All Indonesian airlines including national carrier Garuda are to be banned from the European Union.
All 51 Indonesian airlines will be banned from the EU
An updated blacklist of unsafe airlines also includes operators from Bulgaria, Moldova, Angola and Ukraine.
Indonesian carriers do not currently fly to Europe, but the ban serves as a warning to consumers not to use these airlines elsewhere in the world.
"European citizens should avoid flying with these carriers," an EU official said. "They are really unsafe."
The last version of the blacklist, published in March, featured 91 airlines, 74 of them from Africa, and most of the rest from Kyrgyzstan.
The new list includes all 51 carriers from Indonesia, eight from Moldova, six from Bulgaria, Angolan carrier TAAG Angola Airlines and Volare Aviation from Ukraine. It will be formally approved on 4 July and published the next day.
The EU also notes that Russia is currently blocking all flights to the EU by four passenger airlines and has placed restrictions on six other companies.
An existing ban on Pakistan International Airlines will also be relaxed to allow specific Boeing 747 and Airbus 310 aircraft to fly to Europe, in addition to its Boeing 777 fleet, which is already regarded as safe.
The new list, decided upon following advice from an EU air safety committee, is expected to be formalised within a week.
Garuda flew to Rome and Amsterdam until 2005, and is planning to resume services to Amsterdam in 2008.
Indonesia's ambassador to the EU, Nadjib Riphat Kesoema, said Indonesian airlines were safe and he hoped the EU would review its decision at a meeting of air safety experts in October.
Series of accidents
"It is our commitment and our determination to have safety in our civil aviation," he told the Reuters news agency.
"We hope that the European Union can also give us the opportunity to improve."
Indonesian airlines have suffered a series of accidents this year.
On Monday, a government safety review promoted Garuda to the country's top safety category, the only airline to achieve that level.
Adam Air was boosted to the second grade, having previously been ranked at the third level.
On New Year's Day an Adam Air jet fell into the sea, killing all 102 people on board.
Some weeks later, another plane broke in half as it landed.
And in March, a Garuda Boeing 737 veered off a runway and burst into flames, leaving 21 dead.