This is a very high-quality article and very close to meeting the GA standards. I don't think it should take long at all to pass GA.
It would be nice to have a better source for the number of islands - no information on the current source is easy to find in either language.
Move the statistics on air carriers and government aircraft above the future projections in the lede.
In the sentence "Indonesian aviation faces numerous challenges, including poorly maintained, outdated, and often overwhelmed infrastructure,[6] the factor of human error, bad weather, haze problems caused by plantation fires, and volcanic ash spewed by numerous area volcanoes that disrupts air transportation", there is the sublist of 'poorly maintained, outdated, and often overwhelmed infrastructure' inside the larger list. You may wish to divide this sentence into two parts, or to use semicolons to divide the larger list.
The lists of how many airports have paved and unpaved runways should be converted into
wikitables.
"In Indonesia, there are 22 commercial scheduled
airlines with more than 30 passengers (AOC 121), and 32 airlines for commercial scheduled airlines with 30 or less passengers and chartered airlines (AOC 135)". Is this more than 30 passengers per flight? What does AOC mean? The citation for that sentence also needs to be formatted into a template.