Indonesia relies heavily on air transport and has a poor aviation safety record.
On 9 May a Russian Sukhoi Superjet plane crashed into mountains in Indonesia, killing all 45 people on board. In 2009, 24 people died after a military plane, also on a training flight, crashed and caught fire at an airport in West Java.
So 3 crashes in 3 years in what can be a hostile environment supports the accusation of a poor safety record.