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Final approach speeds

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Final approach speeds

Old 17th Nov 2006, 08:23
  #101 (permalink)  
 
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Exclamation

I don't think it's fair to say that we've lost interest. Just that this forum is all too vulnerable to hearing the same characters banging on all the time.

Mode S transmits the instananeous IAS, heading, selected altitude and aircraft groundspeed/track information. I hope we will have revealed that every operator/airplane combination has a different set of hoops to jump through. Many of those have flight data recorder audit trails, requiring the commander to excuse himself for this approach or that landing (if we could but remember them amongst all the others).

It's all too apparent that BA are not flavour of the month at the moment at LHR, but just like everyone else they're doing the best they can with the hand they're dealt.

Many factors lie outside the control of the pilot on the day (especially the all too frequent ground difficulties) but the individuals at the controls are not trying to be difficult. They are however all too aware that transgressing the (sometimes ridiculous) rules will result in an interview with the school bully.

If we're up against it, and you're up against it, that says to me it's time to turn round to the beancounters and say BACK OFF!

It's either that or we'll be discussing who was to blame for the big one.
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Old 17th Nov 2006, 11:28
  #102 (permalink)  
 
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160kts to 4 miles is almost impossible in the 757 when operating at shuttle weights. Factor in the anti-ice and the inevitable tailwind on base/finals whne landing on 09L then it becomes a real challenge to even get the aircraft stable.
120.4 i understand your frustrations but my priorities lie firmly in keeping the aircraft safe and getting it established and stable on the approach for what i
(and my company SOP (BA))consider to be in an appropraite position to continue to a landing. This inviarably involves reducing below 160kts at 5 miles ish. LHR runway capacity doesn't even figure in my thought process. Although, i might add i will do my best to avoid sending anyone around..which i haven't in 10 years of flying at LHR.

My company SOP states that we should be stable at 1000'ATRE and must be stable by 500'ARTE. The final flap and speed reduction must be taken at 1500'ARTE. This is quite plainly at odds with what you ask.

FWIW 160kts to 4 miles is easier in the 767 as you obviously haven't got as much speed to lose.
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Old 17th Nov 2006, 11:58
  #103 (permalink)  
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3 greens

Quite understand your position. For some time now I have been giving B757s 160 to 5d in recognition that 160kts to 4 is asking them to lie. It is quite noticeable that the B76s find it much easier.

The trouble is that in keeping your aircraft safe you are likely to be introducing a wake vortex issue for the B73s, A320s etc. behind you. That puts them in an unsafe situation and makes me illegal; Can't be right can it? This conflict of interests must be addressed.

.4
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Old 17th Nov 2006, 15:39
  #104 (permalink)  
 
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.4, quite right...something needs to be done as it is p155ing both sides off at the moment. Quite how one enacts such change however is perhaps why we continue with this practise
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Old 17th Nov 2006, 16:35
  #105 (permalink)  
 
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3 Greens -

Small point - If you are BA then I'm sure you know its 1000' RA. Check FCO 2838. Totally agree with the point that agreements have to be adheared to.
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Old 17th Nov 2006, 16:46
  #106 (permalink)  
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Another for 3Greens -
The final flap and speed reduction must be taken at 1500'ARTE.
- since 4D equates to 1410'ARTE, 'taking land flap and speed reduction' AT 1500'ARTE is no issue, unless you are saying you must be 'on speed' AT 1500'ARTE?

I still think you Nigels should ask one of your 'wunderkind' how you are supposed to do it - and get the answer in writing
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Old 17th Nov 2006, 19:39
  #107 (permalink)  

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BOAC - as an ex-Nigel you may expect that they're rather busy replying to a deluge of e-mails from the current Nigels on another topic...
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Old 18th Nov 2006, 16:36
  #108 (permalink)  
 
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Originally Posted by IcePack View Post
Bit of tail waging the dog here.
Not all pilots are of the same caliber.
If a pilot feels safer slowing down as per company SOP's then so be it flight safety is paramount.
Only excuse to not telling ATC is because you can't get a word in edgways.
I totally agree.

Quoting from 120.4 earlier...

"The UK based one was indicating 145kts at 6nm from touchdown having been given 160kts to 4."

With my simple calculator, based on a 25kt. headwind, the chap at 145 kts two miles earlier than instructed "lost 6.5 seconds" in the 2 miles. If there had been less headwind then the "lost" time would have been less.

120.4, are you under so much pressure to reduce the spacing that it may affect safety?

Having flown the Trident, 757, 767, and 777 into Heathrow for years I agree with the earlier post regarding the 757. There is nothing worse than sitting on the edge of your seat (in cloud on the approach), anticing on watching the IAS dribble back to V-ref +5. The old brain database remembers such approaches and suggests never again. The next time, perhaps with a junior copilot you suggest slowing up just that little bit ahead of the 4,5 or 6 miles (whatever it maybe) but struggle to get a word in on the radio.

We're only human after all. We've all sat on the edge of our seats, luckily most never actually fall off!

If the pressure, 120.4, is placed on your shoulders to reduce spacing why, with safety paramount, do the powers that be not look at parallel landings, surely that would help your wake problem.
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Old 18th Nov 2006, 19:01
  #109 (permalink)  
 
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Woodpecker -

I am sure 120.4 will come up with a definitive answer (I am just a TMA area controller). It depends what you call affecting safety. As an Area controller, I am allowed to use 3 miles separation in the LTMA instead of the usual 5 miles, because of congestion. The heathrow directors are allowed to take that down to 2.5 miles within certain criteria.

That 2.5 miles is an absolute minimum. If 120.4 breaks that because someone is not flying as they have been instructed, he will be suspended.

This will cause more delays as we are tightly manned as it is. When busy and all positions are open, we cannot afford to lose one ATCO, otherwise we start running out of the legal time we can work between breaks.

The 2.5 miles is because Heathrow is such a busy airport. If airlines want it pushed up to 3 mile spacing so that they can have a plus or minus 25kt leeway on speeds, then this will mean that AC will always hold for more than 10 minutes in all but the queitest or times. I do not think the airline bosses will be happy with that.

Parallel landings are used, first thing in the morning, to ensure that delays are not allowed to build (if we start off with holding at 0630, it can take several hours to catch up - the airport is running at such a high capacity)

Using parallel runways during the day as a standard way of operating, would not work with ground movements and departures thrown into the mix. I am sure 120.4 would be able to elaborate a little more on that one.

What I am getting from this thread, more than anything else, is that 120.4 would like to be told if you cannot comply with the speed instruction, for whatever reason (slippery A/C, company SOPs). If he does not get told, then how can he adjust the guy behind or ahead to maintain the separation?? Heathrow controllers are not Gods (though some like to think it ), they cannot know what you are going to do by reading your mind.

If their is a specific company policy regarding certain A/C, then let ATC know at OPs level. Once known it is fairly easily adjusted for, in the same way that heavys/mediums/lights need different spacing.
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Old 18th Nov 2006, 23:06
  #110 (permalink)  
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Woodpecker

Thanks for your interest.

I haven't done the maths myself: remember, he has also been losing time whilst he has been slowing to 145 kts. Additionally, although we "discount" spacing drift inside 4nm, as the following traffic would be maintaining 160kts until it gets to 4d the time interval between them continues to reduce after the heavy gets inside 4nm. Who knows where that becomes unsafe? We don't.

In this particular case I instructed the following traffic to go around when its spacing behind the heavy was 4nm; it should have been (and had been!) 5nm. Fortunately, although the Tower controller initially indicated that the departure runway would not be available for the following traffic, they managed to change their plan to suit me and shortly after the traffic had commenced its climb I was able to offer it a late visual switch to 27L.

Please, lets be clear here: I applied the minimum legal spacing for that aircraft pair because that is the demand of the airline community; that spacing was established some 7 or 8 miles previously and I applied common speeds to maintain it. If we don't apply minimum spacing when ever we can then then Heathrow's already oversubscribed capacity will be diminished.

Heathrow's runways are scheduled at a rediculous 98% of capacity, Frankfurt, I believe, is 90% and Paris 80%. As a point of note: Heathrow approach is deliberately flowed at 2 or 3 aircraft per hour above the anticipated landing rate so as to keep pressure on to achieve minimum spacing. Under those circumstances, traffic that is at 145kts at 6nm instead of 160kts to 4 is placing the ATCO in an illegal position, and the following traffic in a dangerous position that we are not permitted to ignor.

During the week a Heathrow colleague was suspended after traffic that had read back the correct heading took up and incorrect one and infringed separation. The ATCO was not at fault but it was a number of hours before he was re-instated and this can have significant consequences for delays.

I have absolutely no desire to, nor would I ever put aircrew in a compromising position. If our standard speeds are not working for you then we have to change them because not flying them puts us in a compromising position. This cannot be right.

Mixed-mode is being looked at now; infact I was centrally involved in the concept design. There are many issues, and politics to resolve before it can be implimented. Current rules have DfT restrictions.

Hope this helps

.4
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Old 18th Nov 2006, 23:23
  #111 (permalink)  
 
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So he started the go around and then reverted to a visual.

OK, I'm sure he did it all perfectly, but we've had the CAA all over us (the TRE's) trying to ensure go arounds particularly those not commenced from minima are flown correctly and all the appropriate checklists completed prior to the next approach.
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Old 20th Nov 2006, 20:30
  #112 (permalink)  
 
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oh for the good old days

4 dme from runway is about 1200' (maybe 1264 afe)...and being stable at 1000' afe is about right for most planes


remember the days when you would place your Marker beacon receiver on HIGH sensitivity, and put your gear and flaps down at the first beep...switch it to normal and note your time (in case gs failed)...and that was around 1500-1700 feet afe.


so perhaps 120.4 must come up with something new...slow everyone down farther out and let everyone fly stable instead of trying to cram a few more planes in per hour...the powers that be will have to come up with something other than pushing the tin.

and I know everyone on this forum wants to fly safe and the controllers want it safe too.


add the winter time need for anti ice and all that ...


jon
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Old 22nd Nov 2006, 19:09
  #113 (permalink)  
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An update, as promised...

It seems I was not the only one to have raised this issue recently with LTCC Ops. It is hoped to be an agenda item at the next Safety Partnership Meeting involving the major UK operators.

.4
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Old 24th Nov 2006, 13:45
  #114 (permalink)  
 
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Angel

Did our level best today, even caught the late turn on to the localiser with the tail wind on base. I did think it was a bit harsh to blame one of my colleagues for being left and right of the ILS though.

It was 40kts across!

Give us a break.
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Old 24th Nov 2006, 22:28
  #115 (permalink)  
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Airbus U

It was an interesting day wasn't it?

Twice this evening we had traffic back at 145kts at 6nm, both A340s and one of them caused traffic to switch to 27L. The operations department of one of the carriers gave us a slight clue to some of the speed problems but it could stand clarifying here from a driver or two.

A346s apparently use a "ground speed lock" or something? Please can a Bus-driver elaborate on that: What does this actually do, does it apply to all airbuses in all conditions or just gusty wind, is it okay to override or are you mandated to use it etc.

.4
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Old 24th Nov 2006, 22:56
  #116 (permalink)  
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I'm joining the thread late and I haven't read all of it.

However, if this is going back to the "160 to 4/170 to 5" debate, I've flown 737s and 777s as well as A320s and all are capable of anything up to and including 180 to 4 (clearly with the exception of a tailwind on finals) whilst complying with the BA SOP of stable, power up and in landing config by 1000R (I've always taken that to mean 1000' aal).

All require gear down and slightly unusual configurations to achieve it but all are well within flap and gear limitation speeds. We have to be sensitive to noise and CDAs which make us reluctant to do this, particularly at LHR (I have a friend in Richmond who invariably has the gear dropped just over her house for the A320 to achieve 160/4 in a quiet configuration).
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Old 25th Nov 2006, 07:08
  #117 (permalink)  
 
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"and all are capable of anything up to and including 180 to 4"
Thats some kind of unusual configuration in an airbus to lose 50 kts in 1nm. Please tell us more?
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Old 25th Nov 2006, 07:28
  #118 (permalink)  
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by 1000R (I've always taken that to mean 1000' aal
- and, of course, HF, your managers will receive a 'notice' of your 'misdemeanour' at 1000 radio which, may be significantly higher.

EG Inbound FNC and crossing the VOR (which is 6 minutes or more away from touchdown on R05) below around 1300' (absolutely safe) will normally trigger an 'event' due to the small ridge of land on which it sits.
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Old 25th Nov 2006, 09:39
  #119 (permalink)  
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Are there any types that can NOT fly gear down, land flap, 160kts at 4 miles and still not reduce back to approach speed by 1000 Rad Alt?

I find it hard to believe that with a headwind that this is so difficult to achieve.
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Old 25th Nov 2006, 09:49
  #120 (permalink)  
 
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BOAC- you should know better than to suggest that Flight Data Monitoring systems are used to attribute 'misdemeanours' to crews who may be operating entirely safely and appropriately in the circumstances, like the FNC approach you mention! All FDM data has to be taken in context, and used properly is an outstanding tool for highlighting areas where operational procedures may be having an impact on safety. If crews 'fear' it then its credibility suffers and its usefulness is diluted.

As an aside, 1000' RA rather than 1000' aal would be daft - that would imply that BA are happy for crews to be stable at 730' above the R09 at JER but not at 1001' aal at LGW? Surely stability criteria must refer to time to landing, not the distance to the terrain directly underneath the aircraft?

For info 120.4, the 'ground-speed lock' on modern airbusses (airbii?) is usually referred to as 'Ground Speed Mini' - mini meaning minimum rather than little.

What this system does is compare an entered value of the surface W/V as given by ATIS/TWR with the current wind and ensure that the correct groundspeed is flown, so that when the wind changes (i.e. drops) with descent, the total energy of the aircraft is not compromised and high sink rates due to shear are avoided.

Therefore GS Mini, in strong headwind conditions, often demands a higher IAS, to ensure enough knots are left if the current strong wind suddenyl drops away.

Use is very strongly recommended in windy conditions due to the protection it provides against shear, but it should never demand a lower speed than the approach speed, only higher, so using it as an excuse for flying slower than 160 to 4 is nonsense.
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