马空军司令：马航客机或曾空中折返

据美联社3月9日报道，军事雷达记录显示失联的波音777号客机消失前或曾折返。

马来西亚空军司令罗德扎利·达乌德表示，雷达记录显示马航失联客机在失踪前有折返迹象，这让MH370航班客机失踪前几分钟的情况更加扑朔迷离。

该客机上共有来自14个国家的227名乘客和12名机组人员，其中包括150余名中国乘客。其于北京时间3月8日00：42从吉隆坡飞往北京，01：20在越南胡志明市管制区与空管部门失去联系，同时飞机雷达信号消失。飞机消失时天气状况良好，飞机处于巡航阶段，并没有发出任何异常信号。

马来西亚航空公司首席执行官称，飞机如果需要折返，飞行员应当与航空公司和空中管制中心取得联系。他说：“但飞机没有发出任何呼救信号或遇险信号，这让我们非常困惑。”

目前大规模海上搜救尚未找到飞机残骸，越南空军在距土珠岛150公里海域发现了两处长达数十公里的痕迹，像是油渍，但并不清楚是否与失联客机有关，附近也未发现任何飞机残骸。

马来西亚航空也告知失踪人员家属，飞机失联已经过去30个小时，希望家属们“做好最坏的心理准备”。

另外，马来西亚官方正在调查失联客机上的4位乘客的身份，包括此前曝出的使用被盗护照登记的2位奥地利和意大利乘客。奥地利和意大利外交部目前均已确认，该两人名字与在泰国报失的两本护照名字一致。

悉尼新南威尔士州航空学院院长杰森·米德尔顿认为此次失事可能是由于恐怖主义或其他违规行为。但澳大利亚麦格理大学反恐怖主义专家、前军事情报局官员克莱夫·威廉姆斯对此持怀疑态度，他称最新国际刑警数据显示，截止到2013年12月13日，全球共有3900万被盗护照。“亚洲这种规模的航班上，总会有那么几个人持有假护照。想想全球有多少护照被偷或丢失，你就会明白，这可能与恐怖袭击有关，但也很可能没有关系。”

Military radar indicates that the missing Boeing 777 jet may have turned back before vanishing, Malaysia's air force chief said Sunday as authorities were investigating up to four passengers with suspicious identifications.

The revelations add to the uncertainties surrounding the final minutes of flight MH370, which was carrying 239 people when it lost contact with ground controllers somewhere between Malaysia and Vietnam after leaving Kuala Lumpur early Saturday morning for Beijing.

A massive international sea search has so far turned up no trace of the plane, which lost contact with the ground when the weather was fine, the plane was already cruising and the pilots didn't send a distress signal - unusual circumstance for a modern jetliner operated by a professional airline to crash.

Vietnamese air force jets spotted two large oil slicks Saturday, but it was unclear if they were linked to the missing plane, and no debris was found nearby.

Air force chief Rodzali Daud didn't say which direction the plane might have taken or how long for when it apparently went off route.

"We are trying to make sense of this," he told a media conference. "The military radar indicated that the aircraft may have made a turn back and in some parts, this was corroborated by civilian radar."

Malaysia Airlines Chief Executive Ahmad Jauhari Yahya said pilots were supposed to inform the airline and traffic control authorities if the plane does a U-turn. "From what we have, there was no such distress signal or distress call per se, so we are equally puzzled," he said.

Authorities were checking on the suspect identities of at least two passengers who appear to have boarded with stolen passports. On Saturday, the foreign ministries in Italy and Austria said the names of two citizens listed on the flight's manifest matched the names on two passports reported stolen in Thailand.

This, and the sudden disappearance of the plane that experts say is consistent with a possible onboard explosion, strengthened existing concerns about terrorism as a possible cause for the disappearance. Al-Qaida militants have used similar tactics to try and disguise their identities.

Malaysian Transport Minister Hishammuddin Hussein said that authorities were looking at two more possible cases of suspicious identities. He said Malaysian intelligence agencies were in contact with their international counterparts, including the FBI. He gave no more details.

"All the four names are with me and have been given to our intelligence agencies," he said. "We are looking at all possibilities."

A total of 22 aircraft and 40 ships have been deployed to the area by Malaysia, Thailand, Singapore, Indonesia, China and the United States, not counting Vietnam's fleet.

Two-thirds of the jet's passengers were Chinese. The rest were from elsewhere in Asia, North America and Europe.

After more than 30 hours without contact with the aircraft, Malaysia Airlines told family members they should "prepare themselves for the worst," Hugh Dunleavy, the commercial director for the airline told reporters.

Finding traces of an aircraft that disappears over sea can take days or longer, even with a sustained search effort. Depending on the circumstances of the crash, wreckage can be scattered over many square kilometers (miles). If the plane enters the water before breaking up, there can be relatively little debris.

A team of American experts was en route to Asia to be ready to assist in the investigation into the crash. The team includes accident investigators from National Transportation Safety Board, as well as technical experts from the Federal Aviation Administration and Boeing, the safety board said in a statement.

Malaysia Airlines has a good safety record, as does the 777, which had not had a fatal crash in its 19-year history until an Asiana Airlines plane crashed last July in San Francisco, killing three passengers, all Chinese teenagers.

Investigators will need access to the flight data recorders to determine what happened.

Some aviation and terrorism experts said revelations about stolen passports would strengthen speculation of foul play even as they also acknowledged other scenarios: a catastrophic failure of the engines or structure of the plane, extreme turbulence or pilot error or even suicide were all possible.

Jason Middleton, the head of the Sydney-based University of New South Wales' School of Aviation, said terrorism or some other form of foul play seemed a likely explanation.

"You're looking at some highly unexpected thing, and the only ones people can think of are basically foul play, being either a bomb or some immediate incapacitating of the pilots by someone doing the wrong thing and that might lead to an airplane going straight into the ocean," Middleton said. "With two stolen passports (on board), you'd have to suspect that that's one of the likely options."

But Clive Williams, a counter-terrorism expert at Australia's Macquarie University and a former military intelligence officer, said he doubted the two stolen passports aboard the flight were related to the disaster. He said latest Interpol data showed there were 39 million lost or stolen passports reported as of Dec. 13, 2013.

"Any flight of that size in Asia would be carrying a couple of people with false passports," he said. "When you think about the number of passports that have been stolen or gone missing around the world ... it could be related, but it's probably not."

Just 9 percent of fatal accidents happen when a plane is at cruising altitude, according to a statistical summary of commercial jet accidents done by Boeing. Malaysia Airlines CEO Ahmad Jauhari Yahya said Saturday there was no indication the pilots had sent a distress signal.

The plane was last inspected 10 days ago and found to be "in proper condition," Ignatius Ong, CEO of Malaysia Airlines subsidiary Firefly airlines, said at a news conference.