Alliance E190 at Launceton on Apr 15th 2025, slat fail and other indications

Last Update: January 16, 2026 / 14:45:39 GMT/Zulu time

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Incident Facts

Date of incident
Apr 15, 2025

Classification
Report

Airline
Alliance Air

Flight number
QF-1811

Departure
Sydney, Australia

Destination
Launceton, Australia

Aircraft Registration
VH-UZD

Aircraft Type
Embraer ERJ-190

ICAO Type Designator
E190

An Alliance Airlines Embraer ERJ-190 on behalf of Qantas, registration VH-UZD performing flight QF-1811 from Sydney,NS to Launceton,TS (Australia) with 95 passengers and 4 crew, was on approach to Launceton when the crew received multiple caution messages including "SLAT FAIL" and initiated a missed approach. After completing the relevant checklists the crew decided to divert to Melbourne,VI (Australia), the longest runway available in the area, and landed safely on Melbourne's runway 34 about 75 minutes after the go around.

On Jan 16th 2026 the ATSB released their final report concluding the probable causes of the incident were:

- During scheduled maintenance, the locking bolt for the left outboard slat torque tube was not passed through the hole in the actuator’s splined shaft as the torque tube had been incorrectly positioned. The aircraft was released from maintenance, and 50 flights later, the torque tube disconnected, causing the slat system to fail.

- Both licensed aircraft maintenance engineers inspecting the left outboard slat torque tube did not identify that it had been incorrectly assembled.

The ATSB analysed:

Incorrect fitment of actuator torque tubes

When the torque tube for the left wing slat number 4 outboard actuator was refitted to VH-UZD in November 2024, it had not been positioned far enough onto the actuator’s splined shaft for the locking bolt to secure it in place. After re-entering service and conducting 50 flights, the torque tube disengaged from the actuator, and the slat system failed. Protection systems ensured the safety of flight was minimally affected. Similarly, when another E190, VH-UYB, was under heavy maintenance at a different facility at around the same time, the torque tube driving the left wing flap actuator number 2 was incorrectly assembled in that the locking bolt had not passed through the hole in the actuator’s splined shaft. The torque tube disengaged 35 flights after the aircraft re-entered service and the flap system failed.

Non-detection of the error

The 2 AMEs who fitted the torque tube in VH-UZD did not identify that the torque tube had been incorrectly fitted. Further, the LAME checking this work and the second LAME carrying out the independent inspection of this work did not identify that it had been incorrectly assembled. The similar error affecting VH-UYB also apparently remained undetected by those carrying out and certifying for the work.

As far as could be established, there were no physical or environmental factors that may have influenced the incorrect assembly of the torque tube. The work on VH-UZD was carried out in a new facility with good lighting, and access to the work area was good and could be carried out with the relevant components at eye level.

Ultimately, it is likely that not knowing the subtle difference in appearance of an incorrectly assembled slat torque tube (that is, as little as about 6.35 mm more of the actuator spline visible) contributed to the error not being detected by the 2 AMEs and the 2 LAMEs involved. Further, the remaining torque tubes in the slat drive system were correctly assembled, however their subtly different appearance did not trigger recognition that the original torque tube had been incorrectly assembled.