Emirates emergency landing in JNB

[BigHitDH]

BigHitDH

Did I miss something



quote:
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"Will the fat git in row 44 please make their way forward of the CG please!""
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should that be "Will the fat git in row 44 please make their way to the aft toilets to assist rotation"

Doh!

[Note to self] Drink coffee before posting wise crack [/Note to self]

[BOAC]

Never mind, BigHit - maybe you have solved the Emirates puzzle....

On a more serious note, picking up on 'Who'stheDaddy's' reference to index corrections, it is VITAL that these are only used for small adjustments, as they are normally gross 'rounding-up/downs' for ease of use (otherwise they would be into several places of decimals), and with large weights can give significant trim errors.

[roger99]

As close as it gets, a wake up call??



First of all WELL DONE BY THE CREW TO GET THE A/C SAFELY BACK ON GROUND !!



T/O JNB 21R is most probably 2nd segment obstacle limiting and not RWY limiting. This leads to the conclusion that even with an engine failure at V1 the A/C should have been able to reach well above 35 ft at the RWY end. With all four engines operating, EK 764 probably should have reached + 100 ft at the end. EK 764 used more than 4500 m of RWY before getting airborne, more than 1000 m in excess of what in normally would need. I doubt this was caused by a 3T overload.



One possible contributing factor not mentioned earlier could be MFF (mixed fleet flying). Emirates A340 transition is performed in an A340-300 SIM. Line training and checks are done in the A340-500 A/C. From day one there is a strong focus on rotation techniques and the importance of avoiding tailstrikes. After 50 hrs (4 sectors) on A340-500 the EK pilot is considered MFF qualified. The pilot then flies a mix of A330 and A340-500 flying. All of a sudden a flight on the A340-300 shows up on the roster. (1st a/c entered into service mid March, 2nd on the day of the incident). The EK pilot now goes to work flying an a/c none of the pilots probably ever flew before except in the SIM one to six months ago.



Can you expect a crew to pick up a loading/trim error, slower than normal acceleration, abnormal flex setting or other abnormalities ? I personally believe chances are significantly reduced if none of the pilots ever flew the a/c in real.



Furthermore the differences between the types are not minor ! T/O weights ranging from 233 to 375 Tonnes, packs on T/O on A330, packs off on A 340, A345 has a pitch rotation limiter, the other types don`t, 3 significantly different methods of setting thrust on t/o, significantly less thrust/weight ratio on the A343 than the other types, 2eng performance vs 4 eng performance, totally different methods to adjust speeds below V2 min in the T/O charts only to mention a few. No doubt this is a very demanding task for an aircrew. 3 or 4 type MFF is obviously efficient, but is it safe?



Finally a note on that the A340 crews have received reminders on at least 4 occasions (in every information and instruction regarding A340 entry into service) about “avoiding that tail strike” plus a strong focus on this matter during the transition course. On the day of the incident the following message was sent to the crew:”ROTATION TECHNIQUE AND PERFORMANCE-REMINDER” : “Avoiding tailstrike during the rotation is a critical aspect of A343 operation. Hot, high, optimised performance operations at JNB require particular attention. Use the correct rotation technique, know your pitch target and avoid that tailstrike”. The intentions in the messages are obviously good but maybe the focus on this issue has been to strong. After receiving this message enough times a normal line pilot probably knows about this risk, but how about the opposite, rotating to slowly, very quickly leads to infringements of the 1-eng rwy/obstacle clearance profile. Many operators with heavy a/c experience gives a lot of attention to this. We know that 3 type MFF is demanding and it is efficient, but is it safe??



Last of all: WELL DONE BY THE CREW TO GET THE A/C SAFELY BACK ON GROUND!!

[Arctaurus]

Roger99

A well written and constructive post. You have highlighted the problems in Airbus A330/343/345 MFF perfectly.

[Yo767]

Propellor
Instead of being 'just another number' I could order a Personal Title and help support PPRuNe
posted 14th February 2004 07:33
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Overloaded A-320
Just got to know that a Gulf Air A-320 took off for Mumbai with an error of 11,000 kgs in the load sheet.
The aeroplane was loaded to 11 tonnes over the given weight figure!
Thank goodness there was no engine failure!
Apparently, the crew realized it in flight, and then held over Mumbai for over an hour, to bring the weight below the maximum landing weight.
Details?
Comments?

You can read the rest at: http://www.pprune.org/forums/showthr...light=A320+BOM

So please would you stop talking about that 3T load not accounted for? It makes me freaking scared to see that actual pilots thinks that 3T can make a difference on a A340!!!

I use to sleep peacefully while deadheading untill recently...

Yo le pogo

[Propellor]

I agree with Yo767 that an overload of 3 tonnes on an A-340 should not make a world of a difference. 3000 kgs may sound a lot to some, but is not even a couple of percent of the take off weight of the 340, in my estimation.

All aeroplanes are designed to withstand a certain amount of abuse in line operations and that abuse is commonly a misrepresentation of the actual weight of the plane. Some other examples of abuse are a mis-trimmed take off, rotation at less than V-R, and fast or slow rotation.

The ‘Safety Speed’ for take off, the V-2, and its corresponding V-1 and V-R speeds have some safeties built into them. I do not know the exact amounts but they will be with the manufacturer or the certification authority, for sure.

With all engines operating, the surplus climb performance available on a twin engined airplane far exceeds the surplus climb performance available on the 3 and, especially 4 engined ones. That is why, with all engines operating, an overloaded A-320 managed to fly with about 10 tonnes error in the weight and correspondingly lesser speeds.

Now, I am not assuming or making presumptions that there was a gross miscalculation in the weight ex-JNB on this flight, but if the error is rumoured to be 3000 kgs, then IMHO it is not a significant amount to warrant such an incident.

As far as the ethics of dissecting the incident, well, this remains a column for ‘Rumours and News’, and under the guise of anonymity, one does rake issues that may not surface, especially in some parts of the world. The Middle East is certainly one of them. Most incidents and corrective actions are never publicized and forums like the PRUNE remain the best source of information. (Thanks, Danny.)

In the present case also, no one mentioned an incident, also in Emirates, when the crews miscalculated their take off speeds, not too long back.

[NigelOnDraft]

Propellor / Yo767

I do not know if you have bothered to read this thread. Maybe start at the beginning?

At "Rotate" the PF pulled the stick fully back. Nothing happended... for some time, when eventually the nose rose and they got airborne.

We are not talking an aircraft at the correct attitude and failing to fly - we are talking an aircraft failing, for some time, to even start moving to the correct attitude.

Do you stand by your assertion, that 3T misloaded in anyway on an A343 will not be noticed? As I say, from my A343 days, a ~2T fuel error in the tail (trim) tank caused a similar incident (late slow rotation with full back s'stick)... Maybe I am just a liar?

NoD

[BOAC]

Never mind, NOD - I understand what you are saying

[maybee]

a340 incident

Sorry but I find this post a bit disturbing - first, there are a lot of assumptions. We all should know that there is probably more to this incident than we currently know, however I will make a comment..

A 3000 kg error would probably not cause this incident but what would cause this problem would be incorrect rotation technique OR Technical - see below

Multi fleet flying flying is and continues to be my concern.

If the A340 is rotated as per FCOM you would not have a problem ie rotate at approx 3 deg per sec to 12.5 deg and the aircraft will fly away without any tailstrike - don't stop at 10 deg and wait, particularly if using 1+f for take off config. That will cause a problem - any heavy jet operator knows this. Rotation technique is normally a continues RATE of rotation.

What would be a factor, which would obviously have to be investigated, is if the oleo's were under inflated. This has the potential of this kind of accident.

Please don't blame the crew until the full enquiry has been completed. It could happen to any of us - does not matter what aircraft we fly - could be speed calculation - poor technique - etc

Trying to be fair,

happy Landings

[Plastique]

Airbus issued an FOT last night suggesting that the rotation was consistent with the pitch command - i.e. that the pitch commanded by the PF was not sufficient to generate the required rotation.

[CDRW]

So it looks like first stone is being thrown by the good old manufacturer - pilot error!!!

This does beg a question tho - unfortunately I have not had the pleasure of flying a Airbus only Boeing so apologies on the technical side - just looking at it from an airline ops side - the PF used "incorrect rotation technique" and this caused the aircraft to remain on the ground until 150m AFTER the runway!!! Really?? Was the take off that marginal??

If at Vr the stick is moved back a little bit- lets say a 1/4 of the normal required input - will the nose pitch up "a little bit" or does the stick have to go back to a certain point before the nose will even start to rise??

The PNF - does he/she have any indication of how much movement the PF has put into the stick??

[NigelOnDraft]

If at Vr the stick is moved back a little bit- lets say a 1/4 of the normal required input - will the nose pitch up "a little bit" or does the stick have to go back to a certain point before the nose will even start to rise??

No difference to your Boeing / Cessna or whatever. Elevator deflection purely proportional to stick deflection at this stage. What actually happens depends on how the trim was set (loadsheet etc.). Each takeoff is as per my Boeing days - sometimes it leaps off, sometimes needs a bigger than normal tug etc. - each followed by some sarcy comment about the loadsheet / dispatcher etc. !

The PNF - does he/she have any indication of how much movement the PF has put into the stick??

Not once the TO roll starts - except from looking across!

NoD

[Pontius' Pilot]

PLASTIQUE

I haven't been at the office in the last few days and therefore have not read the FOT you refer to.

Did they mention or refer to the FOT issued on 23 Sept 2003 titled ELEVATOR IN DAMPING POSITION. The reason for issuing the FOT was:

"Two cases of an elevator dropped in full-down position, without ECAM warning, after hydraulic power up, and subsequent to the engine start sequence, have been reported".

It goes on to state that both these cases were identified during the normal flight control checks. The FOT changed the flight control checks as to who responds during the normal flight control check after start, and also added an additional one by the PNF " at a convenient stage, and as close as practicable before takeoff...." to check for the presence of this condition.

The FOT was applicable to all A330-200/300 and all A340 200/300 aircraft.

At the Annual Airbus Safety Conference Oct 2003 held in Barcelona, I recall one of the Airbus test pilots mentioning that this condition would lead to rotation problems if normal elevator control wass not recovered.

[Felix Lighter]

I think youre talking about a different FOT......there is a new one, although I too havent read it yet.

I wonder how may here have actually flown an A343 out of JNB.

In fact 3T can make a huge difference to the take-off performance. Please remember that JNB is often ISA+25 and is 5000ft AMSL. The poor old CFMs are really hurting. Last minute payload adjustments for 1-2deg temp changes are very common.

I wonder if anyone has the METAR or ATIS info from JNB on the day of this incident? What time of day do EK depart JNB?

The 3T being loaded aft is a red herring as when the A340 is perf limited then the CofG is moved beyond 26%. In this case a whole new set of RTOW charts needs to be used....... or if the crew are using ACARS RTOW then they need to be very careful with the numbers they put in the box. It is possible to get large errors in V speeds.

What ever the causal factors....and they will all come out in the wash...... well done to the crew for recovering a very very nasty situation.

[CDRW]

Felix - If a 3T error in the TOW (about 1% or 2%) can make such a difference as you say, I would hate to see what sort of performance you would get if a donkey died a few knots after V1!!!

[Budgie69]

CDRW

Try this simple experiment.

Place 10kg of groceries in a shopping bag. Stand up, place the shopping bag on your shoulder steadying it with your left hand. Fully extend your right arm in front of you and raise it to fascist salute level. Easy wasn't it?
Now move the shopping bag to the fingers of your right hand and repeat the excercise. It is more difficult and more strength is required.

Your legs can easily cope with the weight, but you are struggling to rotate your arm about your shoulder.

If you imagine that your shoulder muscles are the elevator and that your right hand is the nose of the aircraft and you will see the problem.

A 3 tonne error in TOW is minor, but 3 tonnes assumed to be in tail, then placed in the nose is major. It is not about weight, it is about trim. On some a/c trim limits become very restrictive at high weights.

[Angel`s Playmate]

The good thing on the Wonderbus is, that you really can feel it ,
if you are nose or tail heavy on rotation !

....mmmmh, or did I miss something in the course!?


Happy ldgs to all

[wagtail23]

There are a few things which need to be pointed out on this forum which have either been ignored, or incorrectly posted.

CDRW - yes there is an indication on the PFD as to how much input the PF has used. This disappears shortly after take off.

Felix wrote about the altitude and temperature at JNB. Anyone remember the WAT limit, or Weight Altitude Temperature limit for maximum weight at take off? You can bet that the weight will probably been performance limited, so any overload, even 3 tonnes will make a serious dent in your performance, and would have been a contributory factor if true.

Most of us are awaiting the outcome of any enquiry but there will of course be supposition and conjecture at the moment.

[Dagger Dirk]

Under False Arrest

Seen a few pages back (pg4 in post by BigHitDH)

On another note, just how effective are the arrestor beds seen at some thresholds at stopping a several hundred tonne airliner going 160kts plus?

That question itself brings up the contrary aspect:

<<arrestor beds>>
If there had been an arrestor bed in situ on the 21R overrun at JNB, would the extra drag on the aircraft (albeit fairly light on its wheels but still with some degree of oleo compression) have altogether precluded the aircraft getting airborne at all?

I think that the answer might be YES (so maybe gravel arrester beds should be overlaid by a shallow supportive surface - in order that such an outcome might be avoided.

Otherwise I could see a nice overrun equipped with a gravel arrester bed someday leading to a "sticky" end for someone....not just a noteworthy audible "rumble"

[NigelOnDraft]

CDRW - yes there is an indication on the PFD as to how much input the PF has used. This disappears shortly after take off.

Thanks for that - my error. Of course you're right - it's there to judge a small amount of aileron for a x-wind on the TO roll, and presumably disappears as you leave the "take-off" phase? That said, even as PNF, I am never watching it at rotate, but judging the rotate rate, and guarding the sidestick should the rate be alarmingly too little or much...

NoD