Crash Pilatus Porter PC-6 near Namur (Oct 2013)

[airazurxtror]

An aircraft (Pilatus ?) carrying paras, departed from Temploux, has crashed at Marchovelette (or Gelbressée ?), near Namur, at 15h30 : first reports of around ten killed.

http://www.lalibre.be/actu/belgique/un- ... e5f9eedb97

http://www.lavenir.net/article/detail.a ... 9_00377627

[jan_olieslagers]

See also http://www.deredactie.be/cm/vrtnieuws/b ... eergestort

Very sad indeed.

[fretn]

Terrible news, and my sincere condolences to the victim's families. I hope they find out quickly what caused the problem.

[andorra-airport]

1 Person thinks that it is the "OO-NAC" (http://twitpic.com/dhz12t). That airplane was also involved in a crash in 2000. (http://www.airliners.net/photo/0362786/)

[Nevihta]

OO-NAC indeed, looks like the wing "separated" from the plane...

[simulator]

history of this aircraft..

http://www.pc-6.com/history/710.htm

sad news.....

[Bralo20]

There's an active AD on the PC-6 regarding corrosion, wear and cracks on the wing / wing strut fitting

http://ad.easa.europa.eu/blob/easa_ad_2 ... 7-0241R4_1

The plane need to be checked for it every year.

[Passenger]

There's an active AD on the PC-6 regarding corrosion, wear and cracks on the wing / wing strut fitting

http://ad.easa.europa.eu/blob/easa_ad_2 ... 7-0241R4_1

The plane need to be checked for it every year.

And it surely has to be done profoundly for 44-year old aircraft with an accident history.

[jan_olieslagers]

It has to be done profoundly for EVERY plane, of whatever age, and of whatever condition.
Not another round of Antonov/Tupolev bashing, please. Airframe age is a very secondary factor in danger rate.
Or, if you want, tell me the age of the airliner in this animation:
http://lessonslearned.faa.gov/ChinaAirl ... pop_up.htm

[Passenger]

It has to be done profoundly for EVERY plane, of whatever age, and of whatever condition.
Not another round of Antonov/Tupolev bashing, please. Airframe age is a very secondary factor in danger rate.

Nobody here (including me) said something about Antonov or Tupolev. Therefore Jan, your remark "not another round of Antonov/Tupolev bashing please" is not correct. Airframe age is indeed a secondary factor for most of the airliners crashes. But sometimes, it's more then just secondary.

Fact is that the aircraft has lost a wing, causing 11 fatalities.
Fact is that this aircraft had a crashlanding in 2002.
Fact is that age of an airframe IS a relevant factor for metal fatigue.
Fact is that the A.D. clearly mentions corrosion problems with strut fittings. Quote: "...Findings of corrosion, wear and cracks in the upper wing strut fittings on some PC-6 aircraft have been reported in the past. It is possible that the spherical bearing of the wing strut fittings installed in the underwing can be loose in the fitting or cannot rotate because of corrosion. In this condition, the joint cannot function as designed and fatigue cracks may then develop. Undetected cracks, wear and/or corrosion in this area could cause failure of the upper attachment fitting, leading to failure of the wing structure and subsequent loss of control of the aircraft..."

This is a forum and not the official Belgian AAIU. It is my opinion that that the content of the A.D. will lead to the cause of the crash.

[jan_olieslagers]

Even if only out of respect to eleven victims, please do not speculate. There is not the slightest factual indication of the root cause, at the present state.

The EASA recommendation is there for all to see, I am not denying it. But as long as we do not know what actually went wrong, there is not a single reason to refer to it. It is fatally easy to point at this, or at the airframe's age, or at whatever perceived possible cause, without actually knowing anything. That was my reason for the Antonov/Tupolev analogy.

For the sake of this forum's reputation, only serious discussion is wanted. Uninformed speculation is for the tabloids.

[Passenger]

Even if only out of respect to eleven victims, please do not speculate. There is not the slightest factual indication of the root cause, at the present state.

The EASA recommendation is there for all to see, I am not denying it. But as long as we do not know what actually went wrong, there is not a single reason to refer to it. It is fatally easy to point at this, or at the airframe's age, or at whatever perceived possible cause, without actually knowing anything. That was my reason for the Antonov/Tupolev analogy.

For the sake of this forum's reputation, only serious discussion is wanted. Uninformed speculation is for the tabloids.

This is a forum and not the official Belgian AAIU. It is my opinion that that the content of the A.D. will lead to the cause of the crash.

[Didymus]

The pilot's widow is quoted in De Standaard: "If the aircraft gets into a spin it's impossible for the pilot to recover."

I'm just a humble glider pilot-in-training, but this doesn't make much sense unless it's impossible to recover a PC-6. Is this the case?

[Tomskii]

If the aircraft gets into a spin due to a wing that has fallen off it is practically unrecoverable yes.

But you can recover an aircraft out of a regular spin if no other factors arise.

[Didymus]

Well, the loss of a wing isn't mentioned in that article, that's what puzzled me. A layman could conclude from that quote that spins are unrecoverable by definition, which couldn't be further from the truth of course.

I've been told there are airplane types which can't get out of a spin and I'm wondering whether that's the case here.

[teddybAIR]

Spin recovery capability depends on a number of factors and you cannot simply conclude that an aircraft is able to recover from a spin or not. First of all, in the POH you'll find whether a particular aircraft is spin approved or not. Generally, it will not be spin approved if calculations/flight testing has demonstrated that the aircraft structure simply cannot withstand the forces generated in a spin. Personally, I fly the PA28A which is not spin approved as the tail section is expected to separate when trying to recover from a well established spin. A good example is the C150/152 Aerobat, which has a reinforced tail to allow it to handle the forces generated in aerobatic maneuvers.

Next, the ability to recover from a spin will also depend on the weight and ballance. The specific flight envelope of a particular plane can limit the maximum weight and the weight distribution in order to allow certain maneuvers. The primary reason is that the countering moment generated by an aerofoil is function of the force it generates and the moment arm relative to the CG. A long moment arm has a positive effect on the moment generated. Generally, you'll see that the CG is restricted in its AFT movement for maneuvers such as spins to be approved as the rudder and elevator become less effective as the CG moves AFT. Furthermore, a spin is a condition in which both wings are stalled. One of the most effective tactics to counter the stall is to reduce the angle of attack by pitching the nose down, which becomes more difficult with an AFT CG...

So you can see that a spin is a highly complex profile and that the capability to recover from it depends on a large number of parameters. I'm not familiar with the PC-6, so not able to comment on whether it is spin approved/able to recover from a fully developped spin with a full take-off load.

Yet, all the above theory becomes obsolete, the moment you're confronted with a wing separation. In that case you're simply not flying an aircraft anymore. I hope the investigation will learn us how this accident was allowed to develop and that the General Aviation/ Aerial Work communities will draw the correct conclusions to prevent such accidents in the future.

[Passenger]

VTM Telefacts tonight (21h45) is about the crash.

VTM has an interview with a German parajumper who escaped a similar incident (wing from a Pilatus that broke off) five years ago.

[Lenoest]

It looks like the investigation team proceeded with some testing today in LGG. There was a PC6 performing impressive acceletared climbs

[airazurxtror]

The state of the inquiry (in French) :

http://www.lavenir.net/article/detail.a ... 2_00415690

Extract :

«On a pu déterminer que l’appareil était en parfait ordre de vol. Tous les entretiens avaient été effectués en temps et en heure.» Pas de lacune ni de négligence de ce côté.
Comme on le pressentait dès le départ, ce sont les conclusions des experts aéronautiques qui risquent plus que probablement d’être déterminantes.
Et ce sont les conclusions de ces experts que l’on attend désormais. On espère disposer de toutes les informations pour la fin du mois de janvier ou le début février. Mais ce n’est pas un timing précis déjà déterminé.»
«On pourrait ainsi déterminer si la rupture de l’aile est consécutive à un événement ponctuel et brutal ou si elle est la résultante d’une usure plus longue.» L’enquête pourrait ainsi définir si le Pilatus a subi pendant trop longtemps des chocs et des charges trop importants qui ont fini par «fatiguer» et «épuiser» ses composantes.
Une piste évoque ainsi de sérieux problèmes survenus au niveau du moteur juste avant le crash.


We were able to determine that the aircraft was flying in perfect order . All maintenance were conducted in a timely manner . " No gaps or neglect that side.
As we had expected at the outset , the conclusions of aviation experts will more than likely be decisive.
And there are the conclusions of the experts that we now expect . We hope to have all the information by the end of January or early February. "
"We could determine if the rupture of the wing was caused by brutal event or if it is the result of a longer wear. " The investigation could well determine whether the Pilatus has suffered for too long shock and excessive loads that eventually " tired " its components.
Another track evokes serious problems occurred in the engine just before the crash .

[airazurxtror]

The Para Club Namur today has resumed its operations with another Pilatus : G-BYNE.

http://www.pc-6.com/history/631.htm