A340 of Iberia skids off runway in Quito

[slam_dunk]

My answer was to this question:

Correct me if I'm wrong but isn't this always true when referring to a CAT 1 ILS?

That answer still stands : NO !

sorry for the confusion

[MoodyBlue]

My answer was to this question:
Quote:
Correct me if I'm wrong but isn't this always true when referring to a CAT 1 ILS?
That answer still stands : NO !

Ah... yes, ofcourse... and in that case, you are absolutely right!

[BOAC]

So the PAPIs and the GP are not aligned? You are 'diving' a widebody and aiming at what? 2 reds/2 whites, or 3 reds/1 white? What are the TCH's at Quito for the PAPIS/GP?..............and lastly - who 'approved' this?

[Dream Land]

The G/S on a CAT1 ILS is only accurate to the DH. Anyone dispute this view?

[MoodyBlue]

So the PAPIs and the GP are not aligned?

Correct - PAPI is at the "normal" position, ILS GP antenna is much further down the rwy than normal to provide adequate terrain clearance over the ridge in front of the rwy.

You are 'diving' a widebody and aiming at what? 2 reds/2 whites, or 3 reds/1 white?

Yes, with "diving" meaning leaving the 3-deg GP at about a 4-deg flight path angle to pick up the 3-deg visual glidepath (2 white/2 red or 3 white/1 red, whatever's appropriate for your a/c type). If done correctly, the whole thing can be done without sinkrate-warnings and you'll be nicely established - even at groundspeeds in the 180-200kt region. It's kinda fun actually. By the way, all this obviously means that the minima for this approach are quite high.

What are the TCH's at Quito for the PAPIS/GP?

Haven't got the charts handy, but TCH for the PAPI is "normal", for the GP would be quite high.

..............and lastly - who 'approved' this?

Hmmm, who knows. But it's in the books and it's what "everybody" does.

[alf5071h]

Dream Land, the accuracy of the ILS is not dictated by DH. The system installation requirements will require some margin of accuracy below any operational use height.

Ref landing dist / PAPI; refer to the airport chart. The ILS threshold is displaced; this gives a LDA of 2610 m vs the runway length of 3120m. If an operator is authorised for IFR operations into Quito then the landing performance on runway 35 should match this reduced value, enabling a stabilised instrument approach and transition to the same stabilised visual approach path.
The standard requirements (ICAO?) for lighting on an instrument runway is that PAPI matches the ILS GS; if not, this deviation should be identified on the chart. I see no evidence of this. Even if the PAPI and ILS were not aligned, then the landing performance aspects should not require any duck under manoeuvre.
The ILS GS is 3.1 deg, nothing unusual; thus with appropriate performance calculations (noting tailwind) and accurate flying, then landing from a stabilised approach should not present any greater difficulty or risk than in other operations – perhaps excepting the higher grnd speed / reaction time. i.e. the margin for error in airspeed, TCH, touchdown position, spoiler / reverser deployment, is reduced.

Certificated landing performance is normally limited to 8000ft amsl. This can be extended by extrapolation usually with additional margins. Whilst most manufacturers can extrapolate for their aircraft types, the resulting performance might be uneconomic. However, IIRC Airbus conducted actual landing tests at Quito, thus normal certification rules would be expected to apply.

[MoodyBlue]

The standard requirements (ICAO?) for lighting on an instrument runway is that PAPI matches the ILS GS; if not, this deviation should be identified on the chart. I see no evidence of this.

On the chart you link to, no PAPI is shown at all. But I can tell you that the PAPI is there, and it is not aligned with the ILS GS.

The ILS threshold is displaced; this gives a LDA of 2610 m

Well, 2610m is not too much with the groundspeeds you get at an elevation of ~9200ft... runway behind you, and all that.

I guess what it all means, is that with the described technique you can use the entire runway, which is nice, but it is no longer an ILS approach. It is an ILS-letdown to a circling approach, and circling minima are used.

[alf5071h]

MB Re no PAPI indicated on the chart. I decode the “P/3.1” in the runway box, right hand column – Visual Slope, as indicating that PAPI is installed on runway 35 with an approach slope of 3.1 deg. In addition, I assume that the ‘non standard’ 3.1 deg is due to an alignment with the ILS, which previous posts indicted was above 3 deg due to distant obstacles.

Your observations and experience on-site are interesting, particularly as there is no information on the chart for crews. Is your experience with a ‘long body’ aircraft (MD11?) where a single PAPI installation may appear to be non-aligned with the ILS?
Other possibilities are that the specific PAPI installation uses a ‘tight’ beam setting and thus is very susceptible to aircraft size/configuration, or as intimated previously, less than ideal ILS GS accuracy well below DH.

The displaced ILS threshold is an interesting compromise particularly in a location where runway length is a premium. A possible alternative would have been to use an even higher GS angle ~ 3.3 deg to regain landing distance. Even at the high altitude, the steeper slope should not create any landing problems, furthermore the steeper angle would provide more precision and thus less scatter in the touchdown point; whereas the duck under / shallow approach does not.

I do not think that you should automatically assume that aiming to land short of the ILS threshold prohibits an ILS. Special techniques can be authorised for ‘difficult’ runways (post #96), but in these instances there are usually limitations or briefings to cover any additional risk. At Quito, I would expect the authority (Spain) / operator to consider the risks of deviating from the ILS approach (unstabilized), and even though this is to acquire a ‘stable’ visual approach, the speed / energy / time aspects of the higher altitude might move this to an unacceptable high risk operation. Also, - particularly; consider the effect of any tailwind.
I would expect higher ILS minima to aid the visual transition, and probably a tailwind restriction.

Ref: “Safety aspects of tailwind operations”, (2001). Also see “Running out of runway” (2005).

[TowerDog]

I operated an MD-11 into Quito many times, from both seats, day and night, for Gemini Air Cargo a few years ago.

Yeah, done the same but with 747-200s at max landing weight.
Went in there first time at night with rain and thunderstorm.
Asked the company to get a check-airman along to show me around.
They declined so I got to sort it out on my own.
(Not much of a safety culture with that lot)

The problem on the turn to final is that ya usually get the glide slope before the localizer..Doing the right thing and waiting for loc will run ya high on the g/s initially, then ya have to dive down to get it, stablilize on the g/s untill mins, right around 650 feet, then leave the g/s to dive again to catch up with the VASI or PAPI lights (forgot which), then be right on speed and in the t/d zone, grab a handful of reverse and get it stopped without cooking them brakes.
Fairly easy operation on the B-747 as it is a stable machine and really flies like a big super-cub. Never flown the MD-11 or a 340, would imagine the speeds being about the same.

It could have been some mechanical failure with the brakes or anti-skid system.....?

[Dream Land]

Thanks for info Alf.

[BOAC]

I can only hope that our experts have these sort of issues on their 'W-B' graphs for Quito and CGH, and my primary concern, like Alf, is that although I am well used to operating with PAPIs/VASIs NOT aligned with GPs, my understanding also is that IFR performance should normally be predicated on ILS touchdown point unless clearly differentiated to crews, and I am worried by the apparent 'throw-away' lines of "Oh yes, if you don't duck under and land short at CGH in a heavy 737 on a wet runway OR at Quito in a 340 you will have trouble stopping" and what this might do to the mind-set of other pilots looking at shortish runways. The analysis of these incidents/accidents MUST include the responsibility for instituting correct operating procedures and for the responsibility of crews and management to be alert to these issues and not to turn a blind eye to them for expediency and 'a bit of fun'. Does everyone have a clean sheet here?

It may be 'quite fun' and as long as it is clearly published and approved there really is no issue, but, as at CGH............................

Apart from our own skins, we accept responsibility for lots of others, and safety margins are there for a reason.

I will be relieved if I hear from any QUITO operators who have this published as SOP with warnings about LDA. It is obviously a 'special brief' airfield and I would hope at least 'Cat B' if that exists in Spain? My charts (which may well be out of date) show a 3.2deg GP and 3 deg PAPIs and a LDA of 2290m (not 2610) for (displaced) ILS touchdown with a TCH (ILS) of 59', but the quoted ILS displacement on these Jepps is only 320m so obviously there have been some changes or errors since it measures out at 510m as per the linked chart. Also obviously some sort of deviation from ILS will be required. Should this not be on the charts, rather than relying on 'visitors' having to make up their own procedure at 650'? As Alf says, why not make it a 3.5deg GP or whatever is necessary to cross the ridge at 5 safely?

MB - if, as you post, you are treating this as a 'circle-to-land', are you using 10,500/8km minima?

[bsieker]

BOAC, alf, Dream Land, TowerDog, MoodyBlue, others,

A very interesting discussion, I enjoy the tone and the kind of background information that professional pilots can supply.

Re these issues in a WB-Analysis: In CGH we did not find that "ducking under" the glide slope was a causal factor for that particular accident, although we found it interesting to note, and have been wondering how common it is/was.

The Quito/Iberia case is different in that hardly any substantial data is publicly available. When and if it becomes available we might do another analysis, and also compare it to other runway overruns, be they by A, B, MD, or F aircraft.


Cheers,
Bernd

[BOAC]

Originally Posted by bsieker

In CGH we did not find that "ducking under" the glide slope was a causal factor for that particular accident

- to correct a misunderstanding - no-one is suggesting it would be a causal factor in that accident, but a preventative factor in a lot of other successful landings! Hence the need to include it.

[GearDown&Locked]

UIO 35 photo 1
UIO 35 photo 2

[bsieker]

BOAC,

thanks for the reply.

The nature of the Why-Because-Analysis is that it only includes necessary causal factors. For analysing all the environment and conext of an accident this is a known shortcoming of the method. The other shortcoming is that it does not include dangerous situations/actions, that were not causal to the accident, although they were present, and should by all means be rectified (an example for this is the incorrectly assembled main landing gear bogie in the Concorde accident).

I'm curious about how Quito/Iberia turns out to have happened. And, of course, also Toulouse/Airbus.

[Globally]

Do we even know whether this incident was the result of a rejected takeoff, or an attempt to land? If the pictures show the reversers aren't deployed, maybe the airplane is in the takeoff roll prior to a rejected attempt.
As far as landing on runway 35. I fly 747-400s into Quito on a fairly regular basis. As part of our safety audit of this airport, I spent 3 hours in the control tower watching the overall operation. In that time period of heavy arrivals, not one airplane- big or small - landed at the ILS glideslope intercept point. All airplanes landed in the first 3,000 feet. I understand the overall need to stay on the ILS glideslope all the way to touchdown, but there are some problems with this particular runway in doing so: There is a fairly steep crown in the runway just after the ILS touchdown point, sloping downwards after the crown; All of the paint, representing the touchdown zone markings -starts on the first brick of the runway surface through the first 3,000 feet. Therefore, if you stay on the ILS glideslope, as you start your flare, the paint will disappear behind the airplane and you will have difficulty determining how much runway you're using in the flare. If you float, it would be difficult to tell when you've used so much runway in the flare that you need to go around. Furthermore, the last 3,000 feet of the runway is coated with rubber deposits and paint, becoming slick in rain, exacerbated by volcanic dust deposits on the runway. It's definitely safer to land the airplane in the first 3,000 feet as far as stopping distances are concerned. But we need to publish a procedure or techinique that allows us to perform a normal landing in the first 3,000 feet that doesn't in effect result in a "duck under" maneuver.

[supersean]

Globally,

The cockpit to tower recording played here in Quito clearly indicates that this was an accident that occurred during landing at UIO

[Globally]

Supersean. Thanks for the info.

[alf5071h]

Globally, you provide another interesting viewpoint of operations at Quito.
Viewing the situation with a wider perspective wouldn’t it be better to fix the problems at their root as opposed to finding a risky work-around, which not everyone would know of or be able to fly.
For example, remove the rubber deposits, provide a warning about volcanic ash, and if required declare the runway ‘slippery when wet’.
A more extensive solution would be to move the ILS GS origin and increase the angle.
If hazards are encountered it is everyone’s duty to report them; I suggest starting with a company safety report, then ASRS or equivalent (copy to your ops liaison at Quito and/or email this thread to them).

bsieker you explain the reasons why a ‘W-B analysis’ is limited – thanks. This is similar to a formal accident report where the absence of fact limits the conclusions as to cause and contributing aspects. An alternative approach is pure speculation; TowerDog proposes mechanical failure, but without supporting fact.
However, there is often great value in risk or hazard based speculation for preventing similar accidents; as BOAC states, providing preventative factors.
Mechanical failure is unlikely on a statistical basis (low probability but not impossible), whereas risk from human error would be high. This is not to focus on the crew; HF considerations would include all humans in the operational system, e.g. who provides and/or checks the chart information – LDA, PAPI alignment?

An example of risk based speculation might consider operational reasons for the long landing distance. We do not know where the aircraft touched down, but the discussion on duck under / unstable approach identifies with considerable risk. If operators duck under we could consider if they (operators/authority) have fully understood the risks in the manoeuvre particularly at high altitude – high GS. Or if crews duck under do they understand the risks; it is not an individual’s error (PF) it is a crew issue. Do monitoring pilots (PNF) concur with the error or do they even detect it. We could then investigate why the crew exhibit these behaviours – knowledge of the risk, training, SOPs, human issues in the organisation.
Do crews brief the specific differences in this type of operation? E.g. it is more likely that the landing weight is near limiting performance, particularly with a wet runway / tailwind. Do crew consciously decide to change the way they decelerate the aircraft or just rely on the standard Auto Brake setting accepting that they will to stop further down the runway? The risk here is that although a safe landing should still be achieved, the safety margins are reduced – perhaps just to the point where a slick, wet, rubber coated, portion of the runway is the difference between tarmac and grass. Perhaps a change of brief for the use of brakes or heightened awareness would be valuable.
Thus from a small selective risk based speculation, there could be many avenues of research or opportunities for operators to check their understanding of the issues; providing preventative factors and improving safety – reducing their risk of an overrun.

[Globally]

Alf. Many thanks for the insightful information and questions you pose. From my experience flying B747s around the world for the past 15 years and 22 years in the USAF flying C-141s, I have often seen airports that are very marginally capable of supporting big airplanes. Quito is one of them. The runway should be made longer, the ILS glideslope issue resolved somehow so that crews can stay on a constant glideslope all the way to touchdown in the first 3,000 feet, where the traditional runway markings are indicated. Other airports include Mexico City, where a very tight VOR approach and final turn to the runway 05R is sometimes required - at night during cargo operations. Very little time to get stable on final approach, with ground speeds approaching 200 knots. El Doret, Kenya - unreliable ILS signals, a very small, marginally satisfactory turnaround area at the end of the runway, with a steep dropoff and no margin for error. Norfolk NAS, where I first flew into and out of in 1975 in C-141s, still has a totally unsatisfactorily short runway for big B747 type of airplane operations, some 30 years later. Lagos, Kinshasha, Cairo West, Kathmandu, even JFK in New York on the Canarsie approach. Don't forget Runway 4R at JFK, a Cat 11/III runway only 8400 feet long. How many big airplanes have overrun this runway in the past? Several. Midway is the most recent US example of an airliner overrun. Teterboro comes to mind also. For all of these operations, the crew is "briefed" to be aware and be cautious, etc... But what it all boils down to is the crew is told that the airport is difficult and the burden is on them. There is no room for error. In all of these cases, the airline can point to the fact that the data "shows" that the airplane is capable of performing on these runways, both for takeoff and landing. That is true. All of these operations are capable and legal. However, in my opinion, the question in aviation is not how much runway is necessary to take off and land an airplane on a particular runway . The question is how much runway is necessary to make that operation safe? The data no doubt shows that an Airbus A340-600 is capable of stopping on a wet Rwy 35 at Quito after landing at the ILS intercept point with a given autobrake setting. The margin of safety, however, is probably not that great. Everything had to work almost perfectly, including wheel spinup necessary for thrust reverser activation, etc...