Report: Controllers Cleared Superjet 100 Below Safe Altitude

Indonesian investigators focus on controller errors before crash.

Investigators trying to determine what caused the deadly crash of a Sukhoi Superjet 100 in the jungle mountains of Indonesia say controllers cleared the airplane below the minimum safe altitude for the area minutes before the jet slammed into a mountain shrouded in low clouds.

Sukhoi had planned a 30-minute demonstration flight on May 9 for journalists and airline executives. The twinjet departed Jakarta’s Halim Perdanakusuma Airport and was initially cleared to 2,000 feet before being issued a climb to 10,000 feet. After being handed off to Jakarta Approach Control – and just five minutes into the flight – the crew of the Superjet 100 asked to descend to 6,000 feet and requested a series of right orbits.

Controllers approved the request despite the fact that the minimum safe altitude for the sector was 6,900 feet. The route chosen for the flight was not on a published airway, and the minimum off-route altitude for the area was higher still, at 13,200 feet, according to Indonesia’s National Transportation Safety Committee, which is leading the crash investigation.

The airplane crashed into the side of Mount Salak 22 minutes into the flight an altitude of 6,000 feet. All 45 on board were killed.