GENEVA, July 22  -- The chief of the International Air Transport Association (IATA) on Tuesday called for unhampered access to investigate the crash of Malaysia Airlines flight MH17.

Tony Tyler, IATA director general and CEO, said the alleged shooting down of MH17 over eastern Ukraine with 298 people onboard was an "outrage, a hideous crime and an attack against the air transport system which is an instrument of peace."

Tyler stressed that immediate priorities included returning the bodies of the victims to families in a respectful manner. He urged governments to set aside their differences and treat the victims and their families with the dignity they deserve, which includes urgently securing the site.

The IATA chief appealed for the investigation to start quickly and with total freedom and access. "We have heard news of potential progress on both these issues. But promises now need to be turned into reality with actions," Tyler in a statement.

"Malaysia Airlines was a clearly identified commercial jet and it was shot down -- in complete violation of international laws, standards and conventions -- while broadcasting its identity and presence on an open and busy air corridor at an altitude that was deemed to be safe," stated Tyler.

Tyler urged that "no effort should be spared in ensuring that this outrage is not repeated."

He said governments would need to take the lead in reviewing how airspace risk assessments are made, and that the industry would do all that it could to support governments through the International Civil Aviation Organization (ICAO).

He said that in spite of the shocking incident, flying remained safe, and everyone involved in global air transport was fully dedicated to making it even safer.

Malaysia Airlines flight MH17, a Boeing 777, was en route from Amsterdam to Kuala Lumpur when it went down last Thursday in eastern Ukraine with 298 passengers and crew aboard. There were no survivors.