A recording from the cockpit of a cargo plane that crashed into a Texas bay in February suggests the pilots lost control while preparing to land at a Houston airport.

The National Transportation Safety Board says its preliminary review of the audio found that 18 seconds before the recording ends there were “crew communications consistent with a loss of control of the aircraft.” The federal agency does not say why the crew may have lost control.

The Boeing 767 dropped into Trinity Bay killing the three people aboard after losing more than 3,000 feet of altitude in 30 seconds, according to tracking data from FlightAware.com.

Air traffic control had given the crew instructions to land on a runway at George Bush Intercontinental Airport before the plane smashed into the shallow bay about 40 miles (64 kilometers) east of the airport, according to the NTSB.

Investigators are still reviewing the audio and information from the flight’s data recorder. The NTSB cautions its early findings may change.

The two-hour cockpit recording captures the final moments of Atlas Air Flight 3591, which was carrying packages from Miami for Amazon and the US Postal Service. But the NTSB says the audio is difficult to discern at times and investigators have had to use “advanced audio filtering” to make out some of what was said.

The agency says it plans to provide an update from its review of flight data in a few days and will eventually produce a transcript of the cockpit audio.

(AP)