Sub makes 2nd dive to search for Malaysian plane 
| Relatives of Chinese passengers on board the missing Malaysia Airlines 370 walk out from a video-conference with Malaysian officials in protest at the difficulties of communications in Beijing, China, Wednesday, April 16, 2014. A robotic submarine looking for the lost Malaysian jet continued its second seabed search on Wednesday as up to 14 planes were to take to the skies for some of the final sweeps of the Indian Ocean for floating debris from the ill-fated airliner. | 
     PERTH, Australia 
    (AP) -- As a robotic submarine dived into the ocean to look for lost
 Flight 370, angry Chinese relatives stormed out of a teleconference 
meeting Wednesday to protest the Malaysian government for not addressing
 them in person.
The Bluefin 21 sub surfaced 
early for the second time in as many missions, this time after 
experiencing technical difficulties. It was sent back into the water 
after its data were downloaded but there's been no sign of the plane, 
according to the search coordinator.
As the 
search continued, more than 100 relatives of Chinese passengers on the 
plane walked out of a teleconference meeting with senior Malaysian 
officials, an act of defiance over a lack of contact with that country's
 government and for taking so long to respond to their demands.
The
 family members had gathered in a meeting room at a Beijing hotel where 
Malaysia Airlines had provided lodging and food. But they stood and 
filed out shortly before the call with Malaysia's civil aviation chief, 
Azharuddin Abdul Rahman, and others as it was about to start.
"These
 video conference meetings often don't work, the sound stops and it's 
constantly disrupted. Is that how we are going to communicate?" said 
Jiang Hui, one of the family members, after the walkout. "Do they need 
to waste our time in such a way?"
Jiang said 
the Malaysian government had not met demands the relatives had presented
 to them weeks ago in Malaysia - an apology for the way they've handled 
the matter along with meetings with the Malaysian government and airline
 officials. They also have requested to sit down with executives from 
Boeing and Rolls-Royce, the manufacturer of the plane and its engines.
The
 Boeing 777 vanished March 8 with 239 people on board while en route 
from Kuala Lumpur, Malaysia to Beijing. Radar and satellite data show it
 flew far off-course for an unknown reason and would have run out of 
fuel over the southern Indian Ocean west of Australia.
A
 ship-towed device detected four signals underwater that are believed to
 have come from the airliner's black boxes shortly before the beacons' 
batteries died. The sounds helped narrow the search area to the waters 
where the Bluefin 21 is now operating.
The 
U.S. Navy's unmanned sub cut short its first mission on Monday because 
it exceeded its maximum operating depth of 4,500 meters (15,000 feet). 
Searchers moved it away from the deepest waters before redeploying the 
sub to scan the seabed with sonar to map a potential debris field.
On
 the ocean surface, up to 14 planes and 11 ships were searching a 
62,000-square-kilometer (24,000-square-mile) patch of sea about 2,200 
kilometers (1,400 miles) northwest of Perth on Wednesday. The surface 
search is expected to end soon as not a single piece of debris connected
 to the plane has been found.
Investigators 
are also waiting on test results from an oil slick found about 5,500 
meters (3.4 miles) from where the underwater sounds were detected.
In
 addition to finding the plane itself, investigators want to recover the
 black boxes in hopes the cockpit voice and flight data recorders 
contain answers to why the plane lost communications and flew so far 
off-course before disappearing.