Cracking and corrosion
Months before the Malaysia Airlines jet vanished, US regulators had warned of a "cracking and corrosion" problem on Boeing 777s that could lead to a mid-air breakup and drastic drop in cabin pressure.
"We are issuing this AD (Airworthiness Directive) to detect and correct cracking and corrosion in the fuselage skin, which could lead to rapid decompression and loss of structural integrity of the airplane," the Federal Aviation Administration said.
It had circulated a draft of the warning in September, issuing a final directive on March 5, three days before MH370 disappeared.
In Malaysia, frustrations were boiling over with the country's active social media and some press outlets turning from sympathy for the families of relatives to anger over the fruitless search.
"The mood among Malaysians now is moving from patience... to embarrassment and anger over discrepancies about passengers, offloaded baggage and concealed information about its last known position," Malaysian Insider, a leading news portal, said in a commentary.
Twitter users took aim at the web of contradictory information that has fuelled conspiracy theories.
"If the Malaysian military did not see MH370 turn toward the Malacca Strait, then why the search? Who decided to look there and why?" one comment said.
The anger was compounded by a report aired on Australian television of a past cockpit security breach involving the co-pilot of the missing jet.
Malaysia Airlines said it was "shocked" over allegations that First Officer Fariq Abdul Hamid, 27, along with a fellow pilot, violated airline rules in 2011 by allowing two young South African women into their cockpit during a flight.