Two separate incidents involving Alliance Airlines Embraer E190 aircraft resulted in landings with incorrect flap settings due to procedural oversights, an Australian Transport Safety Bureau investigation found.

The incidents, which occurred in February and March, revealed that flight crews in both cases had forgotten they had briefed for full flap landings approximately 25 minutes earlier during their approach preparations, and instead incorrectly configured their aircraft for flap 5 landings.

ATSB Director Transport Safety Stuart Macleod noted that while both landings were completed safely, the configuration errors could have had more serious implications.

“Landing in a different configuration to what was planned can result in reduced margins for landing speeds, and therefore reduced margins for safe operation,” Macleod said.

In both occurrences, flight crews had entered the appropriate landing speeds for full flap into the flight management system prior to descent. However, when configuring the aircraft for landing, the crews reverted to using flap 5, which is the more commonly used setting, resulting in the aircraft flying with approach speeds that were 8 knots slower than required for the actual configuration.

No Crosscheck Procedure

The investigation identified that the airline had no procedure for flight crews to crosscheck the briefed flap setting with the actual configuration selected during the before landing checklist. This was identified as a key contributing factor to both incidents.

The first incident occurred on February 4, involving an E190 aircraft registered as VH-A2T, which was operating flight QQ3120 from Adelaide to Olympic Dam, South Australia. The captain had elected to use full flap due to turbulent and windy conditions, but later selected flap 5 during the approach.

The second incident occurred on March 8, when an E190 aircraft registered as VH-A2V operating flight QQ4801 from Alice Springs to The Granites, Northern Territory, experienced a similar configuration error. In this case, the crew had chosen full flap to avoid a recently repaired runway area.

Human Factors

The ATSB investigation highlighted the human factors aspects of these incidents, particularly related to memory limitations over time. According to the report, “Both sets of crewmembers rarely, if ever, operated Load 25 aircraft, and in both incidents, the crews reverted to setting the flaps to flap 5, an action they had performed many times previously (procedural memory).”

Unlike the company’s aircraft equipped with more recent Load 27 software, which provides a message when there’s a discrepancy between the flap position entered in the flight management system and the actual flap lever position, the Load 25 aircraft involved in these incidents had no such warning system.

In response to the findings, Alliance has implemented several safety actions. The company amended its Operations Policy and Procedures Manual to mandate that the before landing checklist includes confirmation that the actual landing flap setting aligns with the planned flap configuration.

Additionally, the operator now requires that for E190 operations, the multifunction control and display unit page displaying required landing flap must be selected on the pilot flying side before the approach commences.

The ATSB report emphasized that these incidents demonstrate “the importance in multi-crew operations of the role of the pilot monitoring in identifying if, and intervening when, the other flight crew member deviates from the briefed plan.”

The investigation also referenced the United Kingdom Civil Aviation Authority’s guidance on pilot monitoring skills, which suggests that during briefings for less common configurations, crews should include “monitor me” type comments to encourage intervention, such as “remind me we are doing a full flap landing.”

Alliance also conducted a flight data review of unstable approaches over the previous six months to identify and address any similar occurrences.