Airplane Crash over Tripoli

[Evan]

G'day Evan,

Are the 330's equipped for a 2 NDB approach? Depends on what the company concerned ordered. Some are, and some aren't. I would personally guess that an African airline would order them with, as many of their airports would have them... but that is just guessing.

While NDB and VOR approaches are not ideal, they are a part of world aviation that we have to deal with. However, the pilots would have had the assistance of the IRS system (specifically when updated by GPS) to fly the approach, using the "raw data" off the NDB or VOR to verify the integrity of the navigation display. The A330 will usually fly a VOR approach in exactly the same manner as an RNAV approach.

You say it is a sorry excuse for ground based guidance, however you need to remember that the minima and procedures are completely cognisant of that fact. It is KNOWN that NDB approaches are not particularly accurate, which is why the terrain splays and minimum altitudes are so large/high. If you can't see the required amount at the minima, you go around. Simple.

With mist, sunrise etc, that all adds to the possibility of missed approaches - it shouldn't increase the chances of crashing.

The site certainly looks nothing like a stall - it looks very much like a high-energy impact like Evan has said.

This is from an updated (2009) plate showing the added VOR+2Lctr approach:

[Highkeas]

..........There are other reasons why it's generally more dangerous for aircraft near departure or rival. .................

Weather is another reason - microbursts, icing of airfoils, wet runways, and fog. Accidents have also occurred due to impact with local structures. And of course pilot error such as taking off or landing on the wriong runway (or the wrong airport - I know of two close calls).

[Gabriel]

Having looked at the pictures, here's my reaction. Maybe the vertical stabilizer had such strains put on it it tore off.

Except it didn't.

[mawheatley]

Could this be significant? Quote from AP hosted here: http://www.google.com/hostednews/ap/...2uZgQD9FM3PU00

"The main runway is positioned in an east-west direction, with most arriving aircraft flying in from the east because navigational aides are at that end of the runway and the prevailing wind is from the west. Airliners normally land and take off against the wind because it makes the process easier."


"Still, the Afriqiyah Airbus approached the runway from the west, although the airport weather report showed the wind was blowing in the same direction. The pilots were thus looking directly into the sunrise while searching for the runway and also had to contend with an early morning layer of haze that reduced visibility at lower altitude."


"A European pilot who has flown to Tripoli numerous times said the standard approach was from the east. He described as "strange" the decision to come in from the opposite direction, particularly in light of the wind direction."

Why would they be landing WITH the wind, and from the direction where there are less navigational aids? Plus the lack of fire pointing towards fuel starvation? Do we know if an emergency was declared?

[Gabriel]

I've read that the ATC radar confirmed that they were not busting the MDA prior to the crash.

What does that mean? I can conform with 100% certainty that they were below the MDA just prior to the crash.

Evan, I'm not trying to say that the NDB approach is as good as an ILS, or that it's Ok that the main airport in a country lacks an ILS approach, or that the pilots intentionally busted minimums, or anything. All I'm trying to show in an attitude described by some as "troll" is that so little is known by now that there is no hint for any of the speculations that have been proposed, and that whatever little evidence is there is even contradictory to some of the speculations.

What we know is:
- A-330 in final approach.
- Crashed.
- And disintegrated on impact.
- Killing all but one.
- In weather conditions that were not ideal but not that bad either.
- Oh, and the composite fin didn't fail because it's still attached to the metallic fuselage.

What we don't know is:
- If there was a fire or explosion before or after the impact.
- If there was any fuel remaining on board.
- If the pilots intentionally busted minimums.
- If it crashed under control and then cartwheeled.
- If crashed at an odd attitude (bank, pitch)
- If the pilot were drunk, fatigued, you name it.
- If there was some sort of structural failure before the impact.
- If there was en engine failure.
- If any computer had any glitches.
- If it crashed almost 1 ft before touchdown or fell from 500ft.
- If it crashed near the runway or far away.
- If the pilot was following any instruments approach.
- etc, etc, etc...

For what I know so far, ignoring the historical frequency of the causes and judging only for the known results, it could have been with about equal probability an meteorite, a pilot's suicide, a structural failure, several computers gone crazy, a loss of situational awareness, you name it...

[xspeedy]

I don't remember the exact figures but something like 95% of automobile accidents occur within 5 miles of work or home or some other frequent familiar destination.

This is a bit of a flawed stat, as to drive farther than five miles from home requires first driving that five miles twice (to and from destination). Not to mention that a disproportionate amount of trips will be within five miles of home - dropping kids off at school, going to the grocery store...

[Evan]

What does that mean? I can conform with 100% certainty that they were below the MDA just prior to the crash.

Evan, I'm not trying to say that the NDB approach is as good as an ILS, or that it's Ok that the main airport in a country lacks an ILS approach, or that the pilots intentionally busted minimums, or anything. All I'm trying to show in an attitude described by some as "troll" is that so little is known by now that there is no hint for any of the speculations that have been proposed, and that whatever little evidence is there is even contradictory to some of the speculations.

What we know is:
- A-330 in final approach.
- Crashed.
- And disintegrated on impact.
- Killing all but one.
- In weather conditions that were not ideal but not that bad either.
- Oh, and the composite fin didn't fail because it's still attached to the metallic fuselage.

What we don't know is:
- If there was a fire or explosion before or after the impact.
- If there was any fuel remaining on board.
- If the pilots intentionally busted minimums.
- If it crashed under control and then cartwheeled.
- If crashed at an odd attitude (bank, pitch)
- If the pilot were drunk, fatigued, you name it.
- If there was some sort of structural failure before the impact.
- If there was en engine failure.
- If any computer had any glitches.
- If it crashed almost 1 ft before touchdown or fell from 500ft.
- If it crashed near the runway or far away.
- If the pilot was following any instruments approach.
- etc, etc, etc...

For what I know so far, ignoring the historical frequency of the causes and judging only for the known results, it could have been with about equal probability an meteorite, a pilot's suicide, a structural failure, several computers gone crazy, a loss of situational awareness, you name it...

I believe that means that it has been reported (unofficially of course), that they were not holding below their minimum decision altitude on purpose, for the purpose of sighting the runway early in conditions that had sent a previous flight off the approach. I believe that is what I meant, and not that the wreckage is still hovering somewhere above MDA. But feel free to speculate on what I meant there, or anything else for that matter. This is a speculative forum by Jove. I will continue to speculate based on what little is known, and ask questions and hopefully get valuable responses from thoughtful people.

But you are right, we know very little right now, so see ya when the report comes out. Of Libya. In about ten years.

[SYDCBRWOD]

Except it didn't.

It's EC's next hobby horse - he's heard the tail is composit, and because it is separated from the rest of the fuselage in one of the pictures, he figures it has fallen off, thus causing the crash. Ergo, all composits are evil.

Of course he conveniently seems to have ignored the large amount of aluminium that the tail is attached to that has clearly failed in the crash. Point being it appears the conventional aluminium structure has failed, not the composits.

[TUNISAIR745]

"A European pilot who has flown to Tripoli numerous times said the standard approach was from the east. He described as "strange" the decision to come in from the opposite direction, particularly in light of the wind direction."

Why would they be landing WITH the wind, and from the direction where there are less navigational aids? Plus the lack of fire pointing towards fuel starvation? Do we know if an emergency was declared?

The reason why they flew an NDB approach can be for training purposes...

Many African airlines, or in general, airlines around the world practice NDB approaches, ILS and sometimes VOR are not always available, and i think it's pretty embarassing for an airline to divert because their pilots weren't skilled enough to land with minimum aids!

My point is that afriqyah lands in many african airports, which unlike european ones, having an ILS installed is nearly a luxury, so we can't blame the pilots for their choice to fly an NDB approach

[ZK-OKH]

Any further news about the Alitalia pilots that witnessed the crash while waiting for take-off? I would not underestimate the assessment of two professionals.

There are rumours about the version of the two AZ pilots have given: they reported that the plane put the nose down toward the ground and roll over. This can be the reason of the almost total disintegration of the plane. Thinking about it this accident is very different from the Turkish 1951 that crashed on its belly when it was at low altitude reducing, as a consequence, the force it crashed in the ground.

[SYDCBRWOD]

I heard once that current aircraft are not overbuilt like some older aircraft such as a 727, DC10 etc. Maybe that's the reason for so much pulveration.

Pulveration? What the? Do you enjoy making up words? There are a plethora of existing english words you could try using rather than making up new ones. How about puverisation (not that it describes particularly well what we can see in the pictures, as the definition of pulverisation is the act of grinding into a powder or dust), how about disintegration which would probably be a better fit.

Your argument about modern aircraft not being overbuilt smacks of the hoary old stories that older cars were built stronger too. Of course the mere fact that the people travelling inside the car were stuffed seems to be ignored, but the important thing was the car didn't even bend... Using finite element design, every component has been designed to be strong enough to do its job at whatever overload condition that may be. There is no point in designing something 'stronger' as it will add weight, which impacts everything downstream of that component. More weight requires the structures around it to be stronger and heavier, which requires larger brakes, larger engines etc, it's a vicious circle. I'd rather be in something modern which is arguably less likely to drop out of the sky in the first place, is more likely to feature for example interior fabrics that won't off gas toxic fumes in case of a fire etc.

[ZK-OKH]

Fire signs?

Are these fire signs? Is possibile in your opinion that a fire that occured in the wreckage has been extinguished and nor witnesses nor media has told anything about? Or these are signs of an internal fire? or they are just black material? What do you think? This shot is taken from pprune.org

http://i337.photobucket.com/albums/n385/motidog/TIP-002.jpg

[Gabriel]

I believe that means that it has been reported (unofficially of course), that they were not holding below their minimum decision altitude on purpose, for the purpose of sighting the runway early in conditions that had sent a previous flight off the approach. I believe that is what I meant, and not that the wreckage is still hovering somewhere above MDA. But feel free to speculate on what I meant there, or anything else for that matter. This is a speculative forum by Jove. I will continue to speculate based on what little is known, and ask questions and hopefully get valuable responses from thoughtful people.

But you are right, we know very little right now, so see ya when the report comes out. Of Libya. In about ten years.

Ok, now I understand what you meant about the MDA.

As for the rest, I support and practice the sport of speculating. I also practice the sport of signaling lack of (or contradictory) evidence in others speculation.

Because I try to support both my speculations and comments about others speculations with data, and explain the reasons why I say what I say, and I try to be respectful, I consider my practice constructive.

[mawheatley]

The reason why they flew an NDB approach can be for training purposes...

Many African airlines, or in general, airlines around the world practice NDB approaches, ILS and sometimes VOR are not always available, and i think it's pretty embarassing for an airline to divert because their pilots weren't skilled enough to land with minimum aids!

My point is that afriqyah lands in many african airports, which unlike european ones, having an ILS installed is nearly a luxury, so we can't blame the pilots for their choice to fly an NDB approach

Yeah, OK. But WITH the wind? And INTO the sun?

[Gabriel]

There are rumours about the version of the two AZ pilots have given: they reported that the plane put the nose down toward the ground and roll over. This can be the reason of the almost total disintegration of the plane. Thinking about it this accident is very different from the Turkish 1951 that crashed on its belly when it was at low altitude reducing, as a consequence, the force it crashed in the ground.

Well, a landing accident a la FedEx's DC-10/MD-11 is the first thing that crossed my mind when I heard the rumor that the plane was still Ok as close as 1m above the runway.

While in those cases the airplane rolled inverted and remained almost intact (expet with one wing less), a too hard landing can very well end with the airplane disintegrated, as seen in Sioux City.