US investigators probing the in-flight opening of an Embraer EMB-545’s passenger door have determined that a corroded and jammed door sensor falsely indicated to the crew that it was locked prior to departure.

But the National Transportation Safety Board also points out that there were “no anomalies” preventing the door from closing, latching and locking, and other visual warning indicators – specifically red-green flags in the door – were functioning correctly.

Operational procedures require a pilot to check for green ‘latched’ indications as well as green ‘locked’ indications.

“With the [door] handle in the latched [but not locked] position, the two visual locked indications on the door were partially red, showing an accurate status of the door as not locked,” says the inquiry’s newly-issued final report.

Operated by Partee Aviation the executive jet (N179SP) departed Houston for Big Spring in Texas on 3 October 2022.

The first officer, who was flying, had closed the passenger door but commented about feeling a pressure discomfort in his ears after take-off.

As the aircraft – which had been cleared to 16,000ft – climbed through 5,280ft the crew received a ‘door open’ warning, probably triggered by aerodynamic forces or airframe vibrations displacing the faulty door sensor.

Embraer 545 door incident-c-NTSB

Source: NTSB

While the aircraft safely returned to Houston, the open door inflicted substantial damage

The captain went to check the door, and tried unsuccessfully to push the door handle down towards the locked position.

Some 14s after the captain left his seat, the cockpit-voice recorder captured sounds consistent with the door’s opening in flight. It remained attached to the aircraft.

The captain, upon returning to the cockpit, remarked “several times” – the inquiry mentions that he “screamed” – to the first officer that he had not secured the door, to which the first officer insisted that he had.

Neither of the pilots, nor the two passengers, was injured during the event. The crew turned back to Houston where the aircraft landed, the open door contacting the runway during touchdown. The door and the fuselage suffered substantial damage.

Embraer subsequently issued a service bulletin recommending checks on the door-locked sensor, while also developing a new sensor to reduce jamming risks.