I edited the available footage and created a continuous video that is perfectly synchronized so there is no time gap or overlap. This gives a better idea of how the speed of the aircraft varies throughout the runway. The second half of the video is the same thing however I don't use one of the camera angles as it overlaps another.

http://www.youtube.com/watch?v=oT2RLbHz-rI

After a analyzing the video (using reference points, etc) I found that the aircraft speed remained mostly unchanged at around 60 m/s or 216 km/h.

This was recently confirmed by Infraero who claimed the plane touched down at 110 knots (~ 200 km/h) and left the FOV of the last camera also at 110 knots. (source: Globonews TV)

air france/yyz also took 17 seconds to get into reverse after touchdown...18 seconds for southwest/midway.

ONE question is the thrust reversers status...There is a post indicating that number two was on MEL. certainly post crash analysis will answer thrust reverser use.

Kudos to the gentleman who posted the warning about going around after thrust reversers are deployed...I've not seen good enough imagines to verify if the number one thrust reverser had been deployed, even if the number two was stowed iaw MEL.

rules of thumb about speed...for every one knot extra 2percent more runway

for every 10 feet higher than normal at the threshold, an extra 200 feet of runway needed .


this was a demanding landing...for the pilot's sake, I hope the FDR shows on speed on sink with firm touchdown in the TDZ.

Doors to Automatic,
Let's wait for the FDR....? We just don't KNOW what happened, and what they did.
An EMAS would have made no difference.... they went off the side of the runway, well wide of where an EMAS might have stopped them.

My point is that had there been an EMAS they might have continued with the landing rather than attempt a very late GA. But you are right we should wait for the FDR and the CVR.

christian j

I disagree with you about the emas...certainly if the plane was completely out of control and no attempt at go around was made, emas wouldn't have stopped them...BUT:

if the crew knew that there was emas that would stop them, a desperation play of a go around after thrust reverser deployment might not have been needed...they might have gone straight ahead into the emas.

if there was no attempt at go around and the number one reverser was pulling the nose left, given an emas ahead, cancelling reverse, regaining control INTO the emas would make sense.

it will be awhile before really knowing on this subject...but facing a blast fence at the end, I might have swerved...facing 500-1000feet of emas...I would have gone straight ahead like a prisoner of 30 years heading straight to a date with raquel welch!

Re post #199 “the other flights previous to this one landed safely”.
 

This assumes that all of the conditions in the accident situation are the same or sufficiently similar to the previous landings to produce the same result.
The braking performance on contaminated runways is very variable, just as 2.9mm of water (not contaminated) vs 3mm which is (but only by definition) will not protect you from an excursion, neither will accepting without question what has gone before. Hydroplaning speeds (and characteristics) vary with small and seemingly insignificant changes in conditions. In addition to the often quoted relationship between speed and tyre pressure, and factors involving a firm touchdown or the depth of water at that point, there are also factors of tyre type (material), tread pattern, and tread wear. Then add minor changes in wind direction (which could also pool water in patches on the runway), aircraft systems availability, malfunction, and crew behaviour, then you have a completely different situation.
This is a very good reason to be wary of reported braking performance from preceding aircraft (PIREPs); it only relates to that specific aircraft, that crew, in the conditions at that time.

You are in charge of your landing and only you can make the judgement about the reported conditions. Yet again the question of ‘can the aircraft land here’ must be restated as “should the aircraft be landing here”, and of course asked by a whole range of people, not just the crew who may not have sufficient information to judge – even if they might believe they have because it’s a familiar airport.

Hydroplaning Ref Aircraft Performance on Contaminated Runways. - 12 Mb

non-pilot speaking: If the photo in #195 shows standing water being illuminated by the landing lights, then they would have had little chance.

DtA in #200:Not necessarily. As you will doubtless have read, the runway had just been resurfaced, was in the process of 'curing' and not yet grooved. This was the first sustained rain on it and so pilots could not be expected to know the expected performance.

Politics/spin/today's news
 

Whether the condition of Congonhas’s newly paved runway is eventually shown to have contributed or not to the TAM accident, it is seen by much of the media and the public as yet another example of government bungling, following on the Gol/Legacy collision, ATC black hole, the flip-flopping over ATC privatisation/increased militarisation. Added to which, scandal after scandal involving politicians and including Infraero management.

Responsibility for air transport safety in Brazil is split between so many different government entities now that power struggles are inevitable, as are the attempts to avoid blame when something goes wrong. ANAC, ministry of defense, the airforce, Infraero and a few others.

When something does go wrong, more parties get involved. In the case of the Gol accident it was the Federal Police, the judiciary and Congress. They do not coordinate actions and frequently work at cross purposes. Political parties tug and push; the media does likewise. It’s not all that much different in other countries.

So far, the government’s disaster response has been to disappear from public view, although president Lula, at a ceremony, expressed regret and said he’d ordered the Federal Police (!) to inspect the runway. Some sort of statement is expected tomorrow Friday 20 when “changes” are to be announced – the rumour mill in Brasilia is in top gear. The only representative who’s shown his face is the president of Infraero, to say the runway wasn’t to blame; he’s also pointed out the “smoke” coming from the A320’s port engine, which looks to most other observers more like spray blown forward.

A lot of people were surprised at the alacrity with which Infraero released those clips. It would have been more like Brazil to have hidden them from public view. There’s no suspicion of their having been tampered with, but the speed at which they were wheeled out to compare the two landings seems almost distasteful – even though it’s been tremendously elucidative to observers who would otherwise be in the dark.

Evening news developments:

TAM’s president confirmed to Globo today that the starboard thrust reverser had been inoperative since last Friday 13th and that they had 10 days in which to correct it. Globo say the captain of the same aircraft reported the runway as very slippery on Monday.

Sifting through the media expert interviews, most seem either convinced or accepting that:
a) Touchdown speed was normal and that they did not land long.
b) The port engine was still in reverse thrust when the aircraft passed the cameras and approached the end of the runway.
c) A GA was likely being attempted. Most are very cautious on this, some adamant based on the speed, none denying the possibility.
d) Standing water MAY have been a factor but rainfall at the time would indicate less than 1mm overall was likely.

Do they dispatch with only 1 T/R operative?!? (non-pilot but working for a major manufacturer) I remember when the A310s were having trouble with the T/R locking mech, but BOTH were disabled if 1 was inop. :confused:

anyone care to guess, based on picture posted on previous page, if spoilers were deployed?

I ask the same question bomarc. Difficult to tell, but does seem to put to rest any argument about whether #1 was in reverse or not.

brian

I can't even tell about number 1 TR from the picture I see...is it deployed?

Flash on the Video
 

Has anyone commented on the flash visible from the left side of the aircraft on the video just before it disappears from view?
http://www.cnn.com/video/#/video/wor...nding.televisa
Edited to fix link.

(my similar earlier post somehow was not posted)

One year ago in Irkutsk (Russia) it was somewhat similar
disaster. After landing and deployment of a reverser A-310
suddenly got full forward power and hit concrete structure.
Oficial report blaims crew that (allegedly) unintentionally moved main gear
while disengaging reverser. Second reverser was INOP (MEL)
for several days. Many pilots disputed this alleged strange hand kinetics
and suggest that wrong INOP reverser locking procedure may
cause mulfunction -- unexpected forward power.

Initial guessing were long speedy landing and G/A but non were proven right. Black boxes revealed normal landing and no GA attempt. In contrary,
pedal breaks were applied all the way, but full forward power moved
the plane to concrete structure. Apparently, the crew did not recognized
full power...

RIP.

An observation for what it is worth.
.
I have seen many A320 landings at our airport (similar runway length although grooved) in light wind conditions.
The visual dynamic (as seen) would be similar (from our tower) to that of the camera position in the video i.e. mid field ish’ and about the same distance from the thresholds (given relative aircraft size in the video etc)
.
Assumptions based on nothing:-
.
1. Touchdown at normal position
2. Touchdown speed within normal limits
3. Runway wet not flooded
.
Assumptions based on info here:-
.
1. Runway newly surfaced
2. Runway un-grooved
3. One previous over run/run off on the new surface (on the Monday previous)
4. Other aircraft landed without over run the night of the A320 accident
5. No 2 Rev inop
6. No 1 Rev operating (video)
7. Spoilers deployed (video) although not conclusive from the video quality IMHO
.
Questions arising:-
.
1. Should the aircraft appear slightly nose down (as is clearly visible on brake application during a normal landing of this aircraft type) or minor vertical oscillations (nose up and down a small amount on the nose oleo) if braking was having any retarding effect intermittently (even if aquaplaning)? .. as it does not look compressed to me???
2. Would the Rev thrust be deployed at or before application of brakes?
3. What could a crew do if the Rev are deployed and no brakes/ing available?
.
I know absolutely zip about Airbus systems, I do however remember a thread on here not that long ago about an exciting land and exit (an A321 from memory) where a certain config, or a change of config was required to get wheel braking …. Again, might be irrelevant, however based on what I have observed (generally speaking) even if aquaplaning or speed on touchdown was at play, by the time they reached the position as depicted in the Video i,e the upwind end, they would still have lost much of their speed.
.
It ‘looks’ completely wrong to me!:uhoh:

one reason that the nose might be down is excessive speed associated with "wheelbarrowing" (sp)

proper thrust reverser use would pull the nose down too

the images are not conclusive, but certainly raise rational questions

if plane landed fast, on nosewheel first...yikes

Here some references to Irkutsk disaster:

http://aviation-safety.net/database/...?id=20060709-0
http://en.wikipedia.org/wiki/S7_Airlines_Flight_778
http://www.avianews.com/russia/2006/november/22a.htm (rus)

... I actually think the nose is 'uncompressed' compared to normal i.e. lack of retardation forces :ooh:
.
I have edited the previous to correct the intent :ok:

Whilst I continue to favour the probable causes as (in order) being:

1. runway braking action/hydroplaning
2. deep landing and/or
3. higher than desired speed
4. late reverse selection

there is one other possibility that could contribute that is so far unmentioned.

That is that they were doing a non precision approach as part of training - the wx reported on page 1 would not preclude it. If they then forgot to 'Activate the Approach' [easy to do on the bus on an NPA] and selected 'managed' speed at the OM/4d, the commanded speed would increase to 250kts. This would then be detected, but in the meantime would destabilise the approach, the extent depending on the duration of the speed increase.

Just for the sake of completeness and without knowing what NPAs are available.

Seems like Australia media today are doing their bit to sensationalise the fact that one RT was inop:
While they do attribute it to info from TAM, they seem to be doing their best to make it seem like the fact they took off with it inop was what caused the crash :eek: