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Couple the low airspeed with yaw to the right induced by full forward thrust on the port engine, full reverse thrust on the starboard engine, and insufficient control authority coupled with decreasing airspeed and subsequent stall, and it's not looking good at all. http://static.pprune.org/images/smilies/sowee.gif

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Could the ground maintainance engineers have touched a wire (by accident) that connects to the Reversers when 'Quickly' cutting off the fault??

Sounds odd that the Reverser was open on the Starboard Engine.

Just a 'Theory' that's all.

No Beef.

BYALPHAINDIA;

The complexities of discerning organizational influences, especially in terms of examining the traces back to original causes, is difficult, requiring special training, experience and support for the "broader" view. This isn't to say they're not there or to say that by their obscurity they are merely distant antecedents with less validity. Cultural aspects play huge roles within organizations but that role is invisible to all because it is "the way" things are done -the underlying assumptions are similarly invisible. We don't see "normal" - we only see "difference" when it emerges. It's akin to hindsight in terms of understanding what happened.

Most directly involved want "the" cause and are impatient if not in disagreement with complexity because they want some one or some thing to blame, typically not themselves.

Whether what you say is relevant or not depends first on those involved having the sense of such factors so they may see them for what they are and how they influence "normal" decision-making and how abberant decisions are "made normal", (as did Diane Vaughan in her book, "The Challenger Launch Decision" well worth purchasing/reading as is, "Organization at the Limit" about Columbia).

In other words, if one is examining a decision-making process (returning to gates, continuing with MEL items etc etc etc etc...), one must also remain cognizant of the organizational environment in which such decision-making takes place.

Pilots especially, are keenly aware of "the unwritten" and "the unsaid" in corporate cultures and may either be encouraged to exchange information with the organization's leadership or, as is almost universally the case, the leadership of the organization can dismiss them as "expensive resources" in hopes that they continue to fly the company's airplanes on schedule with minimal fuss and disruption.

I believe this touches on some of the matters you raise in your post.

Almost certainly not. That's not the way airplanes or mechanics work.

We know absolutely nothing that is meaningful or important about the reversers, the engines, the takeoff, the flight path, the crew's demeanour etc etc. Even videos are not "knowledge".

Knowledge of the fleet type is part of a good discussion as is discussions about SOPs and what is actually known about the flight.

But it's a free discussion. (Steve, don't waste your breath and blood pressure on trolls...).

PJ2

I believe two survivors described being bounced side to side, I was wondering if this could be a response to a "rudder dance" (from the perspective of rows 14-19), as described earlier in this thread?


EDIT: It seems a little soon to speculate on the TR(s) being open contributing to this accident. They could have been purposefully opened after touchdown.

Speaking as an electronics bod, I couldn't agree more. These are simple, inexpensive, reliable and effective. Heck, even my local pub has 8 cameras continually recording video to hard disk for security reasons. The visual (and possibly aural too) evidence such a system could provide would be invaluable. And no reason any longer to rely on questionable eye witness reports.

Ditto for landings too btw.

The Pilots' union letter to Spanair stating their concerns was basically your usual generic mostly-political-agenda in faith of a pending 1,100 jobs cut and pay reduction for another 700 employees plan propossed by the company recently. The pilots complained that "bad management" and bad "ground operation caos" was starting to affect fly security by means of "more stressed enviroments" among "delays, cancelled flights, insufficient man power".

I think it's fair to assume it's not "directly" related to the unfortunate accident. I have taken 6 Spanair flights between the Canary Islands and Madrid in the past two weeks prior to this accident and indeed one was cancelled and several delayed.

Spanair has promised more technical information about the accident to the families Saturday at 6pm.

Nothing else I have seen reported on the press except that whatever little wind there was (raging between about 7 and 9 knots) was actually tail-wind. Spanair approves of MD-82 fit to take off at up to 10kt of tail wind.

The flight had been overbooked. An additional couple of passengers was holding a ticket and reportedly checked-in luggage, but reached the gate 3 minutes late and were denied boarding. The flight operated at full PAX, so I don't know where they were planning on sitting them even if they had reached the door on time, not to mention that the airplane returned to gate after the "overheat warning red light" (likely a warning for a outside-air-temperature probe system malfunction) came on and finally took off over 1h late.

Again in low-ish air density, high-ish temperature conditions, presumably max. weight with good visibility on a "brand-new" long-ish airstrip where they reached V1 (perhaps a bit later than "normal"), VR, nose up, front gear left the ground, likely the back gears too w/o visual or reported anomalities other than perhaps a "bit weird nose angle" (no info on flaps/slats) and then perhaps moved erratically while airbone (survivors not clearly stating if felt "side-to-side" movement ocurred airbone or on the ground) to then for unknown reasons "attempted to land" (or falling down) again, bouncing-around, reportedly hitting briefly the ground with a wing (which doesn't seem to have left any large debri on the strip or produce extensive visual damage to the airplane structure at that point, but was reported by source cited as viewing the security footage), presumably sustaining some damage due to somewhat violent touch-down over max. landing weight (witneses saying things like "started to break in pieces", but no pieces seem to have been reported that close to the strip) and lost direction veiring off the runaway and later crashing against obstacles at presumably high speed a few hundred meters later with perhaps at least one thrust reverser properly deployed, leaving a river of fire along its path.

Skid marks were left on the landing strip that seem to show all three wheels were touching ground "properly" and braking on a "normal looking" straight line for a short while and then turning somewhat steeply to the side (significant strip length was still available in the front), exiting the runaway to the terrain in-between strips where it crashed very violently (hardly any pieces larger than a car where left at all of the whole plane and debri and victims expanded a significantly large area, thus the high victims count).

There is no clear account reported exactly like that, but it's what can be infered by the vague comments reported by press from witnesses or "oficials".

All that has been said repetidly and clearly is that "no fire was visible until it had 'hit the ground' 'several times' (bouncing around).

Some survivors seem to have been "ejected" from the plane landing in a small creek. One of them approached the wreckage and helped rescue two children. Most survivors seem to have suffered at least one (usually more) fractures (mostly limbs, limbs+ribs or limbs+skull). Many were "low mass" people (3 CHD, several women). There were possibly a few more inmediate survivors, but the fire spread quickly (vegetation didn't help, one survivor with internal burns from inhalation, one survivor helping rescue a woman's child at her petition only to return and find her and her other child 'unrescuable', one survivor and one of the first ground rescue personnel accounting for some people shouting "I'm soffocating" or "help"). Rescue efforts were very prompt and effective, but very challenged by the fire, very large spread-out scenario and not so easy terrain access.

One initial survivor died soon after in the hospital, leaving the total count to 19 current survivors. Only 4 of those remain in severe condition. Doctors are hopefull for all, but one passenger remains critical. Several are basically fully recovered (except for the fractures, which obviously take weeks/months to properly heal). About 50 of the victims have been identified, with the remaining aprox. 100 still in need for DNA identification, as physical matching was not possible. All victims accounted for, although it took an extra day to find the remains of the two initially unaccounted victims, a baby and another small children, at the devastation scene.

So sorry for all the victims and their families :'-(

Like it's normal in us imperfect creatures, we all would like to know what happened and how to try to avoid it and find some strange confort in trying to figure out the truth. I guess it's our way of dealing with the pain and frustration, specially knowing that with a damaged flight recorder the (hopefully) definitive answer on the cause may be many months, if not years, away. At this point, this accident doesn't seem to have a clear-cut probable cause and it seems further speculation on the many possible scenarios could be pointless without more information, so I guess we'll have to sit and wait.

Descriptions like this could help understand the damage that can results of high speed impact, aborted take-offs, unnecessary uneven terrain/vegetation around landing strips, fires, etc, and perhaps will help to avoid it happening again.

You bet your @rse it makes a difference if the plae is overloaded. Although, in all seriousness we all kow that the meager standard weights used these days I personally think that any flight which is at MTOW on paper is a few hundred k's over. That's my opinion based on what I see entering the cabin sometimes, and the exceptional ability (especially the caribbean region) of passengers to have a 20 inch tall handbag weigh close to 30 pounds. The poor carriage wheels got stuck under the weight loooong ago to the point that they are half circle shaped as they've been scraped down to axle :}

But those extra kilo's are mostly carried over in the margin of error calculations, but to add 2000 Kilo's of known overweight into the plane will most definitely affect single engine performance.

I wanted to elaborate on the MD-80 thrust settings, but I see that it appears clear to most.

How much margin is there?
 

xkoote: in your opinion, assuming the MD-82 briefly was successfully airborne for a few seconds and lets assume the worst possible scenario of a bit of overweight, 10kt of tail wind and slightly low air density, a bit understimated V2, a bit oversteep take-off angle and a bit reduced thrust (i.e. slightly bad quality fuel).

How unlikely is that the plane could have stalled even with nothing else "wrong" (i.e. no major loss of engine power)? Does major engine malfunction is basically a necessity for take-off failure or the above conditions coupled with say a 2º error on Flaps deploiment be enough to potentially stall the plane?

If the anwer is what I think, then too many highly speculative scenarios open up on why the pilot could have decided to try to land rather than continue to fly.

Also, goverment officials said they saw the airport security tape and the accident was recorded but that they couldn't see anything significant (for them, speaking as politicians and not aviation experts) on the causes of the accident. In other words, they implied they couldn't see any obvious physical reason for the accident (no major explosions or large fires or obvious engine malfunctions or large errors on operation prior to the abrupt landing, of course, from whatever small image could be seen from the potentially far away camera). They didn't mention the reported wing touchng the floor when it "abruptly landed". They even said something to the bold extend of: "The accident was recorded but there is nothing on the tape as to why the accident happened"

Whch Engine
 

Incidentally, I have read the complete thread and amny reports but cannot find a reference as to which engine was reponsible for the earlier return to gate? I have a feeling this about to become a more important issue. Can anyone confirm based on reliable sources?

What is known about the first return to gate was that a failure indicator lighted on the cabin. The captain informed the PAX that he wasn't sure what it was and was returning to gate to have it checked. He later said (and Spanair and technician in charge of the repairs, through the spokeperson for the airplane repair technicians' union confirms) that the indicator was for overheating of the device that warms the air intake tube orifice (that leads to the outside air temperature probe) to avoid the formation of ice on cold weather. Since the flight from MAD to LPA was not thought to be in any danger of bad weather or ice formation, it was turned off by taking the fuse out, in accordance to approved operations giving a 10 days margin for finding the fault and repair it properly.

The captain reportedly informed the PAX, which remained on board during the aprox. 1h delay, that it was a "broken heat sensor that was repaired" and were now ready to take off (late).

Captain and technician signed the flight fit-to-fly. The technician was totally confident his action couldn't be in any way part of the cause of the accident and expressed his sadness for the loss of the crew which he knew well personally and spent the last minutes of their lives with.

Most sources close to the investigation seriously doubt it was related to the accident, but of course it's being investigated. Worst case scenario would perhaps imply that outside air temperature automatic measurement could be off or not working properly, but even that is unlikely.

With due respect, it is relevant. I've heard some horror stories that are very much based in fact. There are certain events I will not repeat here.

Overweight = BAD in the event of engine out, particularly.

It certainly wouldn't help. Being overweight doesn't automatically mean it'll stop flying, but it means the margins that the pilots are working to could be sufficiently out to put them on the wrong side of the performance. That's where it gets to be a problem.

2,000 kg over when you're looking at 67,954 kgs MTOW = 2.9% overweight.

A valid point is raised regarding standard weights and certain pax, and indeed luggage etc.. At least the luggage is weighed at check-in.

A "standard" male is now considered to weigh 80 kgs. I personally weigh 89 kgs. That's an 11% increase right there.

ECAM Actions.

Luggage may be weighed at check in, but only for the purpose of detecting and hence charging for, overweight bags.
The accumulated weight of the bags at check in is not the figure used for weight and balance.
A standard figure per bag (25lbs under FAA regs) is what is used. On the not unreasonable understanding that some will be under and some over the set weight.
Pax are averaged at 180lbs in summer and five more in winter, once again under FAA regs. Which to be honest seems pretty low given some of the people one sees on the street.
Now add the hand luggage and bear in mind that at least one airline has no limit to weight as long as you can lift it, and it doesn't appear dangerous.
The above figures are as stood the last time I had to know, they may have changed.

"Luggage may be weighed at check in, but only for the purpose of detecting and hence charging for, overweight bags.
The accumulated weight of the bags at check in is not the figure used for weight and balance."

The relevance to this accident notwithstanding, why not? The data's available.

With the reasonably large number of children on the flight, does this alter appreciably this hypothetical overweight scenario, or is it more on the baggage side of things?

According to MD80 stall charts, stall speed will increase about;

1 kt/tonn slats extended
1,25 kt/tonn slats retracted

XPM

There appear to be mixed messages coming from Spanair and the head of civil aviation in Spain regarding the air temperature gauge.

This is from Associated Press and appears in several newspapers.

Police and investigators probing the deadly plane crash in Madrid have questioned the mechanic who cleared the plane for takeoff after tending to a minor mechanical problem, the airline said Saturday. Spanair said the mechanic dealt with a problem in an air temperature gauge that forced the pilot to abandon a first attempt to take off. About an hour later, when the MD-82 finally did take off, it crashed near the end of the runway, burning and largely disintegrating. A total of 153 of the 172 people aboard were killed.
The newspaper El Pais quoted unnamed sources close to the investigation as saying that during two sessions of testimony Friday - first with police and then with crash investigators - the mechanic insisted that the gauge malfunction was a minor glitch which had nothing to do with Wednesday's crash.
A Spanair official told The Associated Press on Saturday it had no details of the man's testimony, but reiterated that the mechanical problem did not cause the crash. The official spoke on condition of anonymity, citing company rules.
Aviation experts have told The AP this problem probably did not cause the crash.
All 19 survivors of the crash remained hospitalized Saturday, two of them in critical condition. The worst off was a 31-year-old woman with burns to 72 percent of her body. Her husband died in the crash but her six-year-old son survived.
Only 50 bodies have been identified so far. Many were burned beyond recognition and forensic teams have been using DNA techniques for identification.

Spanair said the mechanic dealt with the gauge problem by essentially turning the device off, and said this was an accepted procedure because the gauge was not an absolutely essential piece of equipment.
But the head of Spanish civil aviation, Manuel Bautista, told the AP in an interview Friday that the gauge should be closely examined to see if it did contribute to the accident.
Bautista said a combination of failures likely caused the disaster.
''A problem with a temperature sensor may not matter at all, or it can be very important, depending on what other circumstances accompany it,'' Bautista said. ''We will have to see what other issues were present.''
This can be no comfort to the greiving relatives who are seeking early answers.

To SKRIDLOV
Yes the data is available but its' accuracy will depend on lots of factors. The accuracy of these scales can vary by terrific margins (handy hint if they try to charge you excess-use other scales). They may sometimes be calibrated but I have no personal knowledge of this being done.
These scales are subject to enormous wear and tear, dust, being moved about etc. all those fairy light staff jumping on them to see how much weight they have lost.
In other words they are not particularly accurate, and I for one would not like to see them used in a final weight and balance sheet.
The cost of what would have to be done to ensure their accuracy would not be welcome in a business cutting unecessary costs to the bone.
It is mooted that for smaller aircraft, less than 20 pax, the weighing of both the pax and the bags may be useful.
Then of course we get into discrimination etc..and lawyers involved.
As usual things ain't never as easy as they seem to be.

Indeed. I hope that the Spanish authorities can publish an early initial report into the cause of the disaster, before the grieving turns to anger and bitterness.

Could somebody please clear up this business about the OAT probe once and for all?

What I have gathered from reading the posts regarding this probe here is:

1. There is OAT probe located at or inside the air intake of the engine which measures the temperature of the air "ingested" by the engine, right?

2. Then there's some heating device which is turned on to heat the OAT probe if the airplane enters icing or low temp conditions to protect the OAT probe from getting clogged by ice and snow and thus producing false readings, right?

So what the mechanic deenergized was the heater, not the OAT probe itself, right?
The OAT was still operational except that if the airplane had entered icing conditions it would have got clogged because it had no heating, right?

Standard weights
 

I have (probably) survived numerous incidents (accidents) using this simple figure...
100 kg per passenger.
That includes the passenger (his/her fat belly if any), his/her checked baggage, carry-on, and duty free.
xxx
If given "347 pax" from the agent, on MY paper, I write 34,700 kg total payload.
If I am given 330 adults, 15 children, 2 infants, it becomes -
Adults 33,000 kg, children 750 kg, infants "0"... = 33,750 kg total.
I do not care what the official standard weights are. This is what I use for my takeoff computations and speeds.
So far, no chief pilots have fired me because I disregarded standard figures.
xxx
I am still alive after many years of flying - Retiring in 3 months (and happy)...
And in my 747, in does not matter where they sit. The CG is always OK.
No need to say, I have a B.Sc in Math/Physics... and I use that "superior" knowledge.
Takes me 1 minute to get my payload. F/Os or F/Es take 5 minutes, and arrive to... 33,336 kg.
And a lot of wear with their erasers ("rubbers" in UK, and territories).
xxx
:ok:
Happy contrails

P.S. For Scanair departure from LEMD - I would assume their actual payload was 16,500 kg (165 adults?) -

<quote>
"Luggage may be weighed at check in, but only for the purpose of detecting and hence charging for, overweight bags.
The accumulated weight of the bags at check in is not the figure used for weight and balance."

The relevance to this accident notwithstanding, why not? The data's available.
</quote>

Not necessarily; not every DCS has integral W&B functionality, or is able to export the data to an external tool.