In the early days of the search of MH370, when the mainstream media was favouring a terrorism-hijacking scenario or questioning if one of the pilots was suicidal, I put forward an alternative theory – that the loss of the aeroplane might have been the result of an accident. This theory was picked up on the web and went viral. I did not seek or expect such an enormous response: I wrote simply as a pilot with some knowledge of the issues defending two fellow pilots who were being much-maligned and who could not defend themselves.
More than three months have elapsed since the Boeing 777 vanished after taking off from Kuala Lumpur in the early hours of March 8, bound for Beijing. Yet the mystery of how a modern aircraft can disappear from the face of the earth continues to fascinate and appal. In this era, when delivery companies like UPS and FedEx routinely track vehicles via global satellite positioning (GPS), it seems incredible that this passenger jet, capable of auto-landing in total fog, did not carry a device broadcasting its position in real time and independent of all other systems on board. If one good thing comes out of this accident, it will be a new regulation making the fitting of such a device compulsory.
CONFLICT OF INTEREST: Malaysia benefits the most if MH370 remains in a state of confusion
Since the aircraft belonged to Malaysian Airlines and the incident is presumed to have started in Malaysian airspace, the lead nation in the investigation is Malaysia. In my opinion, this is the Achilles heel of the inquiry. The majority owner of Malaysian Airlines Systems (MAS) is PMB, a Malaysian government holding company. MAS has clocked up net losses of $1.3 billion (£766 million) in the past three years.
This is a clear conflict of interest, which has resulted, intentionally or otherwise, in a bungled investigation.
If the bungling is intentional, then might it have something to do with the cargo that MH370 was carrying (more of which later)? Until this matter is resolved, the disappearance will continue to be surrounded by conspiracy theories.
For me, the answer is clear: the one party benefiting from the continuing state of confusion surrounding MH370 is Malaysia.
Did MAS stinge on crucial repairs
The disappearance of this twin-engine wide-body airliner is without parallel in modern aviation, a mystery replete with questions. But what is certain is that something fast and furious occurred on that aircraft as it flew over the South China Sea.
There is always the possibility of design flaw in anything mechanical, and there is an established procedure by which aircraft manufacturers and regulators handle these issues. Service Bulletins (SBs) issued by manufacturers, and Airworthiness Directives (ADs) issued by regulators keep the industry informed. The Boeing 777 has had its share of such notices, and there are two in particular that are relevant to MH370 – one involving a short-circuit in the hose feeding emergency oxygen to the crew, and one warning of possible rupturing of the aircraft pressure vessel due to the mounting of a satellite communications antenna.
The former was responsible for a well-documented accident (fortunately on the ground at Cairo) involving an Egyptair 777. The resultant fire destroyed the cabin and burned a hole through the plane, and would have been catastrophic if it had occurred in mid-air. The satellite antenna issue could also be fatal, tearing the aircraft’s skin and resulting in rapid depressurisation. It is time for the Malaysian authorities to show that checks and modifications regarding these issues and contained in SBs and ADs were complied with.
Cargo remains most controversial issue
But the issue that requires most clarity remains the plane’s cargo. It took almost three weeks for the world to learn that MH370 had been carrying a consignment of lithium-ion batteries. But we do not know for sure how many.
What else of a hazardous nature was being carried? Published cargo records show neither the real shippers nor the real recipients. The international community should demand total transparency from the Malaysians in regard to this. After all, huge resources have been spent by Australia, China, the United States and others on the so-far fruitless search for debris in the Indian Ocean.
Why focus on the pilots?
The US is party to the MH370 investigation for two reasons: American citizens were aboard, and the aircraft was American-built. The FBI has all but cleared Zaharie Ahmad Shah, the flight’s captain, and Fariq Abdul Hamid, his co-pilot, of deliberately causing the disaster.
Sure, the captain may have disagreed with his government on some issues, but that does not make him a suicidal mass-murderer. If making a point was his aim, why did he not nose his aircraft straight towards the Petronas Towers in Kuala Lumpur, two of the world’s tallest buildings and a headline-grabbing target?
His young co-pilot was about to get married and had a wonderful career ahead of him. There is no evidence of either man having been motivated by Islamic extremism.
Massive M'sian govt cover up
In the end, everything comes back to the Malaysian authorities. Criminal and civil liability can be big motivators when it comes to cover-ups.
If crucial maintenance checks – on the bonding of satellite antennae for example – were being delayed by a loss-making airline to save money, we need to know. If dangerous cargo was being carried to augment revenues, we should be told.
The wreckage of MH370 could give us the answers, but we don’t have it. The Malaysians need to come clean.
Doubt over all radar tracks produced by M'sia: Did MH370 really head west?
I will maintain my view that the loss of MH370 was due to an accident until it is proved otherwise. As I stated three months ago in my online post, the crew were almost certainly dealing with a major emergency when they made their unannounced turn to the west.
Why west? Because they were diverting towards the island of Langkawi, on the west coast of Malaysia. Langkawi’s international airport boasts a long runway which is easy to approach, a must for a large aircraft in trouble. The 777’s silence could be accounted for by a sudden major fire that knocked out all its systems, or the crew being distracted by their tasks.
At the time that I proposed my theory, the only radar track produced by the Malaysian military showed the aircraft turning west off its scheduled flight path and tracking towards Penang.
A few days later, the Malaysians produced another track indicating that MH370 overflew Penang before navigating up through the Straits of Malacca. These course alterations were cited as evidence of human intervention, but they could be the result of the autopilot making its way through pre-programmed waypoints – if indeed the aircraft performed these manoeuvres.
Doubt has been cast on all the radar tracks produced by Malaysia in relation to this matter. Maybe MH370 never went west.
Time to hand over to an impartial independent body
Where to search now? There have been sightings from the Bay of Bengal to the Maldives. For the moment, attention remains in the southern Indian Ocean, way to the west of Australia. Mapping of the seabed is expected to be followed by a renewed search in the late summer. That region has been the focus of the search following pings received from MH370 by an Inmarsat communications satellite. But these calculations have been the subject of much controversy.
Only one thing is certain: Malaysia has lost all credibility in regard to the MH370 investigation and should yield control to a competent and impartial authority.
That is why I believe matters should be turned over to Britain’s Air Accidents Investigation Branch. Founded in 1915, it enjoys an unrivalled reputation for thoroughness and independence. Maybe then we will begin to make some progress towards resolving the mystery of the MH370 ghost flight. - The Telegraph
Chris Goodfellow is a retired businessman and former pilot who lives in Florida. He is a graduate of McGill and Cornell universities and a former director of the Canadian Internet Registration Authority
Update: Since this article was published, it has been pointed out that flight MH370's Boeing 777 was not fitted with the satellite antenna involved in one of the Airworthiness Directives mentioned. This Directive was therefore not relevant to flight MH370.
Monday, 16 June 2014 08:10
MH370 was shot down - by MALAYSIA! Former FBI agent's shocking allegation
A week after Malaysia Airlines Flight 370 vanished in mid-flight, hobby pilot and aviation enthusiast Keith Ledgerwood decided to investigate theories related to its disappearance. Armed only with available civilian radar and amateur knowledge, he found unusual coincidences and decided to share them with the world.
His blog post contending that MH370 shadowed another aircraft went viral and is considered one of the more plausible, if dauntingly intricate, alternate theories about what happened to the plane.
Ledgerwood proposed that MH370 didn't fly south, as is the consensus among experts based upon available data. Instead, he says, it headed north and flew in the shadow of another commercial flight, Singapore Airlines Flight 68, which was en route from Singapore to Barcelona at the time. This would effectively cloak MH370’s radar signal and prevent it from being detected, he wrote.
Ledgerwood’s theory is among countless attempts to explain what happened to the Boeing-777 with 239 people onboard. Suspected terrorism, government cover-ups, pilot suicide, mechanical failures and even an alien abduction scenario have all been proposed by observers who range from technical experts to former pilots, government officials and armchair analysts who may or may not have an informed clue. The lack of proof makes it impossible to prove or disprove any of them. Theoretically, anything is possible.
Ledgerwood, a 30-year-old IT professional from Cincinnati who has a pilot’s license and has flown air simulators since he was a teenager, decided to go public with his idea after concluding that no one else had proposed a logical explanation.
“No one in the media, no Malaysian official had published anything up to that point or spoken to the fact that the aircraft was anywhere near the Singapore Airlines flight at the time of its disappearance,” Ledgerwood told International Business Times.
Hijacked and landed in China’s Xingjian province, Kyrgyzstan or Turkmenistan
Soon after he published the blog post, Ledgerwood was being cited in news articles and contacted by experts who wanted to determine the credibility of his theory.
“The theory stayed plausible,” Ledgerwood maintained. His scenario describes how the plane would fly undetected by radar beneath the Singapore Airlines commercial jet -- either controlled by the pilot or co-pilot for presumably criminal purposes -- until it lands in China’s Xingjian province, Kyrgyzstan or Turkmenistan. These locations line up with the Singapore Airline's 7.5-hour flight time and the last known ping emitted by MH370, he said.
He sent his findings to Inmarsat, the satellite communications company that helped triangulate the hourly pings the aircraft sent to its satellites. According to Ledgerwood, the company pulled satellite data from both MH370 and the Singapore Airlines 68 to see whether his theory held up. He says his analysis got shelved when the company used the Doppler Effect and determined that the plane’s flight path most likely headed south and that the Boeing-777 crashed somewhere in the southern Indian Ocean.
For Les Abend, a Boeing-777 pilot who has worked for a major U.S. airline for 30 years (he declined to name the airline), Ledgerwood’s scenario is “total nonsense.” Not only would the Singapore Airlines flight be aware of MH370’s presence using its onboard equipment, but the timing would have to be exact, he said.
Robert Mann, a veteran airline industry analyst with expert knowledge in air traffic control systems, has yet another take. He said it’s possible the MH370 could have shadowed another aircraft of similar size, but that the maneuver would be extremely complex.
Since both of the aircraft’s radar devices were off (for reasons that have yet to be determined), it’s conceivable that the plane could approach another without detection, Mann said.
“It’s, in theory, possible,” he said. “The question is, can you expect a commercial pilot to fly close in trail to another commercial aircraft? It’s at night and formation flying is difficult to begin with in a small aircraft. It’s particularly difficult in a large aircraft where you have trailing wind vortex and other considerations.”
Did passengers die painlessly or in 'terror'
Ledgerwood isn’t the only “amateur” who has authored an MH370 theory. Nigel Cawthorne, a journalist based in Britain, recently wrote a book about the plane’s disappearance in which he outlined many of the conspiracy theories that have emerged.
The book, published less than 11 weeks after MH370 vanished, has been criticized as insensitive, premature and conjectural. Cawthorne has sought to defend himself against these claims, including on an Australian television show on which the co-host read a sentence from the book that asked, “Did they die painlessly unaware of their fate or did they die in terror in a flaming wreck crashing from the sky at the hands of a madman?” Cawthorne conceded the passage was “colorful.”
In an email to IBTimes, Cawthorne said the timing of the book’s publication was up to the publishers and that many of his detractors are guilty of some of the same accusations made against him.
“The criticism of insensitivity was leveled at me by TV presenters who are happy to run the story on their shows, which reach a far wider audience than I could ever hope to with my book. They certainly showed no sensitivity to the feelings of the families,” he said.
Another article objected to the book’s government cover-up theory in which the plane was shot down in a U.S.-Thai military exercise.
“The book did not say that. It simply raised it as one of the theories that was doing the rounds,” Cawthorne said. “I have taken all the theories and knocked them down. In my experience, governments can barely run a candy store, let alone organize a grand conspiracy. I don't believe that there are dark forces behind the scenes pulling the strings. People in power just aren't that competent.”
'Malaysia shot down its own plane'
Jonathan Gilliam, a former FBI special agent and federal air marshal, disagrees with Cawhorne’s assessment that governments are incapable of such a cover-up. “One thing that I definitely suspect as a possibility is that Malaysia shot that plane down,” Gilliam said.
His hunch stems from one of the initial reports that described MH370 pilot Zaharie Ahmad Shah as a supporter of Anwar Ibrahim, the leader of the opposition to Malaysia’s ruling party. Ibrahim was convicted on sodomy charges hours before the doomed flight departed, and the pilot had been present in the courtroom.
“This plane was flown by a guy who just left a sentencing of an opposition to the standing political party or administration in Malaysia. He goes from there and gets on a plane. He takes that plane, he flies and turns around and flies back at Malaysia,” Gilliam said. In such a scenario, he said, the Malaysian military would have scrambled jets to intercept it.
Gilliam cited the very lack of evidence as evidence: In his view, government officials have intentionally not located the wreckage of the plane because they shot it down.
As for reports that pings were heard from the plane’s black box during the search off the coast of Australia, which were later determined to have come from a man-made device, Gilliam argued such sounds could easily be replicated as a distraction. Pingers can be bought from aircraft suppliers and are enabled by placing them in water, he said, adding, “It wouldn’t have been difficult to throw one of those off a ship in 20,000 feet of water and cause hysteria.”
There were also flaws in the search effort itself, Gilliam said. If the plane was shot down as he posited, the search area would be located near Malaysia -- specifically off the country’s western coast.
“When the plane turned, it went back across Malaysia and north. That’s one of the only places where they never really searched,” Gilliam said. “They searched in between Malaysia and Vietnam. They searched all the way down by Australia but they never searched heavily the southwest coast of Malaysia. This is another stretch but I think it’s another plausible theory no one has looked at.”
Gilliam added that the aircraft involved in the aerial search weren't used to their full capacity. That is, since the planes had to fly more than 1,000 miles each way to reach the search area, they didn’t have enough fuel to stay in the air for long before heading back to land. Gilliam said this wasn’t necessary -- that the planes have the ability to be refueled midair, and doing so would have given them more time to survey the area.
“To have planes flying 2,000 miles and landing is kind of ridiculous when you could have sent a refueling plane there to keep them on station all the time,” he said.
Gilliam stops short of speculating about a government cover-up -- though if his theory is correct, it would mean the government covered up having downed the plane -- and says he understands why countries may need to conceal certain kinds of information.
“I’m not saying governments made the plane disappear. If they had to shoot it down and want to keep [Malaysia] from being attacked from China or causing an international incident, I can see some things being taken care of. That is as big of an assumption as saying the plane went north into Pakistan or Afghanistan,” he said.
Abend, the pilot, maintains that the plane likely crashed due to a mechanical failure, but says he once believed the plane might have gone down in a jungle as opposed to the ocean. It was only after he spoke to one of the VPs at Inmarsat that he became convinced the aircraft crashed in water, as the satellite company claims.
“I walked through all nefarious scenarios,” he said. That includes those in which the pilots were involved in terrorism, he added.
“The co-pilot was 27 years old, sitting right-seat in one of the biggest jumbo jets in the world. He likes his checks. He’s got the world going for him. Doesn’t make a lot of sense why he would take this airplane and ruin a great career to make a statement. There was no indication of this,” Abend said.
Then there were reports that Captain Zaharie Ahmad Shah’s wife left him, which may have led him to commit suicide, one of his pilot friends who spoke on the condition of anonymity told UK’s Express. Other suicide mission scenarios point to how one of the pilots may have steered the jetliner into a remote part of the world on purpose so their family members could still collect life insurance.
“If they never find the plane, they can’t call it suicide,” Rep. Pete King (R-LI), chair of the House Homeland Security Subcommittee on Counterterrorism and Intelligence told the New York Post.
This is what happened with EgyptAir flight 990 in 2002 when the flight’s co-pilot deliberately killed 217 passengers on board. An investigation found it was an act of revenge after he was reprimanded by the airline for sexual misconduct. His punishment forbade him from flying U.S. routes, which carry extra pay. A black box recording revealed how co-pilot Gamil el-Batouty took control of the cockpit, forced the plane into a dive, then soared it back up to 24,000 feet. The aircraft lost power and broke apart from the stress.
Pilot suicide theory unlikely
Abend says there’s no proof that the MH370 pilots were emotionally unstable in any way.
“If you take the captain and rumors about the fact that maybe his marriage wasn’t going great or he had girlfriends -- it’s all alleged,” he continued. “The information released from the FBI shows there’s no indications there would be motivation for this man to commit suicide or a nefarious act. It just doesn’t make sense for this man to take the airplane towards where? The middle of the ocean? For what purpose?”
As for the theory that one or both of the pilots committed suicide, Abend says that while it may be possible, he discounts it.
“If you’re going to commit suicide, there’s a hell of a lot of better ways to really make a statement. Why take 238 other people with you on this ride? It just sounds way too insane for me -- if you take it from the perspective of the crew doing it.”
Abend doesn’t believe a pilot could easily turn off the plane’s transponder – its secondary radar, which transmits the flight speed, identification tag and direction to air traffic control -- to mask its flight path. To do so would require personally descending into the plane’s electronic bay beneath the first class cabin and manually shutting it off, and as a pilot himself, Abend said he would have no idea how to do that.
“I don’t even know where it is. That’s why in the back of my head I’m always saying something mechanical happened,” he said.
For Abend, one of the theories that may fit all the facts is a fire caused by the cargo on board. A cargo manifest for MH370 included 5,440 pounds of batteries.
“To the best of my knowledge they were loaded in the forward baggage compartment. You can access the forward baggage compartment from the EB (electronics bay) compartment. If a fire were to ignite, who knows what it would have burned through,” he said.
Abend isn’t the only pilot to propose a fire-based theory. Chris Goodfellow, an instrument-rated Florida pilot, wrote a blog post that assumed an electrical fire onboard. In his explanation, the plane’s sudden 90-degree turn left was intended to direct the jetliner to a runway on the island of Langkawi after a fire broke out in the cockpit. To stop the fire, the pilots pulled the circuit breakers, which would explain why both radar systems were turned off. The scenario ends with the men unconscious and the plane flying “on deep into the south Indian Ocean” until it ran out of fuel and crashed.
Goodfellow’s theory has been questioned, however, because the plane made two other sharp turns that would've been impossible if the pilots were unconscious. There was also an electronic ping detected by the Inmarsat satellite that placed the plane on two arcs that wouldn't take it near Langkawi without human intervention, Slate’s Jeff Wise pointed out.
Satellite data has allowed amateur investigators to map the possible paths of MH370. International Business Times/Hanna Sender
As outsiders continue to speculate on what happened to MH370, the passengers’ families have begun to doubt the official findings. On June 9, several relatives started a crowdfunding campaign to raise $5 million to spend on an independent investigation to find answers.
"The official investigation being run by governments and agencies has failed to find the plane, due to either incompetence or obfuscation. We must work together to ensure the truth is found,” Sarah Bajc, the girlfriend of passenger Philip Wood, said on the campaign’s website, which has raised more than $24,000 so far. “On behalf of the 3.1 billion people who fly every year, we must find the truth and bring those accountable to justice. We must also prevent this from ever happening again." - IBT
Star Online .....
Published: Tuesday June 17, 2014 MYT 11:00:00 AM Updated: Tuesday June 17, 2014 MYT 11:47:04 AM
MH370: Search yet to target most likely crash site, says Inmarsat
LONDON: The search for missing Malaysia Airlines (MAS) flight MH370 is yet to target the most likely crash site, having been distracted by what is now believed to have been a bogus signal, British company Inmarsat claimed Tuesday.
Inmarsat's scientists told the BBC's Horizon programme that they had calculated the plane's most likely flight path and a "hotspot" in the southern Indian Ocean in which it most likely came down.
The flight lost contact on March 8 en route from Kuala Lumpur to Beijing with total of 239 passengers and crew on board.
Hourly pings sent by the plane were received by Inmarsat's spacecraft, leading scientists to calculate its likely path.
Australian naval vessel Ocean Shield was dispatched to investigate, but before reaching the likely site, began to detect a signal that it believed was coming from the plane's black box, Inmarsat told the BBC programme.
Two months were spent searching 850 sq km of sea bed north west of Perth, but the source of the "pings" was not found and a submersible robot found no evidence of the airliner.
"It was by no means an unrealistic location but it was further to the north east than our area of highest probability," Chris Ashton at Inmarsat told Horizon.
Experts from the satellite firm modelled the most likely flight path using the hourly pings and assuming a speed and heading consistent with the plane being flown by autopilot.
"We can identify a path that matches exactly with all those frequency measurements and with the timing measurements and lands on the final arc at a particular location, which then gives us a sort of a hotspot area on the final arc where we believe the most likely area is," explained Ashton.
After coming under criticism from relatives over the futile search, Malaysia's civil aviation authority and Inmarsat last month decided to release the raw data.
However, its complexity has led to few independent conclusions being drawn about the likely crash site. – AFP
Published: Sunday June 15, 2014 MYT 7:30:00 PM Updated: Sunday June 15, 2014 MYT 7:41:23 PM
MH370: Families remember missing loved ones on Fathers' Day
SUNGAI BULOH: It has been 100 days since Malaysia Airlines flight MH370 went missing, and the occasion was made more even poignant as about 10 family members of passengers and crew aboard the Boeing-777 gathered on Fathers' Day in memory of the patriarchs on board and the families they left behind.
The families - strangers but united in grief and solidarity - penned heart-felt messages to their loved ones on pieces of coloured paper, folded them into paper planes and arranged them to form the words 'MH370' during the event.
Among the group was 34-year-old Intan Maizura Othman, who came with her four-year-old daughter Iman and 28-day-old son Muhammad, to remember her husband Mohamad Hazrin Mohamed Hasnan.
"It's a tiring task that I have to do alone now. Taking care of my two kids, waking up alone and just coping with all this. It has been challenging.
"I'm okay, but now that it has come to 100 days, it's getting more painful and tiring. I've grown restless of just waiting," Intan Maizura told The Star at the Kolej Perkembangan Awal Kanak-kanak on Sunday.
She said that Mohamad Hazrin, one of the cabin crew on the flight, was her partner in everything at home - from caring for the family to household chores.
"It's excruciating missing him," she added.
For Nicolette Gomes, the worst part of not having her father, MH370 in-flight supervisor Patrick Francis Gomes around, was to see how much her three-year-old son, Raphael, misses his grandfather.
"The most painful thing is my son not having his grandpa to play with him. Last time it was badminton and football, but now its nothing.
Raphael, three, grandson of MH370 in-flight supervisor Patrick Francis Gomes, cries as he releases a balloon to mark the 100 days since the airplane's disappearance. With him is his aunt Michelle Gomes. Starpix/AZMAN GHANI
"My son still talks about him at night, sometimes he'll say 'Grandpa's coming back tonight! 10 o'clock!' And then I just get chills and goosebumps. I do hope that comes true though," said Gomes, 27.
The event was organised by Voice370, a next-of-kin association of around 205 families of the MH370 passengers, which aims to 'seek the truth' behind the incident.
Published: Sunday June 15, 2014 MYT 3:16:00 PM Updated: Sunday June 15, 2014 MYT 3:47:28 PM
MH370: MAS hopes for answers
PETALING JAYA: Malaysia Airlines conveyed its grief to the families of those on board the MH370 plane and hoped for answers that might aid in disclosing what actually happened to the missing aircraft.
The airlines' Group Chief Executive Officer Ahmad Jauhari said that the thoughts and prayers of the staff of MAS remained with the families of the 239 passengers on board the missing Boeing 777.
"The families have been on our minds throughout the last 100 days, and will continue to do so as we feel their pain.
"We miss our colleagues and friends on board MH370 and we continue to hope and seek answers that will bring us closer to finding out what happened to MH370," he said in a statement on Sunday.
Flight MH370 disappeared en route from Kuala Lumpur to Beijing on March 8. It was inexplicably diverted and is believed to have crashed in the southern Indian Ocean.
An extensive search for the plane involving 26 countries has so far failed to unearth any wreckage.
Jauhari added that Malaysian Airlines would like to thank the Governments and various agencies of Malaysia, Australia and China, and the many nations joined in the search for MH370.
“Malaysia Airlines continues to support the search operations, continues to support the next-of-kin and continues to keep in touch.
”It has been the longest and most painful 100 days in Malaysia Airlines’ history,” he said.
CANBERRA, Australia — Australia plans to resume searching for Malaysia Airlines’ missing Flight 370 to the southwest of the area in the Indian Ocean where the seafloor was scanned in detail last month, Australian officials said in interviews over the last five days.
The shift to the southwest reflects analyses of a series of electronic “handshakes” between the missing Boeing 777-200 and a satellite operated by the London-based company Inmarsat in the hours after the plane vanished before dawn on March 8 during a flight from Kuala Lumpur, Malaysia, to Beijing with 239 people aboard.
The satellite data, suggesting that the aircraft turned south across the Indian Ocean after skirting the northern tip of the Indonesian island of Sumatra, remains the best lead that investigators have in trying to find the plane, said Angus Houston, the retired chief of the Australian military who is overseeing the search.
“We’re going to have to go deep and do a comprehensive look at the ocean floor,” he said, later adding, “The handshakes are the most robust information we have at the moment.”
The Australian Transport Safety Bureau hired a private company, Fugro Survey, on June 10 to conduct a three-month survey of the ocean floor along the arc of possible final locations derived from the satellite data. The bureau is also seeking tenders by the end of the month for a commercial contractor to deploy a towed deep-sea submersible to scour the seafloor; Mr. Houston said that the towing operation would not need to wait for the completion of the undersea mapping but could start this summer.
Australia’s own long-range, over-the-horizon radar, known as the Jindalee Operational Radar Network, was not focused on the area where the plane apparently flew and did not detect it, he said. Investigators have also not gleaned any useful clues, he said, from an undersea thud detected by acoustic researchers at Curtin University, near Perth, Australia, that roughly coincided with the time when the plane stopped its electronic handshakes and appears to have run out of fuel.
An Australian vessel, the Ocean Shield, did an exhaustive search last month of a small section of seafloor in the northeast half of the arc of possible final locations for the plane. The search was conducted after the ship detected sounds there that were initially interpreted as locator pings from the aircraft’s so-called black boxes, sounds that were later reanalyzed and found not to be the pings.
Chris McLaughlin, an Inmarsat vice president in London, said Tuesday in a telephone interview that the satellite company did not fault searchers for pursuing those signals, which were detected in April to the northeast of the zone identified by Inmarsat’s calculations.
“The Inmarsat model indicated a more southerly reach for MH370 than the earlier pickup of pings appeared to suggest,” Mr. McLaughlin said. “Four other independent analyses of the data,” conducted by experts at Boeing, the French electronics group Thales and investigators in Australia and Malaysia, “have also indicated a more southerly position, closer to the seventh arc” calculated from the final signal Inmarsat’s satellite received from the plane, he said.
“So we believe the next stage of the search will be concentrated around the outcome of this data,” Mr. McLaughlin said.
On Tuesday, the BBC quoted officials at Inmarsat who said that while Australia had understandably paid considerable attention to the detected sounds, Inmarsat’s modeling of the satellite handshakes had long showed the highest-probability zone for the aircraft’s final location as lying farther to the southwest.
But Inmarsat said in a statement on Tuesday, “Because there are many uncertainties due to the lack of aircraft performance and tracking data, a specific final location in the Southern Ocean cannot be identified.”
Australian officials said that their next priority was to map the ocean floor in enough detail that the deep-sea submersible could be safely towed for long distances at a fairly brisk speed in the coming months with little risk that it will slam into previously undetected seamounts.
Australia has no plans for any further searches from the air for floating debris, having concluded that any debris would have sunk by now or would have spent so much time in the water that it would no longer be recognizable as having come from the plane. “After a period of time, nearly everything sinks, including seat cushions and so on, because they become so waterlogged,” Mr. Houston said.
When an Air France flight crashed off the coast of Brazil in 2009, considerable debris was visible on the ocean’s surface for the first few days, but nothing was left on the surface by the 16th day, and by the 26th day the visual search was halted.
In the early days of the search for the Malaysia Airlines plane, one of the worries was that the plane might have landed on a smooth patch of sea somewhere and then sunk, in which case it might have left no floating debris for airborne searchers to find.
But now the possibility, however small, that the plane might have sunk intact is actually the best-case scenario for searchers. An intact aircraft would be less difficult to find on the vast expanses of the ocean floor than one that had broken into many pieces upon hitting the water.
Such pieces would have descended at different rates and in different directions based on their size, shape and water resistance as they glided or tumbled through water as deep as six kilometers, or nearly four miles.
“We could be confronted with a very dispersed debris field,” Rear Admiral Trevor Jones of the Royal Australian Navy said in an interview on Monday.
A further worry has to do with the topography of the seafloor. When the Air France jet crashed, it came to rest on a fairly level sandy plain at the bottom of the Atlantic Ocean, which facilitated recovery of both black boxes: the cockpit voice recorder and the flight data recorder.
By contrast, sizable areas of the Indian Ocean seafloor where the plane might be located are crisscrossed with hills and ravines and with silt dozens of meters deep in some places. One of the concerns, Australian officials said, is that the black boxes may have plunged deep into the silt, even as lighter articles like clothing may have drifted down slowly and settled on the silt’s surface.
Deep-sea submersibles like the United States Navy’s Bluefin-21, which the Ocean Shield towed last month, have sonar that can penetrate light silt suspended in the water at the ocean floor but may not be able to penetrate thick layers of denser silt.
Australian officials and oceanographers say that silt drifting down on the debris is very unlikely to cover it up in the months and years to come. The rate of deposition is extremely slow, as little as one or two micrometers a year in some areas, a tiny fraction of the thickness of a human hair.
Deposition may be a little faster in the more southerly areas now slated to be searched, as upwelling cold water may sustain more life in the ocean waters above. But the rate of deposition still should not be fast enough to bury debris, said Robin Robertson, an oceanographer at the Australian Defense Force Academy here in Canberra.
Group Captain Craig Heap, the Royal Australian Air Force officer who oversaw the airborne search of large swaths of the Indian Ocean in late March and through April, said that aircraft from Australia, China, Malaysia, New Zealand, South Korea and the United States had logged about 3,000 hours of flying time during the search for debris, including nearly 900 hours of flying over remote areas of ocean where the plane might have come down.
“We’re still very disappointed, and always will be, that we didn’t find anything,” he said, while adding that the search had nonetheless been unusual in producing cooperation among military aviators from China, Japan and South Korea — countries that have had considerable frictions lately over air and maritime sovereignty issues in the East China Sea.
Mr. Houston expressed optimism that the missing plane would eventually be found. But other Australian officials voiced worries that the combination of silt on the ocean floor and the dispersion of debris and the uncertainties about the final flight path may not make it feasible for years, if ever, to find the aircraft and recover its black boxes.