Go Back  PPRuNe Forums > Flight Deck Forums > Tech Log
Reload this Page >

AF 447 Search to resume

Tech Log The very best in practical technical discussion on the web

AF 447 Search to resume

Old 20th Nov 2009, 17:24
  #101 (permalink)  
 
Join Date: Mar 2002
Location: Surrey, UK
Posts: 834
Probably the biggest use-case for those ships is as cable ships; there's always a mad dash to charter them when there's a bad cable break. A few years ago, when there was an earthquake at sea in the straits between Taiwan and Okinawa which took out multiple cable systems, there were something like 6 vessels on station at once, and a lot of people hoping nothing else broke for a while.

The two biggest operators are Alcatel and Global Marine Services of London. Which should make the usual suspects wet themselves all over again. didja no it a FRENSH airplane with LIMEY wings?
steamchicken is offline  
Old 23rd Nov 2009, 10:58
  #102 (permalink)  
 
Join Date: Jan 2004
Location: LPPT
Age: 53
Posts: 431
RE: tracer dyes

Simplest ideas are usually the quickest to deploy, and often the most reliable.
Just make the fuel traceable. Wouldn't be too hard/expensive to do it.
Even in the event of an inflight breakup it would narrow down the search area quite considerably.

It's been already done when adding specific smell to gas for safety reasons.
GearDown&Locked is offline  
Old 23rd Nov 2009, 12:35
  #103 (permalink)  
 
Join Date: Feb 2007
Location: Currently within the EU
Posts: 317
NOT a simple idea.

Even in the event of an inflight breakup it would narrow down the search area quite considerably.
Fuel discharged at altitude scatters over a large area and largely evaporates.

Just make the fuel traceable. Wouldn't be too hard/expensive to do it.
In the case of AF447 there was little trace of fuel. How would a marker within it have helped?

What sort of fuel additive could be produced in sufficient quantities to trace all fuel used in all trans-ocean flights, in sufficient concentration to show up immediately in a search, but without acting as a contaminant at any combination of environmental extremes?

No. A marker needs to be non-consumable, and close to the structure that is to be located.
Sallyann1234 is offline  
Old 23rd Nov 2009, 13:09
  #104 (permalink)  
 
Join Date: Jan 2008
Location: above it all
Posts: 365
.. it seems wikipedia already has a list of unrecovered flight recorders, though how complete it is is anybody´s guess:

List of unrecovered flight recorders - Wikipedia, the free encyclopedia

The boxes have been proven crash proof, fire proof and water proof. Making them easier to find in deep waters should be an immediate priority. Of course, retrofitting all airliners with improved pingers, for instance is not an easily accomplished task but what else is there?
Finn47 is offline  
Old 24th Nov 2009, 13:24
  #105 (permalink)  
 
Join Date: Jan 2004
Location: LPPT
Age: 53
Posts: 431
No. A marker needs to be non-consumable, and close to the structure that is to be located.
Point taken.

Some underwater cameras use a calibrated compressible marker in the event of going under the max certified operating depth for warranty reasons. A simple dye marker bottle with a similar device (frangible in this case) on it's cap, attached to the boxes themselves should do the trick.

If we wanted to spend some good money, it could be possible to use some of the old missile technology, and fire/unlatch a very small and conspicuous boey attached to a thin and long wire from a small box on the exterior part of the plane. It could be used as the beacon antenna . Conditions to deploy it: depth and lack of movement.


There is already a similar system used for submarines today. Example here.

Last edited by GearDown&Locked; 24th Nov 2009 at 15:38. Reason: "marker" (not "maker")
GearDown&Locked is offline  
Old 24th Nov 2009, 14:51
  #106 (permalink)  
 
Join Date: Mar 2002
Location: Surrey, UK
Posts: 834
Come to think of it, if you need a marker that's detectable at low concentrations and remotely (for example, from a maritime patrol aircraft), isn't the answer a radioactive substance? It's been done for various purposes.

No point putting it in the fuel for reasons given above. But some kind of structure designed to breach easily could do it. Of course, using teh radiations would run into all kinds of other problems (just think what the chemtrail types would say - or is that a feature, not a bug?)
steamchicken is offline  
Old 26th Nov 2009, 23:43
  #107 (permalink)  
 
Join Date: Aug 2003
Location: Sale, Australia
Age: 75
Posts: 3,829
Posted here as the other threads re 447 seem to be locked. Mods please do as you see fit, just thought it an interesting incident, given possible similarities.

From November issue of Aviation International News.

http://www.ainonline.com/news/single-news-page/article/pilot-suspects-static-electricity-in-citation-x-pitot-failures

Pilot suspects static electricity in Citation X pitot failures

By: Vladimir Karnozov
November 1, 2009

Static electricity may cause pitot static probes to fail, according to a Cessna Citation X owner-pilot who survived a simultaneous failure of all three pitots during a flight earlier this year. Kirill Minovalov, a Russian entrepreneur and private pilot, was flying in stormy weather conditions when the incident happened; he managed to land safely at Moscow’s Domodedovo Airport.

Minovalov, 38, was quick to take advantage of Russia’s economic reforms in the early 1990s. In 1994 he formed Bank Avangard and still serves as its president and CEO. He was urged by the Russian Business Aviation Association to discuss the serious safety incident and spoke exclusively to AIN.

Seven years ago, Minovalov bought his first aircraft, a Dassault Falcon 10, and he has since logged 2,500 hours as a pilot in that airplane and the Citation X. He also owns an AgustaWestland A109 Grand, in which he has 350 hours.

On July 27, Minovalov was at the controls of the German-registered Citation X. Built in 2003, the airframe had logged nearly 2,400 hours and 1,660 landings.

Due to thunderstorms in the Moscow area, air traffic controllers placed the airplane at a rather high altitude, 39,700 feet, over the villages of Sukhotino and Skurygino (22 miles south of central Moscow). At around 1 a.m. the crew was cleared for descent.

The initial descent was rapid, at 5,500 feet per minute, and in between two thundercloud fronts, 25 nm to the right and 40 nm to the left. At around 34,500 feet the Citation X entered heavy turbulence.

A minute later Minovalov and his German copilot saw light shining on the other side of the windshield. “For the first time in my flight experience I saw an electric charge; it was shining brightly like welding [torches]. A golf ball in size, it was sitting on the shroud of the windshield airflow system,” Minovalov recalled. Apparently, a huge amount of static electricity had amassed on the airframe. Its protruding parts, such as the shroud and, quite possibly, pitot probes, were carrying high charges of electrical current, Minovalov surmised.

Thirty seconds later the pitot heater fail left warning light came on. The crew was not too concerned about this since the speed indication remained accurate. But after another 30 seconds the speed-measurement system suffered a complete failure. All three pitot static probes were apparently producing incorrect readings.

The captain’s and copilot’s indicators gave an airspeed reading of some 40 knots, while the standby instrument was on zero. Pitot heater fail right and pitot heater fail sb warning lights came on. The pilots also got an audio low-speed warning at this point.

The incorrect speed reading caused the yaw damper to disengage and issue the warning yd fail–lower. Other aircraft systems responded to the false readings. For example, mechanical limitations for rudder and aileron deflection adjusted to the wrong speed reading.

The Rolls-Royce AE3007C1 engines produced enough thrust, but their full authority digital engine controls (Fadec) reacted to the erroneous speed reading by activating reverse [reversion] mode and generating a fadec rev adc l-r message.

The cabin pressurization system appeared to be fooled by the wrong speed reading. Both pilots sensed bad pressure settings with their ears; it was rather uncomfortable, but bearable. Later Minovalov discovered that control of cabin pressure and pitot heat in the Citation X is linked.

“Having accepted the controls, I felt the yoke and pedals had wrong gearing for the actual speed, requesting very careful handling,” explained Minovalov. A sharp deflection of hydraulically boosted control surfaces might have led to entering dangerous flight regimes or airframe structural damage.

To their credit, the captain and copilot acted in unison, sharing a common view about how to cope with the situation. The crew preferred “vertical speed” mode to “flight level change” in following the flight directors and ATC commands. They focused on keeping airspeed within the safety corridor while descending at some 2,500 feet per minute, once heading, gyroscopic horizon, barometric altitude and descent rate readings seemed correct, and the radio and flight directors remained intact.

“We flew through darkness sparked by lightning flashes all around, no visual reference to the ground,” Minovalov recalled. “There was a strong feeling the airplane had been flying too slowly, and it was tempting to add thrust. But doing so may have resulted in [exceeding] Vne [never exceed speed].”

The crew asked air traffic controllers to keep them informed of their groundspeed. “I did not know what the wind was, but, having information on speed from the ground, I could figure out that, despite the feeling of too low a speed, the airplane in fact flew rather [more] fast than slow.” When the airplane was at 27,900 feet, the air traffic controller reported ground- speed of 397 knots.

The shining ball of light outside remained visible for a minute or two. “I cannot recall exactly when it vanished since I was preoccupied with smooth handling and keeping safe speed, while the siren screamed alarm. But the ball was certainly on for quite a while,” Minovalov said.

The Citation flew in turbulence for some four minutes, getting out of it at about 19,500 feet. Back in stable air, the crew checked the circuit breakers. Then Minovalov tested the system by pressing the yaw damper button. Everything went back to normal and the yd fail-lower light went off. In a split second the system displayed the correct speed reading.

Then Minovalov turned on the autopilot, which also worked. Some warning messages remained on the screens for another couple of minutes and others disappeared one by one. Pitot heater fail lights went off midair, and fadec rev adc l-r at landing. As the airplane taxied to its parking position, no warning lights were illuminated.

The next day essential information about the case–including files from flight recorders–was passed to FlightSafety International and Cessna.

Not an Icing Incident

At the request of the manufacturer, the pilots discussed the incident with Cessna over the phone. It was hard for them to convince Cessna that the incident had not involved icing. “I frequently fly from Moscow, sometimes to Innsbruck [in Austria], and so I know very well what icing is like,” insisted Minovalov.

In his view, the symptoms were different from what would have happened if the pitots had been iced up. The speed readings on all three indicators dropped simultaneously, while icing normally causes smooth changes depending on the altitude. All three pitots failed within a split second and started operating again in tandem. What’s more, there was no rain and the ambient temperature outside the aircraft was -15 degree C.

Minovalov is convinced that static electricity was the root cause of the pitot failure. He believes that a static electricity charge can create a plasma that affects the air flow. Rather than being stuck, the pitot static probes were not getting a rush of air flow, which resulted in all of them having the same incorrect speed reading from the pressure measured on both ends of the tube. Incoming airflow was unable to create a difference in pressure since the plasma prevented it from entering the pitot probe.

Minovalov and his crew were back flying in the Citation X the next day. He said that he had complete faith in the aircraft.

“What happened the previous night was merely a natural phenomenon,” he said. “Static electricity charge and plasma build up in certain weather conditions and naturally disappear when ambient conditions change, leaving aircraft systems intact. In a way, it is like icing: the substance builds up and disappears, and the airplane is fully operable again.”

Soon after the incident the Citation X underwent scheduled maintenance, and all systems were found to be working. Neither the manufacturer nor aviation authorities required any additional work on the airplane.

“After that flight, I began my own research into what happened, this natural phenomenon. I also read much about Air France Flight 447 [the June 1 crash of an A330-200 into the Atlantic Ocean],” he told AIN. “In my view, we experienced the same phenomenon. We both flew in heavy turbulence. The French crew also radioed about static electricity charge. It could be nothing else but them actually seeing a shining ball. There is some evidence that the A330-200’s engines changed mode; in my case the Rolls-Royces went into reversion. Reportedly, the other airplane had also had the yaw damper and autopilot disengaged. It seems to me that the chain of events and the flow of failures were much the same in their case and mine.”

However, there are differences between the two incidents. Unlike the Airbus over the middle of the Atlantic Ocean, the Citation flew over land in the vicinity of airports, with sufficient ATC support. “Seemingly, in my case it was a lot more comfortable, morally and psychologically,” Minovalov admitted. “Besides, it was easier to maintain safe speed on descent than in level flight at high altitude.”

Importantly, the Cessna has a yoke, not a sidestick like the A330. If the speed reading is incorrect, the flight-control system’s gearing in pitch, yaw and bank channels may become inadequate and cause greater difficulties for handling.

It is important to note that speeds, descent rates and altitudes of the Citation X’s troubled flight were typical, much the same in everyday use by many fast jets. This makes Minovalov believe that the same incident could happen again.

The hypothesis that a static electricity charge can create plasma that blocks airflow is something that has previously been considered by pilots, but evidently no one else has yet reported simultaneous failure of all pitots.

Cessna responds:
This appears to be an isolated event. We have had no other reports of this type in any of the 305 Citation Xs, which have accumulated some 1.3 million flight hours to date. Extensive maintenance was done on the airplane in an effort to determine the cause of the incident; however, to date we have been unable to determine the probable cause. We have obtained several system components from the aircraft, have subjected them to extensive testing and have not been able to duplicate the event. We are keeping the FAA fully informed concerning the scope of our investigation and our progress.
Brian Abraham is offline  
Old 27th Nov 2009, 13:06
  #108 (permalink)  
 
Join Date: Dec 2007
Location: france
Age: 71
Posts: 74
AF 447 : significant events

« The crews can inherit latent conditions created by people far removed in time and space from the event. »

Slideshow: http://henrimarnetcornus.20minutes-b...1981295835.pps
SPA83 is offline  
Old 27th Nov 2009, 13:40
  #109 (permalink)  
 
Join Date: May 2002
Location: GC Paradise
Posts: 1,020
...I would strongly suspect icing of the pitot probes that exceeded the heating capacity of the probe heating anti-ice system...

...but then again, what the heck would I know..?
FlexibleResponse is offline  
Old 28th Nov 2009, 20:26
  #110 (permalink)  
 
Join Date: Jun 2009
Location: NNW of Antipodes
Age: 76
Posts: 1,331
"The crews can inherit latent conditions created by people far removed in time and space from the event"

Capt Gérard Arnoux, Capt Henri Marnet-Cornus
As clearly documented in their powerpoint presentation, latent factors were clearly involved in all incidents involving the Thales AA pitot probes. Sadly, the same latent factor in the form of 'latent heat' will ultimately be found responsible for the AF447 upset.

Even though other factors including 'why' the a/c was where it was etc. will be raised, the energy contained within water vapour should never be under estimated, as water in whatever state will always win.

mm43
mm43 is offline  
Old 4th Dec 2009, 13:18
  #111 (permalink)  
 
Join Date: Jun 2009
Location: Newcastle
Age: 49
Posts: 560
Just a quick one.

A "transponder" does not have to be located within the "black boxes". Just located in the same vicinity with the same robustness as them to give any potential searcher an idea where to start looking 4000ft under the ocean.
MATELO is offline  
Old 4th Dec 2009, 17:03
  #112 (permalink)  
 
Join Date: Jul 2009
Location: Surrey, UK
Posts: 130
I was told yesterday by people that support the operation of the Rov Homer that if Airbus/Air France/Whoever really wanted to have found the FDR they would have had ships mobilised and in the search area far quicker, and they would have done a deep (c 2000m subsea) trawl with a listening device as first activity
HamishMcBush is offline  
Old 5th Dec 2009, 08:45
  #113 (permalink)  
 
Join Date: Nov 2000
Location: Melbourne,Vic,Australia
Posts: 390
Come to think of it, if you need a marker that's detectable at low concentrations and remotely (for example, from a maritime patrol aircraft), isn't the answer a radioactive substance? It's been done for various purposes.
Vague memories of my father doing this a few times. IIRC snag is to have something with a unique signature which is both detectable and which can give a concentration (for tracing currents) a fairly short half life is required. The stuff (mostly a gold isotope) was dissolved and in the sea within 24hrs after it came out of the reactor.
Deaf is offline  
Old 6th Dec 2009, 09:18
  #114 (permalink)  
 
Join Date: Feb 2008
Location: Subterranea
Age: 66
Posts: 186
Pilot suspects static electricity in Citation X pitot failures

The French crew also radioed about static electricity charge. It could be nothing else but them actually seeing a shining ball.

Can someone enlighten me where in the official BEA reporting the AF447 crew radioed about this issue of static electricity? The only reference about this issue I could find in the reporting is flight LH507, a Lufthansa B744 preceding AF447 by about 20 minutes at FL 350. This crew reported that `They saw St. Elmo´s fire on the windshield on the left-hand side.´

I have checked Appendix 3 of the BEA Interim report which contains the AF447 radiocommunications transcript but it does not mention anything about static electricity.


Regards,
Green-dot
Green-dot is offline  
Old 6th Dec 2009, 12:30
  #115 (permalink)  
 
Join Date: Nov 2001
Location: UK
Age: 65
Posts: 76
Re: Pilot suspects static electricity in Citation X pitot failures


Interesting. I wonder what paint formulation/type/manufacturer was on that Citation compared with the AF A330.

Also, if the theory is correct, than it wouldn't really matter which make of pitot-tube were fitted.
Backoffice is offline  
Old 7th Dec 2009, 08:53
  #116 (permalink)  
 
Join Date: Oct 2009
Location: Australia
Posts: 34
Guys get it through your heads - They will Never find AF447 A330

Its not in Air France or Airbus "BIG PICTURE" best interests to do this
FlyBoy737800 is offline  
Old 7th Dec 2009, 09:40
  #117 (permalink)  
 
Join Date: Jun 2009
Location: Newcastle
Age: 49
Posts: 560
Quite a sweeping statement to make Flyboy.

I suspect though, it will be in the best interests of all pilots & air passangers world wide to discover what happened to AF447.
MATELO is offline  
Old 7th Dec 2009, 20:51
  #118 (permalink)  
 
Join Date: Aug 2005
Location: Devon, England
Posts: 248
Makes sense MATELO!
manrow is offline  
Old 7th Dec 2009, 22:06
  #119 (permalink)  
 
Join Date: Aug 2009
Location: Germany
Age: 63
Posts: 1,809
BEA communicate

Hi,

Information du 7 décembre 2009 :

Le BEA a ouvert une enquête sur l'événement qui s'est produit au cours du vol de Rio de Janeiro – Paris, AF 445, dans la nuit du 29 novembre 2009, à l'A330-203, exploité par la compagnie aérienne Air France. En effet, l'analyse de cet événement est susceptible d'apporter un éclairage complémentaire sur l'accident survenu le 1er juin 2009 entre Rio de Janeiro et Paris à l'A330-203, vol AF 447
The BEA has launched an investigation into the event that occurred during flight AF 445 from Rio de Janeiro to Paris, during the night of 29 November 2009, to the A330-203 operated by Air France. An analysis of this event is likely to throw some additional light on the accident on 1st June 2009 between Rio de Janeiro and Paris to the A330-203, flight AF 447.
Information, 07/12/2009

PPRuNe ref:
http://www.pprune.org/rumours-news/3...yday-call.html
jcjeant is offline  
Old 8th Dec 2009, 00:14
  #120 (permalink)  
 
Join Date: Jul 2007
Location: Edinburgh, UK
Age: 64
Posts: 39
"Quite a sweeping statement to make Flyboy.

I suspect though, it will be in the best interests of all pilots & air passangers world wide to discover what happened to AF447."


Indeed it is.

Last edited by ILoadMyself; 8th Dec 2009 at 00:17. Reason: No link to original post
ILoadMyself is offline  

Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

Copyright © 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.