On 11 November, an Air Astana Embraer ERJ-190LR (P4-KCJ) from Alverca Airport, Portugal and performing a first flight – after six weeks of maintenance at Indústria Aeronáutica de Portugal S.A. (OGMA) – towards Minsk Airport as KC1388 declared a “Mayday” suffering from control issues. The pilots briefly considered a ditching but were able to regain control of the aircraft. The pilots then decided to head to Beja Airport for a safe landing on runway 19R. During the emergency situation, two F-16 fighter jets of the Portuguese Air Force scrambled to assist the aircraft.

The Embraer involved spent the last 6 weeks on the ground in OGMA, Alverca, for maintenance work. OGMA, Indústria Aeronáutica de Portugal S.A. is a Portuguese aerospace company providing maintenance services and manufacture of aerostructures.

The aircraft took off at 13:31 hours (UTC) with six people on board. Five minutes into the flight, the aircraft began squawking 7600 (Radio failure – lost communications). At 14:01, emergency squawk 7700 was used. At 15:01 and after three attempts, the aircraft landed at Beja Airport.

Air Astana confirmed the technical issues hence the pilots diverted to Beja Airport, three pilots and three technicians but no passengers were on board the aircraft. One crew member sustained a leg injury and was taken to hospital for a checkup.

A forum topic has been created to discuss this emergency, live air traffic control footage has been added in the forum topic. An interesting read!

Speed, altitude and track show the loss of control of the aircraft

BREAKING: Air Astana #KC1388 out of Lisbon is squawking 7700 General Emergency. Just told scrambled Portuguese Air Force pilot on frequency he is planning to ditch in the sea – “uncontrollable aircraft”. Listen live via @liveatc : https://t.co/BQhFiAjPIdhttps://t.co/sBCTVAgcii pic.twitter.com/G8C89E4GjB — Airport Webcams (@AirportWebcams) November 11, 2018

Whoever is at the controls of #KC1388 right now is doing some incredible and completely insane shit. Hope they know what they’re doing and can land safely pic.twitter.com/LeocdHcB4z — Walker Eats It (@MEbelMath) November 11, 2018

⚠️🚨✈️ #KZR1388 Podemos informar que o avião aterrou na pista 19R da Base Aérea de #Beja ✈️ ⚠️🚨 #CaseClosed — VOST Portugal 🇵🇹 (@VOSTPT) November 11, 2018

11 ноября самолёт Embraer 190 выполнял перегоночный рейс KC1388 из авиационно-технического центра Португалии. Во время полёта возникли технические неполадки, из-за чего экипаж совершил посадку в аэропорту г. Бежа. Пассажиров на борту не было. — Air Astana (@airastana) November 11, 2018

VIDEO: #KC1388 escorted to Beja Airport after the aircraft became uncontrollable due to instrument loss on departure from Lisbon Pilots managed to gain some control and two F-16 Jets from the Portuguese Air Force guided the aircraft to landpic.twitter.com/79wOJXvfra — Flight Alerts (@FlightAlerts_) November 11, 2018

Exclusive footage taken on board one of the F-16 fighter jets that scrambled to assist the aircraft

Preliminary report of the GPIAAF (Gabinete de Prevenção e Investigação de Acidentes com Aeronaves e Acidentes Ferroviários) – Portuguese Aviation Authorities (Lisbon, 13 November 2018)

An Embraer 190-100LR, with Aruba registration P4-KCJ, operated by Air Astana, took-off at 13:31, 11 NOV 2018, from Alverca do Ribatejo airbase, where it was under a scheduled maintenance performed at OGMA, Indústria Aeronáutica de Portugal, S.A. facilities.

The flight KC1388 had as final destination the operator base at Almaty, Kazakhstan, with a refueling stop-over at Minsk, Belarus.

On board there were three crew members (a captain and two co-pilots), and three technicians from the operator.

Immediately after take-off, with adverse meteorological conditions, the crew felt that the aircraft was not responding adequately to the commands, developing oscillatory wing movements.

The crew, using all the aircraft control resources for its 3 axis, immediately tried to counter the movements, however without understanding the cause for the flight instability and without being able to engage the autopilot.

Realising that they were without effective control of the aircraft, only being able – with considerable effort – to minimize the oscillatory movements, with high structural loads involved during some recovery manoeuvres and using crossed commands.

The crew immediately declared emergency while trying to diagnose the cause for the abnormal roll of the aircraft, continuing to struggle to gain its control, having no malfunction indication from the aircraft systems, just the continuous alerts for abnormal

flight attitudes.

The situation did not improve, and the performed trajectories caused the aircraft and the persons on board to sustain intense G-forces, and causing the aircraft complete loss of control for some moments at multiple instances.

Considering the situation criticality, the crew requested several times for headings in order to be able to reach the sea for ditching, not being able, however, to keep the intended headings.

The crew then started a team work basis, discussing options with the third crewmember (co-pilot in the jump-seat) and trying to communicate with the technicians on board, to explore hypothesis and define an action plan.

Despite no warnings for system failures, the crew decided to activate the flight controls direct mode (elevators, rudder and spoilers), where the flight control module (FCM) is removed from the flight surfaces command chain, which are then controlled in a direct relationship with the pilots’ inputs on the yoke.

The situation improved considerably, however, without restoring normal operation and keeping the difficulties to control the aircraft roll-axis.

The crew realised that the ailerons were behaving erratically and therefore any command for the aircraft roll was kept to its minimum.

Having gained some control of the situation, the crew flew East, searching for better weather conditions and started to follow the flight plan defined by the air traffic control for an emergency landing in a suitable airport, with good weather and physical conditions to deal with the sustaining aircraft control difficulties.

At this moment, when the pilots were able to keep altitude and heading, and had sufficient visual references, the aircraft was joined by a pair of F-16 fighters from the Portuguese Air Force, which assisted in guiding to Beja airport, which had been selected in the meantime as the best emergency landing option.

After two non-stabilised approaches, the aircraft managed to land safely on runway 19L at the third approach. The intended runway was 19R, but due to drift, they finally managed to land on the left runway.

All on board were physically and emotionally shaken, one of the passengers sustaining a leg injury.

Still pending confirmation from the undertaking of additional testing, the evidence that was possible to collect at the time of drafting this Note suggests the existence of failures in the aircraft roll controls configuration, consistent with possible disturbance during maintenance actions.

NOTE: The times mentioned are all UTC.

About the investigation

GPIAAF was notified shortly after the beginning of the occurrence and an investigation team travelled to the emergency landing airport for evidence gathering.

GPIAAF started a safety investigation process to identify the serious incident causes in accordance with Portuguese Decree-Law no. 318/99, EU Regulation no. 996/2010 and Annex 13 to the Convention on International Civil Aviation.

Amongst other issues, the safety investigation will look into the functioning of the aircraft, the crew procedures, the maintenance performed to the aircraft, the human and organizational factors involved.

The safety investigation carried out by GPIAAF has the sole purpose of identifying causal and contributing factors involved in accidents or incidents, in order as to recommend, if relevant, any action that it considers necessary to be taken to enhance aviation safety. The investigation is independent and separate from any judicial or administrative proceedings to apportion blame or liability.

Within the scope defined by the international legislation, the investigation may have the participation of representatives from EASA, from the national civil aviation authorities of the Member States concerned, and from the State of Registry, the State of the Operator, the State of Design and the State of Manufacture.

After concluding the investigation and consultation to the relevant parties, GPIAAF will publish the final report. According to national and European legislation, if the final report cannot be made public within 12 months, an interim statement will be released at least at each anniversary of the accident, detailing the progress of the investigation and any safety issues raised. Any urgent safety issues detected in an investigation are immediately

transmitted to relevant parties to allow them to act accordingly.