Afriqiyah Airbus 330 Crash

[apdak]

I crashed an Airbus once.
Here's my account on how i bought the farm.

The first time I did a go-around in an Airbus with the autopilot disengaged, I expected that natural tendancy for the nose to lift up on giving power as it had with every other aeroplane that i had flown before that.

Because the airbus fly-by-wire system demands a 1G loading with the autopilot out, the nose did not lift an inch. Now with very little back stick input from my side, it went hurtling with almost full power atraight ahead into the ground infront of me.

Luckily this was in a simulator.
I have no doubt though, that had this not been so dramatically demonstrated to me that day in the sim, I would never have been so aware of the danger that this particular trap represents. It takes a monumental pull on the stick (almost full tilt) to get the desired amount of rotation...

A go around, at, (or even below minima) especially having lost visibility, doing manual flying, in a high powered twin at low weight, has DISASTER written all over it, in an Airbus if you are not accutely aware of the trap.
Maybe this is what happened?

[bia botal]

Thanks to C-SAR for his great work, I wonder can someone please answer a boeing man some airbus questions.
With ref to the tail most likely striking the ground first,what is the AoA for a tail strike, versus the pitch attitude the FD would command in a go-around.
After watching the videos of the Habsheim accident is it possible that the crew just got it so low that it tried to land.
And a observation, with reference the photos on post 611, in particular the shot of the tire, score marks can be seen on opposing sides indicating that the wheel at the time was not rotating, surely this could indicate that the undercarriage was in a less than vertical position or indeed fully retracted.

[C-SAR]

PapaThreeCee said #599

There were reports in earlier threads about the aircraft hitting the roof of a house. Does that house appear to the far right in the third page of your overlay (titled "Impact") ?? If so, would that be the actual point of initial impact, even before the aircraft struck the utility poles / wires?

Few pages back I answered a similar question: in my opinion, the house being mentioned is the little shack next to the mosque, to the west of it along the east-west road. This house is already after the impact point, so no surprise that it was showered by debris, but it is not in the line of travel (it is to the right of the path) and as I said, AFTER the first impact point. The power line was hit before the impact point.

[Sir Richard]

JetThePilot

Initiating the go-around at minimums (about 250ft aal) still gives you 15 seconds before ground contact at 1000 fpm rate of descent....plenty of time for the engines to reach full power !

[Nickdj]

TK1951 flight impacted hard with substantial hull rotation at impact, but the fuselage stayed relatively intact.

TK1951 came down with a speed of approx 100kts in a moist dirt field. Seen by the length of the debris trail of this crash, you can easily make out that the velocity of the aircraft was a lot greater. What i also noted was the fact that the engine found had no engines blades left what so ever. I would presume this to be because the engine was giving a high amount of thrust (i.e. TO/GA).

C-SAR, thanks for the great time you have taken with the images!!!

[C-SAR]

mike-wsm said in #620

Have you looked at the area before impact, and is there any evidence of engine thrust? Blown sand, blown-over trees or whatever?

I did and I didn't see anything that looked like relevant (but it does not mean that they are not there..). The tracks visible from the overflight video before the impact point are of a makeshift road. A car is also visible and the white marks further on are just left overs from previous buildings. The google map being old(er) shows buildings that are not there.

To All:
Thanks for your thanks but please stop doing it... no mention no attention...

On a more general point, all of you familiar with accident investigations will agree with me that I was lucky to have a peek at the site. In the large scheme of things, mine was just a blink of an eye. I know that I have missed 80% or more of the clues and information that is there. Of course a peek is better than nothing, but please do not loose the perspective that I could (and probably am) wrong in some of my assumpitons due to the limited time to properly analyze the information.

Thanks. C-SAR

[valvanuz]

Soooo:
1. Full power was added below minimums
2. At minimums, GA was not (properly) applied
3. ...

[JetThePilot]

Sir Richard

Initiating the go-around at minimums (about 250ft aal) still gives you 15 seconds before ground contact at 1000 fpm rate of descent....plenty of time for the engines to reach full power !

Agree under normal conditions with no buildings, tall trees, power pylons, etc., that may be under the flight path on approach. But by the time full power is on, you are well below 250ft, right? Factor in reaction time and I am sure we can agree on the rest.

The point I was trying to make is that in cases of loss of power the approx. 5 seconds AirBus manual at minimums may not be enough, more slack needs to be allowed to avoid breaching minimums.

[andrasz]

Having been away a few days, I cannot see much new aside [edited out, thanks anyway ], most of what I summarised in #40 still seems to stand, with the exception of the final moments that are not supported by the contact marks.

I still maintain however that the aircraft must have struck at a highly unusual attitude. It does appear that the complete disintegration was the result of a rapid pitch-down following tail separation (with a possible tumbling around the axis of the wing box, shredding the fuselage but keeping the wing structure relatively intact at the farthest point of the wreckage field). However for the tail to have completely separated, the aircraft must have been either in a very sharp nose up attitude, or the vertical speed must have been very high. With the latter being improbable even in a blotched approach/go around scenario, the first is the more likely.

There have been a number of speculations about the hardness of the ground. I am very familiar with desert surfaces (including Libya), from what I can see on the photos of the impact site the subsoil is a mix of gravel and clay covered by a thin layer of sand. Such surfaces are very firm, will easily support a car without any meaningful sinking of the wheels, and may be strong enough to actually support an aircraft on wheels. This layer of gravel and clay will extend to a depth of several metres before bedrock is reached. The firmness is indicated by the fact that the tail only dug a trench of less than half metres, in soft ground that rut would have been much deeper. Had the plane made a gentler contact with this type of terrain, it would have just slid along, probably the only major damage being the shearing-off of the undercarriage (more due to unevenness of terrain rather than the wheels sinking in)

[RadAlt2010]

Flying Bagel and 411A (how does this guy find the time to fly when he made 7000 posts I'll never know):
Both of you are the type of crop duster pilots that we are all glad to see the back of. I hate to break this to you, but aviation has changes since the 1950's Dakotas and Constellations. Accent is now on safety, regulation, CRM. Its not just about you and your airplane, its about the safety of your passengers foremost.

"From what I gather, TIP is not half as bad as some places I fly into. Third world countries are just that, third world."

If you have been reading my posts you’d know that I wasn’t referring to TIP singularly. I am saying ALL major international airports of the world have to be audited,rated, monitored. If you want to fly into some death trap do it on your own, don’t take passengers with you.

[silverstrata]

Andraz:
Had the plane made a softer contact with this type of terrain, it would have just slid along, probably the only major damage being the breaking-off of the undercarriage.

Indeed, rather like the Heathrow 777. Wet London clay is such a flattering surface to inadvertently land upon. (Note the 777 hit wheels first, not tail first. Tail first is a possible indicator of a failed go-around for the A330).

But the other factor is the energy involved, be that in airspeed or thrust. One would have thought that the speed would be low, and the extra energy was provided by thrust - but in this instance, anything could have happened.

[Right Way Up]

JetThePilot,

The minima will take into account obstacles in the approach zone and also of the height loss after go-around.

A possible scenario that I alluded to earlier in the thread that I have heard no evidence to disprove, is the scenario that occurred in Melbourne. On an approach a decision to go around is hampered by not selecting the TOGA detent, the aircraft will continue descending at the same rate possibly with MCT power & the gear retracting. The acceleration would be significant.

[JetThePilot]

Right Way Up

What you say makes sense. Minima is not to be breached - initiating GA or recovering speed need to be initiated above minima in descent at or above minima. That is the point I am trying to make. You cannot give yourself 5 seconds to do that, few more seconds are needed.

From what C-SAR posted it seems that 8U771 did not have landing gear deployed at point of impact. This supports what you said about the Australia incident. However, with regard to disintegration, I agree with what has already been posted. Surface should have slowed the plane considerably if there was alot of drag, but it appears to have hit several tress and pylons and that would have resulted in loss of structure integrity. Hitting the RAISED road after that at high velocity (just see how far the wings are and you will realise massive thrust was applied to them) meant a weakened structure is totally destroyed.

[andrasz]

Originally Posted by silverstrata

One would have thought that the speed would be low, and the extra energy was provided by thrust...

Concur, thrust by itself can wreak havoc - just think of the Etihad 346 in Toulouse. They had no more than 20-30m of roll at takeoff thrust (and even that not free, but slipping brakes), and the front of the aircraft was basically shredded. Fuselage is built for torsional strength, but has very little resistance to longitudinal compression. If the tail broke off as it appears, the engines running at full power would have driven the nose into the ground, disintegrating the front fuselage to the degree we see.

[Right Way Up]

JetThePilot,

If you go-around at minima, you pitch at a normal rate towards approx 15 degrees which will take roughly 4-5 secs. At the same time the engines will be spooling up towards TOGA and again that will take roughly 5 seconds. The engine thrust increase should be quick enough to maintain speed whilst carrying out the pitch manoeuvre. The altitude loss if the manoeuvre is carried out correctly will be roughly 20-30 feet. Even allowing for 3 secs pilot delay the total loss will only be 50-60 feet which is still safe if not advisable. If a pilot delays more than that then you cannot account for that behaviour or lack of ability. It is quite safe and proper to go-around at minima.

[Boeingrestricted]

removed my prev.

800-1000m from treshold = 200 feet in alt. speed given the pax numbers will be around 135kt........ See the pics no skidding marks what so ever results in 1 conclusion a big bang. I would say a crusader attack from the western intelligence services..Or maybe from christianist extremists

[wilyflier]

rapid pitch down

Having hit , then lost its tail, we had the equivalent of a tailless aircraft not designed with sufficient pitch stability. I have seen this happen with hang gliders , at even at slow airspeed the change of attitude in a "tuck"is so sudden , 12 degrees nose up to 90 degrees nose down in a flash, that the pilot can continue forward to instantaneous bone breaking injury on the airframe. The negative angle of attack accelerates the rate of descent to a high figure at once.Im not surprised the A330 was so completely shattered.Not a cartwheel., maybe the pieces tumbled .
Wilyflier

[ivarpenris]

I'm a reporter of a big Dutch newspaper and had brief contact through email with the pilot of AlItalia who was an eyewitness of the crash in Tripoli. He posted a message on what he saw on the forum of anpac.it. The press-officer of ANPAC told me one brief passage of his post: the plain had far too much speed and was touching the ground with a backangle of more than 20 degrees. A Dutch flight-expert told me that this indicates that the pilot must have been disorientated and that he tried to pull up the plane in the last seconds.
My question: are there any Italian pilots here who can login to the (closed) forum on the website anpac.it? If so, can anyone send me the passage this Italian pilot wrote? As you might know the majority of the victims is Dutch and relatives of them are very interested in everey detail there is to tell. Please leave your message here or send it to: ivar.penris at ad.nl.

[one post only!]

Not sure if its already been discussed (probably) but what about the scenario that because they were flying a NPA, if they were flying it in approach mode and then performed the GA at just below minima (or the very unfortunate millisecond time window after minima) that the engines go to full power but you don't go into GA mode. The thing just spears on towards the ground until you take over. One of the holes lining up?

Someone mentioned a while back that this airline wasn't cleared to fly managed approaches though so I imagine they would have been in raw data so should not have had this problem?!?

[Interflug]

Where is the cockpit located in the picture sequence? Where did the (remains of) the cockpit end up, I have not read any information in that regard? Probably not in front of the wings, so the wings must have overtaken the cockpit in the breakup sequence...