The black boxes recovered from the remains of AirAsia Flight QZ8501 seemed to indicate that terrorism was not a factor in bringing the plane down, according to Indonesian investigators. Now an Indonesian official says that the plane climbed fast before it crashed.

CBS News reported that Indonesia's transportation minister thought the plane flew at an "abnormally high rate," then suddenly disappeared from radar.

"Transport Minister Ignasius Jonan told Parliament on Tuesday that radar data showed the Airbus 320 was climbing about 6,000 feet a minute - an unusually rapid rate - before it disappeared on Dec. 28," CBS News reported.

Based on their final contact with Indonesian air-traffic controllers, the pilots of AirAsia Flight 8501 requested to climb from 32,000 feet to 38,000 feet to avoid inclement weather. However, CBS News reported that their request was denied due to heavy air traffic.

No distress signal was sent out before the plane crashed, according to CBS News. The plane disappeared four minutes later after their request to climb to a higher altitude was rejected.

According to Jethro Mullen and Rene Marsh of CNN, audio recordings from the cockpit of Flight 8501 did not have any sounds of gunfire and explosions. Both black boxes, which include the cockpit voice recorder and flight data recorder, were recovered from the depths of the Java Sea last week.

"The voice from the cockpit does not show any sign of a terrorist attack," Andreas Hananto, an investigator at Indonesia's National Transportation Safety Committee, said. "It is only the pilot, sounding very busy."

Hananto added on Monday that "no threats" were heard in the recordings.

"We didn't hear any voice of other persons other than the pilots," investigator Nurcahyo Utomo said.

According to Jane Onyanga-Omara of USA Today, Utomo also said that nothing heard so far indicated that pilot suicide played a role in the crash. He described the progress made in obtaining information from the black boxes.

"So far, we've managed to transcribe only half of (the cockpit voice recorder) because there are so many noises," Utomo said. "We hope to complete it in a week."

Ahmad Pathoni of the Los Angeles Times reported that investigators did not reveal what was said in the plane's final moments. However, a full transcript of the cockpit recordings is not yet completed.

"The rule is that if we find indications of a crime, we will hand over the investigation to the police," Nurcahyo said.

Pathoni reported that the committee's lab in Jakarta is also examining the flight data recorder. Investigators noted that a preliminary report into the crash would be released on Jan. 28.

According to CNN, the cockpit voice recorder captures all noises made on the flight deck. The Los Angeles Times noted that the flight data recorder collects information on the aircraft's electronic systems during a flight.

AirAsia Flight 8501 went down in the Java Sea on Dec. 28 while flying between Surabaya, Indonesia and Singapore, killing all 162 passengers and crew on board. Bad weather is still blamed for the crash, and USA Today reported that a total of 53 bodies have been recovered so far.