US investigators have confirmed that elevator trim cables on a Convair 580 freighter had been reversed before the aircraft crashed in Ohio last September with the loss of all three occupants.

The aircraft, operated by Air Tahoma, had undergone maintenance before the 1 September flight, including disconnection, rigging and reconnection of all flight-control cables in the empennage.

"On-site inspection of the accident airplane revealed that the elevator trim cables were reversed," says the National Transportation Safety Board in an update to the inquiry.

"As a result, when the pilot applied nose-up trim, the elevator trim system actually applied nose-down trim."

It also points out that the flight-data recorder did not contain a record of the accident flight. The NTSB says the pilots "skipped" activation of this recorder while running through the checklist.

The 52-year old twin-engined aircraft, which had logged almost 72,000 hours, had taken off from Columbus' Rickenbacker Airport, on a short flight to Mansfield, when the crew immediately attempted to return. It failed to reach the runway and crashed into a cornfield.

In its update the NTSB states that an inspector did not, as was required, sign off cards for numerous checks during the aircraft's last phase inspection in August 2008. Among the items included in these checks was the crucial connection of elevator servo trim-tab cables.

After the inspection the aircraft did not fly until the fatal departure. The flight lasted just 2min 40s, during which the cockpit-voice recorder showed the captain repeated the word 'pull' about 27 times while the pilots apparently battled in vain to trim the aircraft.

US FAA regulators revoked Air Tahoma's operating certificate following a review in the wake of the crash.

Source: Air Transport Intelligence news