Jet we don't know that. Both transponder antennas are close together. It the section of skin they are both mounted on departed the aircraft.....
Just as likely a major loss of electrics....or for some reason multiple databuses went down at once. IMHO: until we recover her, were gonna drive ourselves crazy guessing. Asking again any 777 or 767 drivers remember what the load shedding scheme is? |
Just to point our on some of the information provided by the Malaysian military last night around its last know position, more so around the fact the the aircraft descended to around 3000ft would this simply be to maintain VFR , cloud base in kl usually sits between 3000ft and 10,000ft
this would indicate the the PIC certainly had control of the Aircraft |
The stream of news and rumors is ridiculous
Malaysia's air force chief denied a media report that the military last tracked a missing Malaysia Airlines jetliner over the Strait of Malacca, far from where it last made contact with civilian air traffic control when it disappeared four days ago. "I wish to state that I did not make any such statements," air force chief Rodzali Daud said in a statement on Wednesday. Malaysia air force denies tracking missing jet to Strait of Malacca |
Reagarding the transponder and why it was not returning a secondary paint on radar could be as mentioned above. If a decompressurization did occur, and in the process of changing the code from assigned code to 7700, the PNF left it in Standby mode and not return it to TA/RA mode due to increase in workload or partial or deteriorating awareness due to hypoxia, it may explain why the transponder was 'off'. Quite plausable and we all know how overloaded we can become during simulator proficiency checks for similar scenarios.
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It's the only scenario which I can piece together which fits the evidence. The aircraft could be anywhere from the last primary radar return to 3000nm west of there. - and may not be found for a very long time. |
I have never switched the transponder to standby before changing code.
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ACARS via SATCOM
On the B777, if the SATCOM antenna is damage as a result of fuselage mount cracking could this disable ACARS transmission as well!??
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I have never switched the transponder to standby before changing code. |
Ok, let me ask you this...Any of you had ever turned off the transponder on the flight for any reason? If so why?
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Latest:
@STForeignDesk: #Malaysia official replies "it's not the right time yet" to question from #MH370 families if govt is hiding military data #MalaysiaAirlines |
Compromised cockpit remains an open possibility. :mad:
So do a few other not so happy scenarios. :uhoh: The transponder thing was true in my fledgling days, but I doubt that 777 has such archaic avionics. It is amazing how quickly the mods are ditching posts. Wow. jet noseover: Yes. Was trouble shooting mine. Turned it off, recycled the CB, turned it back on to stby to warm it up. A few minutes later, with the code assigned, it seemed to work based on ATC getting a good squawk out of me. This was over 20 years ago. |
Ditto re stndby on ATC TX. When I learned to fly that was the accepted procedure. Forty-three years ago. Time has marched on since then.
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No never.
Only xpdr change I can think of is a checklist action to go from TA/RA to TA Only following ENG failure/shutdown. |
Jet, I did work on a KA200 that had a duel transponder failure coming into KLAS.
The seal on the R/H cheek panel was no good and they flew through rain. Both TDR-90s had water pour out of them when I pulled them. Unless they have added some wiz-bang feature, it is also possible that A transponder failed. And if they were busy, or ATC didn't call them to point it out, I doubt they would know. No reply does not mean they were turned off... |
The common element for the transponders, VHR COMM #1, the GPS recvrs and the Satcoms is the antenna locations on the fwd fuselage.
That said, and with the understanding that there is a lap joint AD in effect, and with the alleged transmission of cabin disintegration received in Utapao yet one more theory emerges. The Aloha 737-200 was very much shorter and only just held together apparently, so the scenario of a fuselage failure on a 777 being possible, and then allowing for another hour of flight would be astonishing. Although it would explain many data points. |
If the transponder is turned off/on standby, do ATC (civil or military) still get a contact with no associated information? A primary return?
I'm a little confused by the impression I am getting from various posts that a large jet can go "invisible" by switching squawk to standby. Can SSR work where PSR cannot? |
Ok, let me ask you this...Any of you had ever turned off the transponder on the flight for any reason? If so why? To add (not relevant for this case), when we operate in such locations, it's known as 'flight monitoring'. I.e. the control agency will not be able to see us but know that we are somewhere in that area. We will call in every half hour to report. If we fail to do so, they will call to check. SAR will be dispatched only when we are way over due. I think this is very common for GA as well. |
B777FD If you go to standby, the transponder will still hear the interrogations, but not send out any replies. So no, it would not show up on SSR.
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This is starting to sound like a variation of Helios Flight 522:
Helios Airways Flight 522 - Wikipedia, the free encyclopedia The left turn may have been an attempt by one of the remaining crew-members to return to land. Some news reports claim it was a low as 3'000 after turning west - other reports say is was sill up near 30k. If it did drop from the cruse this is further evidence that possibly one remaining member of the crew was making a valiant attempt to save the lives of aboard. |
I'm a little confused by the impression I am getting from various posts that a large jet can go "invisible" by switching squawk to standby. Can SSR work where PSR cannot? |
Thailand will not be wasting their tax payers money over Malaysia authority blame game, sending them to search South China Sea, Gulf of Thailand, Andaman sea, and probably Indian Ocean next.
Missing MH370: Thai Navy may cease hunt for plane |
All this transponder talk is silly. Why would anyone try to select 7700 and not tell ATC anything?
We won't know what happened until they find the black box…if ever. this may go down in history as just one of those accidents where you never find the wreckage. Its a huge ocean…..won't be the first or last time a plane disappears. |
Why would anyone select 7700 and not tell ATC anything? 1) Unable to transmit voice (headsets failure, radio failure) 2) Unable to speak - loud cockpit noise such as canopy failure, partial pilot incapacitation, cannot speak audibly due to 3rd party (terrorist situation) we even have codes following 77xx, to mean other failures, Hydraulics, Electrical, oxy, etc... |
Jet, it is possible a transponder failed (it happens) Unless ATC yelled at them or the failure caused a TCAS error message they may not have noticed.
The point is, no reply from the transponder does not mean someone switch it off on purpose. |
@Weary
In a part of the world historically known for the cultural practice of face saving, who would confess to pulling the trigger? |
I've seen little information about the pilots, other than that the copilot was transitioning. Does anyone know if the pilot regularly flew this route? Seems like someone who "knew" the area well might react differently than someone who didn't in the event of a com and nav failure. He would, perhaps, be more able to determine his position visually based on ground lights, and would be more apt to know of other (even disused) airports. Also, did he usually fly at night? He had a high number of hours and presumably seniority?
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Continuing Transponder Saga
On the 777, if a transponder fails, will it auto transfer to another transponder, or is there a message of failure and a manual transfer to an operating transponder?
The last airplane I flew auto transfered, and gave an advisory message and chime. |
Checking the back weather data, both KL and Penang were essentially calm and partly cloudy all night during the hours when this flight could possibly have been returning in that direction. Broken cloud layers were reported at or near 3000 ft. From what I recall of the satellite imagery (but I was then concentrating on areas further north) there were tropical thunderstorms quite a bit further south (probably south of Singapore) but as usual in this part of the world, dissipating and remnants drifting west. I think we could rule out weather as any kind of a factor in this event, even some theoretical last stage return to base.
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Old Boeing Driver. I have never seen a setup on an American built plane that auto switches. Doesn't mean there isn't one....
Most failures will trip a fault that will show up but some faults in the receive path won't trigger an error, the transponder just won't know it is being interrogated, and won't reply. Jet I agree it stinks to high heaven, but that doesn't mean it was a willful act by someone on the flight deck... |
At the rate this SAR is going, I doubt the debris field, if any, would remain clustered together. I fear that we'll just have to wait patiently for the debris to wash up on some coast, hopefully populated, and then back track the currents and find the crash site.
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The denial by the RMAF chief that he ever stated the aircraft was picked up on radar near Palau Perak is Malaysian face-saving - in case their conclusion was wrong. Radar picks up all kinds of things, not necessarily related to aircraft. The radar results have to be analysed and a conclusion drawn. That conclusion may be right or wrong, when the radar return is from an object that shouldn't be there.
Let's say MH370 definitely was the unknown item picked up by military radar crossing the Malaysian peninsula and tracked to near Palau Perak. Lets also examine the report by the eight people sitting on the beach at Bandar Marang on the NE coast of the Malay peninsula at 1:30AM, who heard a "loud and frightening noise" that "seemed to come from Kapas Island." We all know that sounds reverberate and bounce off large solid objects. What if the eight people on the beach heard an explosive decompression of MH370? (they would have been within hearing distance of waypoint IGARI, and sound carries a long way at night, and through the sky). Let's say an oxygen bottle in the cabin exploded and caused major decompression, and took out a heap of electrical wiring and comms, including the transponder. The crew immediately commenced a left turn to return to KL and initiated a rapid descent. However, hypoxia took over prior to reaching a low level and the crew became unconscious. The aircraft continued to fly in a gentle arc, back over the Malay peninsula, at a steadily reducing height, or at a low height preset by the crew on the AP. In that case, there's a strong possibility the aircraft crashed into the Gunung Leuser National Park - one of the largest, largely unpopulated, mountainous wilderness areas in Northern Sumatra. An aircraft crashing into a high-elevation area of this park at 3:00AM local time would be heard by very few people - and it would disappear into the jungle just as GOL 1907 did. It's starting to become obvious that MH370 did not crash into the sea in the current search areas. Vietnam has scaled back its search, obviously confident the aircraft wreckage is not in its search area. The seas in the search areas have been combed by vast numbers of ships, aircraft and even satellites over 4 days, and nothing has been found. If there was wreckage in the current sea search areas, at least one or two fishing boat crews would have come forward by now. The silence is deafening. The aircraft obviously flew well outside the current search areas. "Gunung Leuser National Park is 150 km long, over 100 km wide and is mostly mountainous. 40% of the park, which is mainly in the north, is steep, and over 1,500 m. 12% of the park only, in the lower southern half, is below 600 metres but for 25 km runs down the coast. 11 peaks are over 2,700 m and the highest point is Gunung Leuser, which 3,466 m high". |
What if?
What if MH370 wanted to perform an emergency landing for whatever reason. Close to IGARI point the crew entered a possible airport to land in their FMS which could be VVCT CAN THO with VOR "TRN", because this one has a 3000m runway which is close to the intended route ahead. But, there is another "TRN" VOR closer by, guess where: TRANG VOR close to the Andaman sea. The crew under severe stress executes the top TRN (closest by) in the FMS and the plane turns immediately to that point. Could this explain the hard left turn after IGARI point towards the Andaman sea?
http://s4.postimg.org/4d8stni21/image.jpg "KUALA LUMPUR: The international search for a missing Malaysian airliner has been expanded into the Andaman Sea, hundreds of kilometres (miles) to the northwest of the original search radius, an official said Wednesday." |
AIMS
The lack of communication etc etc from MH370 is strange. Having worked as ground maintenance on 777's for 15 yrs or so, I can only think that something catastrophic happened to power supply, and L and R AIMS has shut down, without AIMS, pretty much all communication is lost including transponder, and most displays apart from standby instruments will fail..just a thought..guess time will tell..just pray for the passengers and crew.
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10 countries in the SAR operations - Malaysia, Vietnam, U.S., China, Australia, New Zealand, Thailand, Phillipines, Taiwan, and Indonesia.
The array of shipping and aircraft in the search is mind-boggling and must be approaching the largest joint SAR force ever assembled in recent years. BBC News - Malaysia Airlines: How is the search being carried out? |
10 countries in the SAR operations - Malaysia, Vietnam, U.S., China, Australia, New Zealand, Thailand, Phillipines, Taiwan, and Indonesia. |
If indeed the transponder failed, there were comms problem and it was returning or preparing for an approach for return. How is it possible that sophisticated air force like RMAF failed to detect the plane for over 1 hour and flag it as possible incursion? :uhoh:
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Neogen - I think that's what the Malaysians are trying to hide. An embarrassment of major proportions.
A radar operator sighted an unknown radar return, pointed it out to a "chief" - and it was dismissed as a flock of birds. :suspect: Either that - or the "chief" was sound asleep at home, and it was common knowledge he didn't like to be awakened, only to find a flock of birds being reported as an "intrusion". :uhoh: |
Dual TRN FMS waypoints...
I just want to say that Tarzanboy's theory is quite an interesting one upon further reflection. What are the odds that there is a perfectly suitable emergency diversion straight ahead with identifier "TRN", plus another location with identifier "TRN" back near the Andaman sea where the aircraft seems to have flown to instead for no apparent reason?
I must admit, it seems like an easy mistake to select the wrong TRN on the display when they would both be roughly the same distance from the place of last contact. |
Onetrack - or they sighted the radar return, informed the chief, RMAF scrambled the jet and overzealous RMAF .....:mad:
One fact for sure: Malaysian officials have given ambiguous, inaccurate and at times directly contradictory information since the aircraft's disappearance. |
@DWS posted:
ITS now being reported on FOX ( kelley files ) - that 777- BA has had had a request or notice in for change to FBW computer / reporting systems for security reasons- that there IS a common ( wired) link somehow between some of the FBW reporting systems and the inflight passenger entertainment systems- and possibly subject to hacking ! Dont know if this report is factual- but am posting it here to give some people with access to FAA paperwork, etc a chance to look it up. And hopefully to give the moderators a chance to standby for a flood of "it was hacked and is now in area 51 .... or somewhere-" In any case- some factual data on this issue would be appreciated by many on this forum- Special Conditions: Boeing Model 777-200, -300, and -300ER Series Airplanes; Aircraft Electronic System Security Protection From Unauthorized Internal Access |
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