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-   -   LHR - Steeper Approaches trial 14 September 2015 (https://www.pprune.org/rumours-news/565947-lhr-steeper-approaches-trial-14-september-2015-a.html)

back to Boeing 14th Aug 2015 14:12

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 14th Aug 2015 18:58

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 15th Aug 2015 10:04

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 15th Aug 2015 10:46

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 15th Aug 2015 14:56

What is the big deal?

BalusKaptan 15th Aug 2015 15:36

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 15th Aug 2015 17:01

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

http://icana.umwelthaus.org/fileadmi...013_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 16th Aug 2015 08:54

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 16th Aug 2015 09:14


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 16th Aug 2015 14:33

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 16th Aug 2015 15:26


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 20th Aug 2015 20:55

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 21st Aug 2015 08:24

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

good egg 22nd Aug 2015 13:04

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

Gonzo 22nd Aug 2015 20:06

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 23rd Aug 2015 19:16

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 23rd Aug 2015 21:34


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 24th Aug 2015 04:08

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

DaveReidUK 24th Aug 2015 06:34


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

stuckgear 24th Aug 2015 08:17


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/upload...lease_2014.pdf


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