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Embraer 190 accident Nov 2018


On 2-October-2018 a Aruba registered Embraer 190, operated by Air Astana was inducted into a well reputable and large MRO in Alverca do Ribatejo, Portugal.

The work pack consisted of a C2 heavy maintenance check and several modifications.

On 9-Oct one of the mods initiated, was a modification to the aileron cables as per Embraer SB 190-57-0038R2, a structural modification that removed cable pulleys to replace them with a non friction cable guidance.

For that, the aileron cable had to be disconnected and reconnected after replacement of the cable guides.

In addition, another modification was carried out to replace stainless steel cables with carbon steel cables (SB 190-27-0037R1).

On 26-Oct, during tests after replacing cables and guides, after operational testing, a EICAS message [FLT CTR NO DISPATCH] appeared on the screen in the flight deck.

Other typical post maintenance testing was carried out subsequently and the initial delivery date of 24-Oct was renegotiated to 31-Oct. The "NO DISPATCH" message remained.

At that time, internal and external pressure on the MRO was building and after an extensive period of time troubleshooting, in which the MRO, operator and OEM (Embraer) participated, the aircraft was released and offered to the acceptance crew.

Spoiler alert! The aileron cables had been cross connected, causing the ailerons to operate reversed.

The aircraft departed for a ferry flight and obviously, shortly after take off, the aircraft suffered severe controllability problems. During flight, the aircraft attained extreme attitude and altitude excursions and was subject to structural overloads.

The crew eventually managed after an eventful flight and a go around to land the aircraft at the departure base. The crew were mentally and physically exhausted and one crew member got injured during the many uncontrolled deviations of the aircraft and had to be taken to hospital. Ultimately the crew survived. The aircraft was (after thorough assessment) deemed damaged beyond economical repair due to structural damage caused by aerodynamic overload

Full official report attached.

The report focusses obviously heavily on the breakdown in processes and procedure within the MRO and the unjustified release of the aircraft containing a potentially fatal flaw it its flight control system.

Recently it became public that the MRO publicly pushes back against the focus on them (without discounting their mistakes) and blaming the commission for an unbalanced view.


We tend to agree and here's why.


Management pressure on schedules are very common in day to day MRO life. Every experienced foreman and manager knows that it is imperative to keep this pressure away from mechanics and allow them to do their work without distraction. They know already the aircraft runs late. But there's more.


In the 16 days after the [FLT CTR NO DISPATCH] message appeared, the MRO and its staff were troubleshooting a problem without seeing the obvious mistake made (reversal of the aileron cables).

They invited participation of the operator and MRO to assist in this troubleshooting and they also failed to detect the simple and obvious flaw.

The report stated breakdown in procedures and failure to maintain Safety Management System (SMS) procedures.

We think this is a symptom rather than a cause.

The 16 days troubleshooting took longer than the time it took to modify the aircraft which reflects the level of desperation of the organisation to find the problem

In that time the people directly involved failed to detect the simple and fundamental mistake which indicates that they were all looking in the wrong direction, not being able to step back and systematically evaluate all the steps taken or were "blind" seeing the problem.

If a large group of people are communicating intensely and are still making fundamental errors in thought without mitigation, this is called "groupthink" in anthropology.

It happens everywhere in all sorts of organisations. This is what most likely happened in this case, leading up to a near catastrophical accident.


Interestingly, I have seen this happen a number of times in my time in MRO's on several different occasions.

It can be dangerous and the remedy would be to identify the phenomenon which shows itself by repetitive thought processes by all group members without achieving progress.

Once identified; the mitigation would be to (re)define the objective and deficit gap and to isolate people from each other and ask individual members (or small sub groups) to produce a proposal for mitigation based on knowledge and also on intuition..

All the proposals need to be taken seriously without prejudice and carried out in order to produce the desired result.

Please leave comments!


Incident report Embraer 190 2018
.pdf
Download PDF • 6.26MB



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