Russian SU95 Accidently Drops Its Gear Causing A Loss Of Separation

An Azimuth Airlines Sukhoi Superjet 100-95 found itself at a loss of separation with another aircraft over the skies of Rostov-On-Don last month. The loss was due to the pilot accidentally hitting the wrong switch and deploying the landing gear, causing the plane to climb. Let’s find out more.

Azimuth Airlines Sukhoi Superjet
The SJ100-95 triggered the Short Term Collision Warning at Air Traffic Control due to the sudden climb. Photo: Getty Images

Wrong switch

According to the Aviation Herald, the skies over Rostov-On-Don saw a chaotic few minutes on October 21st. The incident was caused by an Azimuth Airlines Superjet 100-95, flying a domestic Russian service from Sochi to Bryansk. Flight A4-543 had taken off an hour ago before the crew started facing lost signal prompts from the satellite navigation system.

The captain attempted to remove the prompts from the flight management system and other displays to continue assessing the situation. However, while trying to cancel the message, he accidentally pushed the alternate gear extension button. This happened while the aircraft was cruising at 270 knots, above the 255-knot limit to deploy the landing gear.

The aircraft was forced to divert after the errors appeared an hour into the flight. Map:

The sudden deployment of the gear occurred while the aircraft was still on autopilot, causing the system to suddenly increase the plane’s altitude by roughly 450 feet, sending the SU95 to 34,400 feet before descending again.

Alarms off

As the SU95 changed altitude without prior clearance with Air Traffic Control (ATC), alarms went off in the tower. The alarm was triggered by the presence of another aircraft coming in the opposite direction at 35,000 feet, causing the Short Term Collision Warning to activate. Luckily, the SU95 had rapidly decreased altitude and was not at risk of a collision.

Soon after the incident, the crew requested permission to descend to 29,000 feet and divert to Rostov Airport. This was quickly approved, and the aircraft landed safely in Rostov 35 minutes after the issues began.

Azimuth Airlines SJ100
Azimuth Airlines operates an all-Superjet fleet. Photo: Anna Zvereva via Flickr

After 18 hours on the ground, the SJ100-95 was back in active service and has not seen subsequent issues with its navigation. The aircraft involved in the incident was registered RA-89120, a three-year-old Sukhoi Superjet 100.

The plane was delivered in October 2019, according to, which means the incident occurred just a year into the plane’s use in active service. However, the issues seem to have been quickly resolved, and Azimuth has been involved in some more interesting incidents since.


Azimuth Airlines is a Russian airline founded in February 2017 and based in Rostov-On-Don. The airline was created to fill demand in Rostov following the merger of Donavia with the Aeroflot group and the upcoming FIFA World Cup in 2018. However, the carrier has grown quickly over four years.

Now, Azimuth operates an all-Superjet 100 fleet of 15 aircraft with an average age of only 3.6 years. However, this won’t be for much longer. In July, the airline ordered six Airbus A220s to expand its reach, seating 148 passengers in economy, and becoming the first Russian carrier to fly the type.