Flaperon washes up on Reunion Island
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A question for the engineers. Would the flaperon be drooping down like shown in this photo if all power was lost inflight?
Or is this flaperon droop due to the lack of hydraulics due to the aircarft being stored?
Source: Photos: Boeing 777-2H6/ER Aircraft Pictures | Airliners.net
Or is this flaperon droop due to the lack of hydraulics due to the aircarft being stored?
Source: Photos: Boeing 777-2H6/ER Aircraft Pictures | Airliners.net
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Inflight the airflow will NEVER let the flaperon droop like that by itself. Only at slow speeds can the hydraulics fight the airflow and droop the flaperon. With hydraulics INOP the wing surfaces will be pushed flush.
Last edited by A320FOX; 16th Aug 2015 at 02:35.
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would the flaperon be drooping down like shown in this photo if all power was lost inflight?
see section 11.5.1 here,
http://www.davi.ws/avionics/TheAvion...ook_Cap_11.pdf
"Flaperons droop when initially commanded due to their weight, and then will float until airspeed reaches about 100 kts with at least one engine running. At that time, the ACEs will put the flaperon PCUs into normal mode, and they return to the droop position for takeoff"
777 Flaperons - PMDG 777 - The AVSIM Community
I suggest a bitten trailing edge due drooped water impact with at least one engine running or a ripped engine smashed into flaperon.
EDIT:
RAT deploys if both engines are failed and center system pressure is low. RAT hydraulically powers primary flight controls, including flaperons. So yes, if flaps setting was accordingly.
Last edited by _Phoenix; 16th Aug 2015 at 05:47. Reason: added text
If the RAT deployed, it only powers the centre hydraulics. This only powers the right flaperon. Therefore I think the left flaperon would float up under aerodynamic load and the right neutral.
But it does look like it was ripped off due to flutter before the a/c crashed.
Edited to correct
But it does look like it was ripped off due to flutter before the a/c crashed.
Edited to correct
Last edited by birdspeed; 18th Aug 2015 at 23:21.
Water tight composite components stop ingress of moisture and hence damage due to freezing in flight.
It all seems to have gone very quiet from the officials in France who are examining the flaperon. Or have I missed something?
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I think that what " MTOW" is getting at is why is it taking so long for any confirmation, or otherwise, to come from the experts in Toulouse who initially would only say that "it was likely that the flaperon came from the Malaysian 777".
The quiet is deafening!
The quiet is deafening!
Not sure what you're driving at guys (well actually I suspect I do), or what your rush or need is?
Amongst other things there's a legal process involved, so I'll credit the French authorities for going as far as saying the part was probably/likely from MH. Other than that the enquiry is ongoing, and I rather suspect those that need to know the day to day findings coming out of the lab at Balma are well and truly in the loop.
Amongst other things there's a legal process involved, so I'll credit the French authorities for going as far as saying the part was probably/likely from MH. Other than that the enquiry is ongoing, and I rather suspect those that need to know the day to day findings coming out of the lab at Balma are well and truly in the loop.
I think that what " MTOW" is getting at is why is it taking so long for any confirmation, or otherwise, to come from the experts in Toulouse who initially would only say that "it was likely that the flaperon came from the Malaysian 777".
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Other than that the enquiry is ongoing, and I rather suspect those that need to know the day to day findings coming out of the lab at Balma are well and truly in the loop.
In part we are again seeing the difference between an air crash investigation and a judicial investigation. In an air crash investigation, expected outcome is a "probable cause" as described in an Accident Report. However in a judicial investigation the expected outcome is to prove facts "beyond a reasonable doubt" in a Court of Law, a much higher legal standard.
Presumably various streams are continuing in parallel, jointly by the various teams:
- Work to positively identify the flaperon continues, mainly chasing, verifying and cross-validating all the paper trails in MAS and Boeing's manufacturing & maintenance supply chains. I doubt the French prosecutor will announce anything until they "dot every i and cross every t".
- In parallel, a huge amount of work is required to test / document / characterize the flaperon. This involves a ton of non-destructive x-rays, CT scanning, electron microscopy, ultrasonic inspection, swabbing for chemical residues, detailed observations and photography of any features, tap testing, etc. This alone may take weeks.
- That's before any real analysis can take place, which may involve further testing. Again, possibly weeks.
- At some point they may want to do some destructive investigation, e.g., cutting up parts of the flaperon to better understand the impact mode, etc. This may conflict with the legal evidentiary rules so again it will take time to sort out.
In short I don't think the flaperon will be going back to Malaysia anytime soon but I hope the identification work can be completed sooner rather than later.
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Turin --
That requires the compartment to be completely airtight over the whole altitude range. Otherwise humid air enters the compartment, condenses and the condensate can't escape.
Water tight composite components stop ingress of moisture and hence damage due to freezing in flight.
Yes. Which is why they have drain holes in the assemblies. The individual honeycomb componants will I assume, be watertight.
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Yes, exactly, and such drain holes have to be cleared regularly. I have no idea about sealing of the honeycomb; I suppose it could be designed to be airtight or open but not left to chance. The key thing about this debris is the depth to which it spent its time which depends on water density vs depth and ocean currents, and wind if near the surface. It could have gone up and down many times in all this time.
peekay4
Well said. I doubt few on Pprune actually really need to be in the daily loop on this.
This isn't CSI and I suspect the rest of your post accurately describes the reality of the ongoing process and possible resultant time scale.
Unfortunately the people who really want to be in the loop are the victims' families, and the continued uncertainty from the French side (regardless of the reason) is very tough on the family members.
This isn't CSI and I suspect the rest of your post accurately describes the reality of the ongoing process and possible resultant time scale.
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If the object is a B777 Flaperon then it must have come from MH370.
Or do Flaperons occasionally fall off 777s ?
Never knowingly had one fall off of one of mine, but then I did the outside check preflight not post flight.
Or do Flaperons occasionally fall off 777s ?
Never knowingly had one fall off of one of mine, but then I did the outside check preflight not post flight.
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Presumably over the years a number of such flaperons have been damaged and removed as unserviceable, and scrapped - and are then handled as general industrial waste. So you cannot quite rule out scrap junk getting washed into the sea somehow somewhere in the world! Statistically MH370 has got to be a thousand times more probable as a source! Nevertheless, the origin has to be proved, it cannot be assumed.
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They would have pulled it apart by now and confirmed the printed part numbers etc on the internal parts. Something very suss is going on here. Not to mention that it was found back in May.
you cannot quite rule out scrap junk getting washed into the sea
confirmed the printed part numbers etc on the internal parts
Not necessarily. For one getting at the internal parts is a destructive process, I'm sure there is a lot of evidence that may be gathered from the surface of the component, investigators will want to make sure they have done all they can before taking it apart. Also as someone already said, given the ongoing criminal probe, there is a restriction on what and what not may be done (and by whom). Even if it was disassembled, I'm not sure there would be any unique identifier numbers within the structure. Non-life limited parts such as a flaperon need not be traced during their lifetime, internal components would only have part numbers. Only the completed assembly would have its unique S/N but that placard is as we know missing.
Last edited by andrasz; 18th Aug 2015 at 04:30.