NEW YORK, April 5. /TASS/. EU authorities were worried about Germany’s oversight of airlines long before the Germanwings jet crash in the French Alps, The Wall Street Journal reported on Sunday.

"EU officials said Germany’s air-safety regulator suffered from chronic staffing shortfalls that could undermine its ability to run checks of carriers and crew," WSJ wrote.

In 2011, EU’s Euaropean Aviation Safety Agency placed Germany on its quarterly list of aviation safety alerts. Germany pledged to review personnel resources and staff levels, and was removed from the list. However, later inspections found that not all problems were tackled appropriately. In November 2014, Berlin was once again warned and urged to improve the situation in aviation oversight.

A Germanwings Airbus-320 en route from Barcelona to Dusseldorf crashed on March 24 in mountainous terrain in the department of Alpes-de-Haute-Provence, southern France. All 150 people onboard, including 144 passengers and six crew, died in the crash.

Data retrieved from the second black box confirmed that that co-pilot Andreas Lubitz deliberately crashed Flight 9525.

"The pilot put the plane into descent and adjusted the automatic pilot to speed up the descent," the French air accident investigation agency (BEA) said in a statement.

French prosecutors said after recovering the plane's cockpit voice recorder that Lubitz was suspected of bringing down the Airbus after blocking his captain's re-entry into the cockpit.

Meanwhile, prosecutors in Dusseldorf said that Lubitz had studied suicide methods on the Internet shortly before the crash. German investigators searched the co-pilot's tablet computer and discovered that he had also researched cockpit door security.