Warning systems failed on both an executive jet and a commercial airliner that crashed over the Amazon in September, killing 154 people in Brazil's worst air disaster, an Air Force investigator said Thursday.

The executive jet also was flying 1,000 feet higher than what its flight plan called for, putting it on a collision course with the airliner, Col. Rufino Antonio da Silva Ferreira said at a news conference.

In the Sept. 29 crash, the Gol Airlines Boeing 737-800 plunged into Brazil's dense jungle, killing all 154 people aboard. The Legacy landed safely with all seven people aboard unharmed, and its two American pilots have been barred from leaving Brazil. They deny wrongdoing.

Ferreira said the executive jet, a Brazilian-made Legacy owned by ExcelAire Service Inc. of Ronkonkoma, N.Y., "remained at 37,000 feet until the moment of collision." The plane's flight plan said it should have been flying at 36,000 feet, he said.

ExcelAire has denied their pilots violated instructions. Lawyer Robert Torricella said the Legacy was cleared by air traffic controllers to fly at 37,000 feet all the way to the northwestern city of Manaus in the Amazon jungle — even though odd-numbered altitudes are reserved internationally for southbound flights.

"The flight plan was cleared by air traffic control for the Legacy to fly at 37,000 feet to Manaus," he said by telephone. "The (pilots) never received a contrary order."

Ferreira said neither crew saw the other plane coming.

"No one saw anyone," he said. "No one tried evasive action."

Authorities have seized the passports of the American pilots of the Legacy so they can't leave the country. Prosecutors have said that Joseph Lepore, 42, of Bay Shore, N.Y., and Jan Paladino, 34, of Westhampton Beach, N.Y., could be charged with involuntary manslaughter if they are found responsible for the crash.

The Legacy flew past Brasilia at 37,000 feet and "there is no record of a request ... to the control tower to change altitude," a report issued by Ferreira said, maintaining that the plane's flight plan called for it to be at 36,000 feet.

The planes collided at 37,000 feet over the Amazon jungle state of Mato Grosso, and the Boeing went into a nosedive and crashed in the jungle.

"The crash was violent. It disintegrated," Ferreira said.

There also was no sign that either plane saw the other coming and tried evasive action, he said.

Ferreira said he had not interviewed the air traffic controllers and was waiting for a technical report on the condition of the transponders, devices that signal a plane's presence and altitude.

The two American pilots were interviewed and were "cooperative," Ferreira said.

ExcelAire said in a statement that the U.S. pilots union and their international umbrella federation are calling for the release of the two.

"Thus far, only contradictory facts, rumor and unsupported allegations have been forthcoming from Brazilian government officials," the International Federation of Air Line Pilots' Associations, which represents more than 100,000 airline pilots in more than 95 countries, said in a statement.

The federation "calls on the Brazilian authorities to expedite the conclusion of an independent technical investigation into (the crash) ... and that these pilots be allowed to return to their homes forthwith."

Ferreira said "it is not the purpose of this activity to apportion blame or liability," adding that the investigation could take 10 months to conclude.