deg, and I wonder which of the others will give??

If you think you can't be stabilised according to your SOP with 160 to 4, just advise the ATC. Is it really that difficult to say "unable"?

[deptrai]

"I would guess there is a slight fuel saving per approach"

I seriously doubt that.

"There is no suggestion that 3.2° RNAV approaches will be mandatory for any arriving flights. The conventional ILS, MLS and 3° PAPIS will continue to be available.

Pilots will, as usual, request their desired type of approach (ILS, Microwave or the trial 3.2° "RNAV Yankee") on first contact with Heathrow Director."

It's a trial. How could you do a trial if you have no data to compare with. I have some faith airport bureaucrats can actually measure noise, and publish the data. Yes, people who buy a cheap property but don't like aircraft noise can seem a bit annoying, but if a 3.2 approach would help, why not give it a try.

[Cough]

Trial in winter -> Cold OAT -> NPA's are flatter than normal -> What is this going to prove?????

[pax britanica]

An earlier poster mentioned coping with an extra 50 fpm as a result of this, is that correct? If it is, and considering a final approach from say 6 miles out where the aircraft is currently at say 2000ft when it starts to 'descend on the glide' it takes say 2.5 minutes to fly the approach meaning that at 6 miles the aircraft is a mere 150 ft higher than today and close in the difference would be even less , From other posts it would seem that this small change still requires a bit more drag and therefore a bit more power and therefore noise it would seem the whole thing is a complete waste of time

[ZOOKER]

I think that the word 'planes' is used 4 times in the first 2 short paragraphs of the 'factsheet' says it all.

[EpsilonVaz]

4.8 into Innsbruck :D

[Right Engine]

Surely the real problem will be the preceding aircraft's wake using the 3.2deg profile whilst you are using minimum separation on the 3 deg?

[Del Prado]

"Pilots will, as usual, request their desired type of approach (ILS, Microwave or the trial 3.2° "RNAV Yankee") on first contact with Heathrow Director."

Please no! Don't start requesting ILS approaches, the first call is already too cumbersome.


With this talk of more drag earlier might one of the objectives of this trial be to reduce noise further out at the expense of more noise complaints closer in?

[pax britanica]

Del Prado

how could you suggest such a thing? Never happen in England would it , reducing noise for posh/middle class people in Kew and Richmond and increasing it for working class and large Asian population close to LHR in Hounslow

pb

[RAT 5]

Guys: I admit to not having read the whole discussion. Mea culpa.
I was operating out of a very noise sensitive EU airport for many years. Many major airports had a published low drag CDA profile. Having arrived from a UK operator, and been well taught, my standard profile was CDA low drag. My new local colleagues were not of the same thinking. There was no such philosophy in their region and no published CDA criteria. I battled to introduce it in the airline. Difficult. However, ATC didn't help with their early descents instructions. The ILS platform was 2000'agl. and my F/O's were dragging it in. At night ATC used 3000' for G/S intercept for noise reasons. I asked then why that wasn't also for daytime use. "Because it wasn't in the regs". I now sit and watch a/c drag it in at 2000' all day long. Daft for fuel, daft for noise, daft for environment. The locals are always complaining about noise. Why not raise the ILS platform to 4000'agl? The a/c are arriving from every which direction. If ATC want to cut you in short for spacing reasons, then they can ask for a CDA to whatever finals they need. Why is CDA not a universal airport thing? I've flown for airlines where CDA was SOP. I've flown into German airfields where low noise low drag CDA is published. Why is it not universal practice? This 3.2 slope instead of 3.0 slope is a piss in the pot for noise reasons. Start the slope at a higher height and keep idle thrust till 3.0nm. No level drag in. 3.0 or 3.2 from 6 or 8nm out is a gnat's cock of difference. 3.2 from 2500' agl or 3.0 from 3000' agl. Without the science I can almost guarantee that the latter is less noisy; from 3500' even less so. Is this experiment just another political sop to the uninitiated?

[DaveReidUK]

I've flown into German airfields where low noise low drag CDA is published. Why is it not universal practice?

Heathrow typically reports 85-90% CDA compliance.

[RexBanner]

RAT 5, exactly the same experience here. I came from a UK operator who pushed the CDA concept very firmly indeed. When I left, I then took the same practices out to a European operation. The looks on the faces of the captains there when I selected V/S and told them I was trying to achieve a CDA was quite the picture. It's a cultural thing, they just don't get it. The amount of them who used to fly the platform to glideslope interception in Luton in blatant disregard (or ignorance) of the requests for CDA's there was quite something.

[ManaAdaSystem]

Quote:Heathrow typically reports 85-90% CDA compliance.

Only for the portion below TL. And dragging it in at 300 feet/min is called CDA.
I think it's a bit weird, but your country and your rules.

[SLF3]

I live near Heathrow and bought my house in 1986. I got copies of the official approach and departure tracks (I still have the dye-line print) to make sure I was away from the flight paths. An ATC told me they were very unlikely to change. In 1986 there were very few flights after 8.30 pm at night. Since that time the departure tracks have changed and the number of flights has increased by 50%. Most of the extra flights are in the early morning and late into the night.

When I bought my house aircraft noise (and pollution related to the airport) was not an issue for me.

Please can we drop the argument that says 'you bought there so it is your fault'? When I bought it was reasonable to assume I would not be bothered by airport noise. I am. The air was clean. Now it is not.

[LLuke]

I bought my house next to a quiet railroad ;-)

[gardenshed]

Guys and Girls please also note that 160kts to 4nm etc is an ATC request, if you accept then you have to fly it.
If you cannot for any reason tell them, and tell them what speed profile, i.e. 160 to 5nm you can accept.
Remember you are in charge of the machine not them. I know that we follow what they say usually without question, and it works well. But at the end of the day the buck stops with you.

[WHBM]

Please can we drop the argument that says 'you bought there so it is your fault'? When I bought it was reasonable to assume I would not be bothered by airport noise. I am. The air was clean. Now it is not.
I don't think anyone has used the word "fault". But you did buy your house, as you say, near to the largest and busiest airport in Europe, then and now. I'm sure many other things have changed in the last 30 years. The open space you recall kids playing on now has houses on it. What was an easy drive now had traffic signals all along and takes three times the duration. Your house, from its prominent location, is now worth 10 times what you paid for it. Such is life.

[Del Prado]

"Guys and Girls please also note that 160kts to 4nm etc is an ATC request, if you accept then you have to fly it."

Actually it's an instruction not a request.


"If you cannot for any reason tell them, and tell them what speed profile, i.e. 160 to 5nm you can accept."


Absolutely. And please remember all requests to deviate from the norm should be made in good time (eg. Downwind) and not when there's some one else 2.5 miles behind you.


"Remember you are in charge of the machine not them. I know that we follow what they say usually without question, and it works well. But at the end of the day the buck stops with you."

Whilst I agree wholeheartedly with the sentiments there would have to be a valid reason. Repeated requests for non standard speeds would be noticed by the airport operator and I imagine your employer would be asked to justify any consistent non compliance.

We can't have the tail (one aircraft) wagging the dog (the entire airport operation) can we?

[back to Boeing]

If people didn't routinely do 160/4 then I would imagine the whole heathrow operation would fall to pieces. It's easily doable. However in less than ideal conditions you will sometimes be doing it with gear and flap and dragging it in. The increased angle and 160/4 is a less than ideal condition, so unless there's a strong headwind I'll be dragging it in and it'll completely negate the trial.

[Ian W]

It's a cheap attempt to "sell" the third runway to already hacked off residents - nothing more, nothing less. Looks good as a news item but has no legs - it won't live past it's "sell by" date.:ugh:

Imagegear

I agree.
The third runway will itself greatly increase the risk of hazard to London reducing safety. Adding a steeper approach to further increase risk is small bear in comparison. However, it is obvious that commercial/political goals have more attraction than safety.

[DaveReidUK]

Heathrow released some more advance information on the forthcoming trial a couple of days ago.

Among the salient points:

- Average usage of the current 3° RNAV approach is around 5 arrivals per day (Feb/Mar 2015), almost all BA and mostly A320 family aircraft

- "Broad engagement" re the trial, with positive results, has taken place with: AF, AA, DL, SR, UA

- Specific impacts of the trial to be measured are on: separation, CDAs, runway occupancy times, go-arounds, speed control, joining point, noise (the latter to be measured under the 27L approach)

- "No differences recorded" for pilots who have flown the 3.2° approach in the sim, though pilots who have not done so are "expecting significant changes to the approach speed and the ability [to] carry out a continuous descent and LP/LD approach"

- No expected change for ATC except for familiarisation with the process

- From the ground "visually the aircraft may appear slightly higher and quieter" [sic]

http://www.heathrow.com/file_source/HeathrowNoise/Static/Steeper_Approach_trial.pdf

[atakacs]

Ok not a pro here but does that 0.2’ really have a measurable impact ? Seem very minor to my untrained eyes...

[Emma Royds]

Isn't this just a test case for developing even steeper approaches that could pave the way for us seeing a small number of movements during the night? In such cases, flow rates would be small and 160 to 4 would be less of a significance.

I can't speak for others but for us at Emirates, our illustrious leader has for many years commented on the need to develop steeper approach technology to enable night time operations at Heathrow. We have seen the A318 handle the 5.5 slope at London City so it begs the question if we will ever see a A380 fly a RNAV approach, with a profile of more than 3.5 degrees.

[dkz]

Still, no answer on the wake turbulence issue. A "super" on a 3.2 degree RNAV and a min separation "heavy" with light winds :=

[DaveReidUK]

Isn't this just a test case for developing even steeper approaches that could pave the way for us seeing a small number of movements during the night?

The first part is certainly true - Heathrow have said that "we believe approaches of up to 3.5 degrees are feasible in the longer term".

I'm not aware of any connection between that and a relaxation of the Night Quota (which would need Government approval).

[NigelOnDraft]

"No differences recorded" for pilots who have flown the 3.2° approach in the simSums it up really... Sim is a great academic tool, but poorly reflects reality e.g. shifting winds, ATHR mind of it's own. It's also why the ATC view of "you must tell us if you cannot do 165 to 4" early on is impractical.

It's only once on the approach, EAI? winds? that how feasible 160 to 4 comes, if you want the minimum noise technique. 160 to 4 is easy - just drop the gear when slowed from 180, with F2 and up comes the power.

As those familiar with the A320 series know, the quietest / most fuel saving approach is actually about 1/2 dot low at 180K F1. When ATC ask for 160 to 4, reduce V/S take F2, decelerate and inc the F2 "balloon" you can remain at idle all the way to ~1100R. That is feasible on a VMC ILS/MLS.

On an RNAV it is not feasible really - you need to fly the correct vertical profile, so the 180K to 160K decal is a challenge at 3deg if you want to be quiet during the 160K portion.

But as others have pointed out, the trial has likely already been written up as a success, and winter RNAV 3.2deg is likely lower than ILS 3deg anyway :D

[deptrai]

this paper is a relatively thorough theoretical discussion of various aspects of a 3.2 ILS slope in Frankfurt:

https://www.ff.tu-berlin.de/fileadmin/fg198/100929_AIAC14_Paper_6_00_Koenig_Schubert.pdf

The theoretically predicted noise benefits due to a 3.2° glide slope angle were confirmed in the full flight simulator study. However, the benefits were slightly smaller than expected. Only direct noise measurements from real flight operation will provide the final proof.

the subsequent 2 year trial in Frankfurt showed a clear reduction in the maximum sound level ranging between 0.5 and 1.5 dB (A) depending on the monitoring station and the aircraft type.

0.5 to 1.5 dB reduction isn't a whole lot, but it's more than what newer aircraft/engines have contributed for arrivals over the last decade, as a lot of the noise is from the airframe. Evidence also suggests the noise footprint area is reduced by about 5-10% for every 0.25 degree increase in glide slope (...and I can hear some people asking "so where will this end?", but due to aircraft certification limitations I think that's not a realistic debate now).

[pappabagge]

The document issued by Heathrow [http://www.heathrow.com/file_source/HeathrowNoise/Static/Steeper_Approach_trial.pdf] is a very poorly-scribed piece of work indeed, peppered with errors in both grammar and syntax, and does not to my mind represent the (hopefully) more clear thinking behind the project. It's a shame that Heathrow could not apparently run to the expense of having a literate person proof-read the document prior to publishing it. End of rant - back to mowing the grass.

[macdo]

3.2 is not a big issue, but cda + 160 to 4 and F3 can give you problems in light or tailwinds. Easy option, ditch F3 and land like Airbus intended FFull!

[back to Boeing]

And that completely negates the point of the trial. You'll be significant power against drag.

Of course the 3.2 isn't a major issue. The A318 has demonstrated it can fly a 7.5 degree slope. The issue is the 3.2 plus the 160/4 means crew will increase drag earlier (to maintain the speed required) and thus increase the noise levels.

[RAT 5]

It depends on who you are trying to protect from noise. I've visited friends by LHR, AMS & CDG. I've seen some horrendous drag in level approaches. I've watched gear down at ridiculous distances from Rwy. 160 - 4nm is great, but if you start from level 2000' it is useless to those who live at 7nm. If you make a 3.0 slope from 4000' with idle thrust it benefits an enormous number of people. If you make 3.2 slope from 2000' it benefits nobody extra. You could easily make a CDA from 6000' at LHR & everywhere else. It might be curved, who cares. It's a doddle in todays a/c. Idle thrust from 6000', 160 - 4nm, easy: less noise less fuel, job done. Tinkering with minutiae, waste of time.
In B732, no LNAV no VNAV, only DME; if you spooled up before OM you bought the beers that night. CDA from FL330. That was 1980. Come on guys, get with it! The politicians are muppets about this. Don't get sucked into it. OK, I agree, LHR/LGW/LTN/STN do make an interesting Rubics cube for ATC SID's & STAR's but if they start with the identifying the correct problem they might find the best solution. 3.2 glide slope is not a solution for anything.
I flew out of a noise sensitive airport and its ILS platform was a daft 2000'. At night they radar you to a 3000' glide slope intercept fro noise reasons. They didn't publish this, so you planned for a CDA to 2000'. If you were on a 180 trun to finals you now had to extend and make noise or use V/S. The point is they raised the platform to reduce noise, not steepen it.

[stilton]

The A318 is able to fly a very steep slope into LCY with significant modifications to the flight control system.


This is not a standard AB set up.

[OldLurker]

Many jet types fly into LCY with its 5.5° glideslope, notably BAe 146/Avro RJ and various Embraers, besides the bizjets – though I believe A318 is the biggest. Their pilots seem to survive.
LCY is an extreme example, of course, compared to a change from 3° to 3.2° at LHR.

[derrick holmes]

What is the big deal?

[BalusKaptan]

Oh? Not necessarily a problem but very demanding. Frequently arrived BOM at 330T+ landing weight and that leaves no margin for error.
Also often run into problems in continental US were standard operation is 767/330 type at the max but I'm landing at 330T+ with absolutely no comprehension by ATC as to the physics of a heavy aircraft. I do my best to keep my cool but really, some of the controllers just are not in the real world.

[DaveReidUK]

Some more background on FRA's experience with 3.2° approaches:

http://icana.umwelthaus.org/fileadmin/files/Icana/Dokumentation_ICANA_2013_Teil_2.pdf (Pages 107-129)

https://www.youtube.com/watch?v=0n9YiL-vXkY

Possibly a bit more relevant than trying to draw parallels with LCY. :O

[Boxkite Montgolfier]

As a resident subject to LHR westerly approach paths who has neither a cheap house,an insensitive ear nor an eyesight problem may I take issue with some of the unsympathetic comments regarding this trial.
I watch many approaches into Heathrow and generally am appalled at the variance of gear deployment and occasional glide path divergence within normal operations. There are some operators who clearly adhere to the requirement for a stabilised, gear deployed approach at a ht of 3000+.
Any 'Trial' that seeks to alleviate noise without invoking flight safety issues is to be welcomed. Those that protest the difficulty of a 3.2 degree slope I would hope operate other than at Heathrow or on less demanding equipment! They certainly would struggle significantly at some of the global airports mentioned.
I would mention a familiarity over 30 years of heavy jet operations worldwide and naturally discount ATC induced speed,sequencing, traffic and abnormal requirements.

[wiggy]

There are some operators who clearly adhere to the requirement for a stabilised, gear deployed approach at a ht of 3000+.

:confused:

Is that said in jest or am I misunderstanding the context?

That's certainly not our requirement, not even into LHR, not even on a heavy....never has been AFAIK.

[Trinity 09L]

As a resident under the easterly arrivals, 30% of arrivals, and little alteration, HAL have not placed any noise meters, they are all under the 27(maybe even 27L only) so the results are skewed.:=

[DaveReidUK]

they are all under the 27 (maybe even 27L only)Correct.

Two mobile noise monitors have been deployed under the 27L approach, at Mogden Sewage Treatment Works in Isleworth and the Royal Mid-Surrey Golf Club at Old Deer Park, Richmond, supplemented by the existing fixed monitor site adjacent to Hounslow Heath (normally used to measure 09R departure noise levels).

Heathrow have said that also hope to site an additional mobile monitor farther away from the airport in order to measure noise earlier on the 27L approach, but no location has yet been announced.

[ShotOne]

Not in jest wiggy. I know of two operators who require full configuration by 2500'.

..and box kite, nobody's "protesting the difficulty" just pointing out that in many cases it'll need drag earlier so it's not going to make the world any quieter.

[dkz]

That would eventually cost the airport a lot more in increased separation, more CO2 (holdings/go arounds) ...

[good egg]

Just out of interest has anyone studied vortices at steep approach airports?

[Gonzo]

dkz,

Still, no answer on the wake turbulence issue. A "super" on a 3.2 degree RNAV and a min separation "heavy" with light winds :=

Who have you asked?

[underfire]

We have, and are currently studying wake turbulence.

Basically, more flap equals more turbulence.

I really doubt that one would put an A380 on the 3.2 GPA....

[DaveReidUK]

I really doubt that one would put an A380 on the 3.2 GPA.... BA did exactly that in an earlier trial, in May of this year.

[underfire]

Sorry, meant to follow on 3 below an A380 on 3.2

[DaveReidUK]

Sorry, meant to follow on 3 below an A380 on 3.2Well somebody would have been behind those trial steep approaches, with the trailing aircraft obviously at 3°, but whether they were at the standard or increased separation (or maybe used the parallel runway to avoid wake issues), I haven't been able to find out.

Where's Gonzo when you need him?

[stuckgear]

I live near Heathrow and bought my house in 1986. I got copies of the official approach and departure tracks (I still have the dye-line print) to make sure I was away from the flight paths. An ATC told me they were very unlikely to change. In 1986 there were very few flights after 8.30 pm at night. Since that time the departure tracks have changed and the number of flights has increased by 50%. Most of the extra flights are in the early morning and late into the night.

When I bought my house aircraft noise (and pollution related to the airport) was not an issue for me.

Please can we drop the argument that says 'you bought there so it is your fault'? When I bought it was reasonable to assume I would not be bothered by airport noise. I am. The air was clean. Now it is not.

So you were fine with the noise from Stage II aircraft, that belched emissions and noise, but not with later generation engines?

London air was not clean in the 80's, the 90's or the 70's, however it is cleaner now https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/388195/Emissions_of_air_pollutants_statistical_release_2014.pdf

[safetypee]

RAE Bedford conducted extensive noise trials 1975-85 which showed significant benefits with increasing approach angle. IIRC the BAe146/Avro RJ AFM has a table of angle vs noise for the full landing config.
One aspect of noise was the aircraft configuration. Engine noise reduction was generally understood, but the effect of the airframe less so; this was studied with overflight tests and a few Tristar ‘under-flights’ below a large noise monitor suspended from a helicopter.

Bedford also studied wake vortex, but I don’t recall any specific trials with steep approach, or any concerns that any change of approach path would significantly affect the wake.
I recall a study of the LHR 27R ‘famed’ vortex from a hanger (bakery?) with a SW wind which affected aircraft on short finals.

There were also operational studies at LHR with split operations where ‘STOL’ (steep approach) capable aircraft would land long, >3,500ft from a steep approach (4.5 deg), with heavy traffic on a normal, or slightly elevated approach. The different approach paths provided wake separation such that normal runway capacity limit spacing could be used for all types. Guidance was with ILS/MLS and PAPI.
These studies were revisited with the advent of the BAe146 at LCY, but not pursued as only a few aircraft were then STOL capable and even fewer operated at LHR. The situation and balance of traffic may now have changed enough to reconsider.

There should little or no concerns about aircraft operation or wake vortex from the LHR trials providing there is no need to change from the normal landing configuration; the noise benefits from 3.2 deg would be most noticeable at distant locations.

[RAT 5]

The object of reducing noise on approach, IMHOm is to reduce the noise effect to the highest number of people. I still suggest that this can better be achieved by starting at higher platform height rather than a steeper approach from a lower height. Given ATC's perquisite to control a/c so they intercept from below this can lead to some pilots dragging it in. Leaving a STAR (IAF) fix from 6000' on a continuous descent, possibly with LOC & G.S. intercept close together at 10nm, with gear down no earlier than 5nm, would create a low noise foot-print. This is what we did on very basic B732 with no radar; so surely in today's wizz-bang all bells & whistles a/c it should be a doddle. Tinkering with the last 6-8nm seems a sticking plaster on a more serious problem.

[aox]

I live a few miles from Southampton Airport.

If a similar trial was happening here, I just calculated the aircraft would be about 90 feet higher overhead and thus 0.50dB quieter. I don't think any of the local residents would notice, not even me who is used to looking up at aircraft.

I gather the numbers are quite close to the natural glide angle for some jets, hence the mention of CDA. More drag and power is going to have to happen in the latter part of the approach though, and there will be limits to how close that transition can be brought.

So the trial will have negligible effect on the people most affected.

I don't think the human ear and brain can notice a 0.5 dB difference in a few seconds let alone a few days. Like guessing the weight of two cakes a few grams different. What is the PR point of promising an improvement that will turn out to be imperceptible?

I thought I would check my assertion about levels. I found discussion on a hifi type forum, where they proposed tests with 1 dB plus or minus or zero change in mid piece. Some discussion of which music or just pink noise. Someone said that 0.5 to 3 dB is said to be undetectable. Nobody actually polled any results. The discussion closed with someone talking of reading about a test with MRI scanning of people told to imagine they were sampling an expensive wine, and there was raised activity in parts of the brain that sense pleasantness. Placebo effect.

So the people who suggest this trial has already been deemed a success may well be right. But maybe it just depends on telling enough people.

[scudpilot]

Chaps,


I live in Sandhurst Berkshire, where I moved in 94, after growing up in Hounslow, between (what was then) 28L and 28R approaches.
Aircraft noise does not bother me in the slightest, but local Facebook groups are going all "nimbyish" over it.
Am I likely to really see ANY difference when I wake up on 14th September?

[DaveReidUK]

Am I likely to really see ANY difference when I wake up on 14th September?

The official line is that "visually the aircraft may appear slightly higher and quieter (1-2dB on average)".

See link in post #60.

Oh, and the trial doesn't start until 17th September.

[Shaka Zulu]

Well somebody would have been behind those trial steep approaches, with the trailing aircraft obviously at 3°, but whether they were at the standard or increased separation (or maybe used the parallel runway to avoid wake issues), I haven't been able to find out.

Where's Gonzo when you need him?

Standard separation and it was a trial for the night jet ban slots. Eg. Land before 0602LT.

On our fleet and in our airline the aim is a CDA.
For our fleet this works well with Gear Down at 2000ft. 160kts-4Miles. stable around 1100ft.

VA is particularly bad at dragging their way in over London with gear down. Noisey in Barnes!!

[DaveReidUK]

Standard separation and it was a trial for the night jet ban slots. Eg. Land before 0602LT.

OK, so presumably the BAW12/26/56 arrivals then, as they are the only A380 landings before 0600.

Any idea of the dates involved?

[victor tango]

just in case you missed it and reviving

thread


BBC NEWS | UK | UK Politics | Heathrow expansion plans unveiled (http://news.bbc.co.uk/1/hi/uk_politics/7106524.stm)

[victor tango]

Heathrow's new angle to win over neighbours: Planes to use a steeper landing as they descend in bid to cut noise levels
Heathrow Airport announces plans for steeper landing approach for planes
Planes currently descend at an angle of three degrees on final approach
From September 14, angle of 3.2 degrees will be introduced on a trial basis
Measure introduced in a bid to cut noise levels for west London residents
By EMMA GLANFIELD FOR MAILONLINE
PUBLISHED: 05:28, 11 August 2015 | UPDATED: 08:45, 11 August 2015

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Heathrow Airport has announced plans to introduce a steeper approach for planes coming in to land in a bid to cut noise levels.
Airplanes at Europe's busiest airport currently descend at an angle of three degrees on their final approach.
However, from September 14, an angle of 3.2 degrees will be introduced on a trial basis until mid-March next year.
The measure is part of 10 steps being trialled at the west London airport in a bid to improve noise levels for residents.
Heathrow Airport has announced plans to introduce a steeper landing approach in a bid to cut noise levels in west London. From September, an angle of 3.2 degrees will be introduced over the current three-degree angle
+3
Heathrow Airport has announced plans to introduce a steeper landing approach in a bid to cut noise levels in west London. From September, an angle of 3.2 degrees will be introduced over the current three-degree angle
'The steeper the angle, the less time an aircraft spends at low altitudes, which means that fewer people should be affected by higher levels of noise,' airport authorities explained in a briefing document.
'The trial will assess the operational and noise implications of slightly steeper approaches.'
The international standard approach for most airports in the world is set at three degrees, except for obstacle clearance - such as buildings or mountains.
Officials at London's Heathrow believe a steeper angle is possible and will lead to quieter approaches to the airport.
If adopted permanently, Heathrow will become the only airport in the UK to introduce such measures. It comes after a similar procedure was introduced at Frankfurt Airport in Germany.
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Other noise-reducing measures being implemented at Heathrow include allowing fewer plans to land and take off after 11pm.
Heathrow said it is also trying to encourage airlines to use 'modern, quieter planes' and has adopted noise insulation schemes around the airport.
Matt Gorman, director of sustainability and environment at the airport, said: 'Heathrow has changed, and taken a new approach to addressing our impacts on communities, including when it comes to noise.
'Our blueprint to cut aircraft noise has been driven by feedback from local communities.
'Its role is to challenge the industry to think innovatively about ways to reduce noise.
Heathrow Airport released this noise contour graphic to show how noise levels have reduced since 2011
+3
Heathrow Airport released this noise contour graphic to show how noise levels have reduced since 2011
Officials at London's Heathrow believe a steeper angle is possible and will lead to quieter approaches to the airport. Mobile noise monitors have been specially deployed for the duration of the trial, which ends next March
+3
Officials at London's Heathrow believe a steeper angle is possible and will lead to quieter approaches to the airport. Mobile noise monitors have been specially deployed for the duration of the trial, which ends next March
'Steeper approaches are just one step in the right direction, and along with other quieter operating procedures and incentives to bring quieter aircraft into operation, will ensure fewer people are affected by noise, even with an expanded airport.'
However, John Stewart, chairman of Hacan – a group which opposes expansion of Heathrow – said the new measures would offer little improvement.
He told The Times: ‘Increasing the angle will have some impact, and the cumulative effect of the plans set out in the blueprint will be felt on the ground, but the effect will be very small.’
Mobile noise monitors have been specially deployed for the duration of the trial and a report will be issued at the end to summarise the findings.
It comes as the Government considers whether to approve a third runway at Heathrow or expand air capacity in southeast England at another airport such as London Gatwick. A decision is expected by the end of the year.
The issue has proved highly controversial, drawing opposition from figures including London Mayor Boris Johnson, partly over concerns about noise in the densely populated area of west London over which many Heathrow flights take off and land.
A commission looking into the issue published a report last month strongly backing a third runway at Heathrow.

Read more:
Heathrow outlines new approach to cut noise | The Times


Read more: Heathrow planes to use a steeper landing as they descend to cut noise levels | Daily Mail Online (http://www.dailymail.co.uk/news/article-3193195/Heathrow-s-new-angle-win-neighbours-Planes-use-steeper-landing-descend-bid-cut-noise-levels.html#ixzz3m3dgSvAL)
Follow us: @MailOnline on Twitter | DailyMail on Facebook

[DaveReidUK]

However, from September 14, an angle of 3.2 degrees will be introduced on a trial basis until mid-March next year.

The trial was in fact due to start yesterday (17th) with the new AIRAC, though Heathrow initially put out an incorrect press release with the 14/9 start date.

[HEATHROW DIRECTOR]

<<In 1986 there were very few flights after 8.30 pm at night. >>

I had been working there for 14 years by then and I do not recall "very few flights after 8.30pm".

[stuckgear]

<<In 1986 there were very few flights after 8.30 pm at night. >>

I had been working there for 14 years by then and I do not recall "very few flights after 8.30pm".

And in 1986, BAC1-11's 707's, DC-8, 727 were in common operation.

[DIA74]

As pax, I experienced a steeper approach into LHR on !8 Sept. Ended in a "robust" landing and fairly fierce breaking. Do not know wind conditions - light storms and turbulence over southern counties. Frequent "robust" landings will not enhance LHR's case with pax. Sadly not likely to appease resident groups or politicians with their own agenda.

[DaveReidUK]

As pax, I experienced a steeper approach into LHR on 18 Sept.

Out of interest, what was the airline/flight number?

[Fanatic]

DIA74 Sorry I'm lost there.
Ended in a "robust" landing and fairly fierce breaking.
What broke?
What is the connection between a 7% steeper approach and a robust landing?
How did you know it was a steeper approach? Did the Nigel announce it or could you see the difference? I have to admit flying as a pax into Malaga RWY 13 I can't feel nor see any real difference to RWY 31.
As for robust landings - yes they happen! Anywhere.

As a pilot, flying a steeper approach, even 0.2 deg I always err on the safer side and configure earlier to avoid any FDM alerts. More drag = more aerodynamic noise and more engine noise. Pointless.

[Calmcavok]

For those observing different operators' application of configuration/stabilisation in a B77W at or close to MLW full configuration is required to achieve 160/4. So for their may be a slight improvement with the 3.2. Though not on a lower than ISA day!

[Bigbux]

Hi aox

any chance you could pm me your calcs?

I don't want to challenge them online or anything - its just that I did an OU Course many moons ago and sound propagation & attenuation - including airfield footprints, were a significant part of the syllabus.

thanks

[aox]

Not sure it needs a PM of details

At any given point on the approach path the aircraft on a 3.2 degree slope will be about 6% higher than the 3 degree slope

Sound attenuates with distance squared, measured as 20 log (r2/r1) decibels, where r2/r1 is the ratio of the distances, in this case half a decibel

That will apply to below the flight path; for places a bit off to the sides then the proportionate change in distance will be less.

[DaveReidUK]

Sound attenuates with distance squared, measured as 20 log (r2/r1) decibels, where r2/r1 is the ratio of the distances, in this case half a decibel

As a general rule, that's true. Whether it's the net effect here depends on all other things being equal.

The nub of this thread seems to suggest that they won't necessarily be.

[aox]

As a general rule, that's true. Whether it's the net effect here depends on all other things being equal.

The nub of this thread seems to suggest that they won't necessarily be.

Well, that's treating the sound as a point source, and non-directional.

Maybe someone can say whether they think those are too simplistic or poor assumptions. Yes it's moving, and continuous, but at any moment the sound reaching the observer has come from a specific point.

I also suggest that the greatest saving, due to 6.6% extra distance, will be where the aircraft is directly overhead. Where the observer is out at the side the increase in distance will be less. At say half a mile sideways aircraft on 3.2 and 3 degree approach angles are only about 1.5% different in distance from the observer. At one mile to the side this is 0.44%

A 1 or 2 dB difference is difficult for people to distinguish between two sounds played a few seconds apart. A few hours apart, assuming the trial starts at the beginning of one morning, only specialist instruments can compare. And locations half a mile and one mile to the side of the approach line will experience 0.12 dB and 0.04 dB differences. Utterly imperceptible. Where do the 2dB claims come from?

If the chosen angle means that aircraft are nearer to a pure glide approach and thus using less or idle power until the point of deploying more drag then yes that will be quieter, but two sounds the same level at source will not be distinguished by human ear and brain.

So are we talking about being able to use less power? Is that why prospective savings are greater?

What is a typical glide angle of these things? Has it worsened from 20 to 18 to justify a steeper angle being chosen? Will they also consider a range of slightly steeper angles for stronger winds?

[TrafficPilot]

This "steeper glideslope" nonsense won't make a jot of difference to those living anywhere near the LHR approach path. A poor attempt at a "sweetener" from those intent on building a third runway at Heathrow despite the objections from Londoners.

I moved to the East End of London in 2012 partly to try and escape the constant aircraft noise above our old house in Fulham (midway between 27L and 27R). Now it's just as bad in Walthamstow since they changed the approach paths. I have aircraft from both the BNN and LAM stacks being routed directly over our borough.

I love flying and I love aeroplanes but this third runway idea is ludicrous.

Today I joined HACAN. How ironic.

TrafficPilot

[pax britanica]

After 6 pages we can conclude that the effects of the trial are likely to be inconclusive ? At best a marginal improvement which 90% of people won't notice- plenty of ambient noise under the approaches from the east , traffic trains, lots of people etc etc .

[ImageGear]

I refer again my post 14...still well justified....:*

Imagegear

[DaveReidUK]

It's probably worth keeping an eye on Heathrow's daily operational stats at

Daily Operational data - Heathrow Operational Data (http://www.heathrowoperationaldata.com/index.php?option=com_content&view=article&id=139&Itemid=159)

which I assume will include the number of RNAV 3.2° approaches each day in addition to the other existing metrics (though the stats aren't broken down by airline or type).

Currently only showing up to 16th September (the day before the trial started).

[Smokie]

"The steeper the angle, the less time an aircraft spends at low altitudes, which means that fewer people should be affected by higher levels of noise,' airport authorities explained in a briefing document."


Bullsh1t!!!:=

[Private jet]

I do agree with the line "it won't make a difference to 95% of people" or whatever, however there are some quite defensive comments here, as if people are scared of the change and actually having to do it. I've done London ****ty (sorry City) and its really not that difficult, just a slightly bigger earlier more precise flare at the end. If a pilot can't adapt to that it's time to take up bus driving or lawn mowing.

[wiggy]

P j

Agreed.

The trial approach(s) are no steeper than many an ILS 'slope across the world, it's certainly nothing like London City. OK, a bit more care and effort might be needed to make the 1000' AAL gate but after that I don't think the end users are going to see any real difference at all...and I don't think the listening audience is going to perceive anything differently either.

[wanabee777]

Narita requests the use of the minimum flap setting conducive for a safe approach and landing to help reduce the ground level noise contours for the surrounding communities.

e.g. For a B-777 that would mean final flaps of 25 instead of the usual 30.

[wiggy]

For a B-777 that would mean final flaps of 25 instead of the usual 30.

Airport authorities worldwide, not just LHR or NRT might like a lot of things done certain ways but safety can mean non-compliance. The authorities at NRT may "require" operators to use Flap 25 but regardless of their wishes I can promise you Flap 30 does get used.

[wanabee777]

Quote:
For a B-777 that would mean final flaps of 25 instead of the usual 30. Airport authorities worldwide, not just LHR or NRT might like a lot of things done certain ways but safety can mean non-compliance. The authorities at NRT may "require" operators to use Flap 25 but regardless of their wishes I can promise you Flap 30 does get used.From Narita Jepp 20-4:

"APPROACH (Delayed Flap and Reduced Flap Setting)

(b) Use, as the final landing flap setting, the minimum certificated landing flap setting published in the approved performance information in the Airplane Flight Manual for the applicable conditions."



There is no question that the PIC makes the final decision ref "for the applicable conditions".


Again, from Narita 20-4: "The final authority to apply these procedures, however, rests on each pilot-in-command, who may use other appropriate procedures if determined to be necessary in the interest of safety."

[haughtney1]

Wannabee I operate the 777W into NRT close to MLW on a fairly regular basis and am aware of the notam, using F25 adds 7kts or so to the VREF and then unless you want to run into potential issues with hot brakes you end up having to use full reverse, making a heap of noise..but keeping the brakes cool. Or you use F30 with a corresponding reduction in brake energy. Airport authorities can promulgate what the would like for as long as they like, the reality however seldom matches the theory.

For those observing different operators' application of configuration/stabilisation in a B77W at or close to MLW full configuration is required to achieve 160/4. So for their may be a slight improvement with the 3.2. Though not on a lower than ISA day!

You can use F25 to comply with 160/4 then configure to F30 at about 5 miles, and be fully stable at VREF + 5 at 1200 AGL, I did it today in ISA + 20 conditions, its no drama at all, but it is a noisy way to do it, 170/5 works waaaay better at F15.

[Gove N.T.]

Travelling through Putney, I noticed no difference ( not that I would I suppose ) but what I did notice was that planes overhead were almost silent compared with the noise of road traffic. The MP for the area, Justine Greening, must have had super selective hearing to say that she was deafened by airplane noise.
We live on the 09R flight path where A380 and 787 pass overhead at around 1800ft and it is possible to continue an almost normal conversation. Impossible with BA747 and 777 etc,

[Max Angle]

Done quite a few of these now in 320s and 319s and it is, as you might expect, a complete non event, started slowing up a fraction earlier in the 319 but that's about it. Whether it makes any difference to those on the ground is a different matter of course, suspect not.

[BBK]

I think some people have forgotten that this is a trial, although not the last few comments to be fair, so let's see what the results show when the trial is complete. As someone who used to conduct trials work one might have an idea of the expected results but sometimes the actual data confounds this. It's called having an open mind!

The increase in angle, I should imagine, is a non event as max angle (appropriate name:O) has said. Perhaps gear and landing flap a tad earlier or even "non standard flap 20" on the 744 ie flap and delayed gear. I guess in calm/ tail wind conditions then one might be at thrust idle for a greater duration but that should help all other factors being the same.

Will it make a difference that is discernible to the public under the flight path? Maybe not but I believe the trial is more than just about a steeper approach for noise issues. The subject of speed control with respect to time based separation will be addressed I'm sure. Just my two penn'orth.

[GeeRam]

Travelling through Putney, I noticed no difference ( not that I would I suppose ) but what I did notice was that planes overhead were almost silent compared with the noise of road traffic. The MP for the area, Justine Greening, must have had super selective hearing to say that she was deafened by airplane noise.

Having lived under/adjacent to Heathrow's runways for 50 years I just get infuriated by some of these frankly stupid people complaining about noise these days - it's almost insignificant now compared with the 60's/70's/80's.

They just have an alternative agenda irrespective of the actual facts :ugh::mad:

[RAT 5]

It's a human factors issue and has been known about for decades. You live on a busy road with lorries/motorbikes etc. thundering past, and as you sit in the back garden, not being able to see the trucks/etc, you filter out that regular, been there for years, ground noise. You can't do anything about it.
As you sit in your back garden a jet rumbles over head. You look at it, focus your eyes & ears on it and think how noisy it is. You grab the phone and complain, because you can. The politicians are mambying to a small minority. Years ago, west of LGW, there was a known local, who sat in his garden with binoculars, db meter and telephone to hand. There are just the same sort at all major airports. Some have more clout than others, and a louder voice in the relevant ears, but it's the same science and same problem as else where. It's a NIMBY issue. This, oh my gawd, steeper approach shock horror BS is just that. It won't solve the root problem, if there is one. Let's first identify the real problem and then design a solution, not suck it and see trials. That's the politician's answer, not the scientists.
But perhaps that is what is really going on; a political fudge to be seen to be doing something and then hide behind the report that will take yonks to be published; yawn, but clever.

[DaveReidUK]

It's probably worth keeping an eye on Heathrow's daily operational stats at

Daily Operational data - Heathrow Operational Data (http://www.heathrowoperationaldata.com/index.php?option=com_content&view=article&id=139&Itemid=159)

which I assume will include the number of RNAV 3.2° approaches each day in addition to the other existing metrics (though the stats aren't broken down by airline or type).

Currently only showing up to 16th September (the day before the trial started).

Well a week on from the start of the trial and no sign of any movement stats at all for the last 8 days, so there's still no indication as to whether the figures when published will document the number of 3.2° approaches made.

Having said that, a quick-and-dirty analysis of landings last Friday (18th) on 27L (the only runway that's being noise-monitored) would suggest that around a dozen approaches were at or above 2500' AMSL at 7 DME, compared to only a couple on the Tuesday before the trial start (15th).

Of course that doesn't necessarily mean those arrivals were flying the 3.2° RNAV approach, they could have been high for any number of other reasons. No doubt we'll be told in due course.

[Airbus Unplugged]

IMHO this is nothing to do with noise, it's a marginal gains thing.

More time spent at idle thrust, 1000' to TD slightly shorter, so 2 pints less fuel each approach.

1 aeroplane not much, 100 aeroplanes quite a lot, 1000 aeroplanes - departmental greeny wonk gets pat on the back for his lovely spreadsheet, and bonuses all round (the office).

[zkdli]

airbus uplugged could be right, this could also be about stabilisation criteria at 1,000 and four DME!

[DaveReidUK]

this could also be about stabilisation criteria at 1,000 and four DME!

Yes, monitoring speed control, (un)stabilised approaches, go-arounds, etc is one of the stated purposes of the trial.

See post #53.

[DaveReidUK]

It's probably worth keeping an eye on Heathrow's daily operational stats at

Daily Operational data - Heathrow Operational Data (http://www.heathrowoperationaldata.com/index.php?option=com_content&view=article&id=139&Itemid=159)

which I assume will include the number of RNAV 3.2° approaches each day in addition to the other existing metrics (though the stats aren't broken down by airline or type).

Currently only showing up to 16th September (the day before the trial started).

Stats are now up on Heathrow's website for the period covering the first 10 days of the trial.

Disappointingly, they don't contain any reference whatsoever to the numbers of arrivals performing 3.2° approaches.

Latest announcement on trial participation states that "a large number of airlines that have the necessary standard of navigational equipment for this approach are expected to take part".

[Max Angle]

Disappointingly, they don't contain any reference whatsoever to the numbers of arrivals performing 3.2° approaches.Not great I suspect judging by my own example and the number of people you hear requesting the RNAV "Y" approach, suspect that most people can't really be a***d with it.

[Airbus Unplugged]

Asked a few times in the last couple of days.

Despite minima +300' or VFR conditions, requests denied due separation requirements.

Not many data points for the trial then.

[Gonzo]

We're getting plenty, more than expected, and enough for the purposes of the trial. We're trying to enlarge the sample in terms of airlines and types, which is why if you offer it may get refused, along with the reasons already cited.

[DaveReidUK]

Are requests for RNAV Y approaches more likely to be approved when the landing runway is 27L? AFAIK, that's the only approach being noise-monitored during the trial (though of course that's only one of the objectives).

And any idea why the numbers aren't being published in the daily stats? Those normally appear at least a week in arrears, so presumably it wouldn't be difficult to collate the data in that time.

[underfire]

Measurements carried out by the German Aerospace Centre (DLR) at seven monitoring stations operated by Fraport and the Environment and Community Centre (UNH) showed a clear reduction in the maximum sound level ranging between 0.5 and 1.5 dB (A) depending on the monitoring station and the aircraft type. The measurements were conducted over the entire period of the trial operations.

Between October 2012 and December 2014, about 145,000 aircraft landed on runway northwest using the increased glide angle, representing 71 percent of all landings. During this time, the new procedure neither caused a higher number of go-arounds nor any delays for arriving aircraft.

The additional instrument landing system (ILS) and the required relocation of the glide path transmitter cost EUR 3.2 million. The operating costs amount to EUR 300,000 per year.

Not certain a 'clear' reduction of 0.5 to 1.5 is even perceptible to humans, and a significant cost...
a correlation was not done with the new aircraft coming on line in the 2 year timeframe, many of which are much quieter...

https://www.dfs.de/dfs_homepage/en/Press/Press%20releases/2014/19.12.2014.-%20Active%20noise%20protection/

EDIT: I understand the 3.2 is an option for Gatwick?

[Cough]

Flip side, I've asked for it 5 times over the last two weeks...

Approved every time.

Even managed to stop the Airbus flying level at 3520' too!!!