Category Archives: EASA

EASA declares Boeing 737 MAX safe to return to service in Europe

The European Union Aviation Safety Agency (EASA) gave its seal of approval for the return to service of a modified version of the Boeing 737 MAX, mandating a package of software upgrades, electrical wiring rework, maintenance checks, operations manual updates and crew training which will allow the plane to fly safely in European skies after almost two years on the ground.

“We have reached a significant milestone on a long road,” said EASA Executive Director Patrick Ky. “Following extensive analysis by EASA, we have determined that the 737 MAX can safely return to service. This assessment was carried out in full independence of Boeing or the Federal Aviation Administration and without any economic or political pressure – we asked difficult questions until we got answers and pushed for solutions which satisfied our exacting safety requirements.  We carried out our own flight tests and simulator sessions and did not rely on others to do this for us.

“Let me be quite clear that this journey does not end here,” he added. “We have every confidence that the aircraft is safe, which is the precondition for giving our approval. But we will continue to monitor 737 MAX operations closely as the aircraft resumes service. In parallel, and at our insistence, Boeing has also committed to work to enhance the aircraft still further in the medium term, in order to reach an even higher level of safety.”

The Boeing 737 MAX was grounded worldwide in March 2019 following the second of two accidents within just six months, which together claimed 346 lives. The root cause of these tragic accidents was traced to software known as the MCAS (Maneuvering Characteristics Augmentation System), intended to make the plane easier to handle. However, the MCAS, guided by only one Angle of Attack (AoA) sensor, kicked in repeatedly if that sensor malfunctioned, pushing the nose of the aircraft downward multiple times. In both accidents, pilots finally lost control of their plane, resulting in a crash with total loss of aircraft.

EASA’s conditions for Return to Service now met

In the days after the grounding, EASA set four conditions for the return to service of the aircraft:

  • The two accidents (JT610 and ET302) are deemed sufficiently understood
  • Design changes proposed by Boeing to address the issues highlighted by the accidents are EASA approved and their embodiment is mandated
  • An  independent extended design review has been completed by EASA 
  • Boeing 737 MAX flight crews have been adequately trained

“These four conditions have now all been met, allowing us to go ahead with the return to service,” Ky said.

To enhance transparency, a closing report released by the Agency explains its approach and the reasoning for its decisions.

While the investigations assessed that the behaviour of the MCAS and related alerting systems were the clear main cause of the two crashes, EASA rapidly realised that a far wider review of the 737 MAX was needed. EASA therefore extended its analysis to the entire flight control system. With a particular focus on the human factors – the actual experience for a pilot of flying the plane.

This extended review, conducted in close cooperation with FAA as primary certification authority, and with Boeing as manufacturer, continued to evolve over the course of the 20-month exercise. Its findings led to the definition of the broad package of actions specified in the Airworthiness Directive.

“The mandated actions need to be seen as a complete package which together ensure the aircraft’s safety,” Ky said. “This is not just about changes to the design of the aircraft: every individual 737 MAX pilot needs to undergo a once-off special training, including simulator training, to ensure that they are fully familiar with the redesigned 737 MAX and trained to handle specific scenarios which may arise in flight. This will be reinforced by recurrent training to ensure the knowledge is kept fresh.”

EASA has also agreed with Boeing that the manufacturer will work to even further increase the resilience of the aircraft systems to AoA sensor failures so as to further enhance the safety of the aircraft. Boeing will also conduct a complementary Human Factor assessment of its crew alerting system within the next 12 months, with the aim of identifying the need for longer term improvements.

Resumption of flights in Europe

The Airworthiness Directive, which details the aircraft and operational suitability changes, including crew training requirements, must be carried out before each individual plane returns to service, gives the green light from the EASA side for a return to service of the aircraft.

However, scheduling of these mandated actions is a matter for the aircraft operators, under the oversight of Member States’ national aviation authorities, meaning that the actual return to service may take some time. COVID-19 may also have an influence on the pace of return to commercial operations.

In conjunction with the Airworthiness Directive, EASA also issued a Safety Directive (SD) requiring non-European airlines which are holders of EASA third country operator (TCO) authorisation to implement equivalent requirements, including aircrew training. This will allow for the return to service of the 737 MAX when the aircraft concerned are operated under an EASA TCO authorisation into, within or out of the territory of the EASA Member States.

Additional information

In summary, the EASA Airworthiness Directive mandates the following main actions:

  • Software updates for the flight control computer, including the MCAS
  • Software updates to display an alert in case of disagreement between the two AoA sensors
  • Physical separation of wires routed from the cockpit to the stabiliser trim motor
  • Updates to flight manuals: operational limitations and improved procedures to equip pilots to understand and manage all relevant failure scenarios
  • Mandatory training for all 737 MAX pilots before they fly the plane again, and updates of the initial and recurrent training of pilots on the MAX
  • Tests of systems including the AoA sensor system
  • An operational readiness flight, without passengers, before commercial usage of each aircraft to ensure that all design changes have been correctly implemented and the aircraft successfully and safely brought out of its long period of storage.

For details, see the text of the Airworthiness Directive (AD).

EASA, and regulators in Canada and Brazil, worked closely with the FAA and Boeing throughout the last 20 months to return the plane safely to operations. These three authorities have already approved the aircraft for the return to service.

The EASA AD requires the same physical changes to the aircraft as the FAA, meaning that there will be no software or technical differences between the aircraft operated by the United States operators and by the EASA member states operators (the 27 European Union members plus Iceland, Liechtenstein, Norway and Switzerland). Following the exit of the United Kingdom from the European Union, the UK Civil Aviation Authority is now responsible for clearing the aircraft to operate to/from and within the U.K as well as for U.K. operators.

However, EASA’s requirements differ from the FAA in two main respects. EASA explicitly allows flight crews to intervene to stop a stick shaker from continuing to vibrate once it has been erroneously activated by the system, to prevent this distracting the crew. EASA also, for the time being, mandates that certain types of high-precision landings cannot be performed. The latter is expected to be a short-term restriction. The mandated training for pilots is broadly the same for both authorities.

Some EASA member states issued their own decision prohibiting the operation of the 737 MAX last year for their sovereign airspace. These bans will need to be lifted before the aircraft can fly again in the airspace of these countries.  EASA is working closely with the relevant national authorities to achieve this.

During the 28-day public consultation, comments on the AD were received from 38 commenters. These have all been responded to in the Comment Response Document published with the AD. For the SD, there were 6 commenters. Responses to these comments can be found on the Comment Response Document published with the SD.  In summary, the comments resulted in some minor changes to the texts, such as corrections to typing errors, updated document references and clarifications required by the commenters. There were no substantive changes made to the actions that need to be implemented.

EASA lays out tougher conditions for the return of Boeing 737 MAX in Europe

The European Union Aviation Safety Agency (EASA) published a Proposed Airworthiness Directive (PAD) concerning the Boeing 737 MAX for public consultation, signalling its intention to approve the aircraft to return to Europe’s skies within a matter of weeks.

The Boeing 737 MAX was grounded by EASA on March 12, 2019, following two accidents with total loss of aircraft in which 346 people died. Intense work involving the dedicated attention from around 20 EASA experts over a period of around 20 months has now given EASA the confidence to declare the aircraft will be safe to fly again. The Federal Aviation Administration of the United States (FAA), State of Design for Boeing aircraft, published its final approval of the modified 737 MAX in the Federal Register on November 20, 2020.

“EASA made clear from the outset that we would conduct our own objective and independent assessment of the 737 MAX, working closely with the FAA and Boeing, to make sure that there can be no repeat of these tragic accidents, which touched the lives of so many people,” said EASA Executive Director Patrick Ky.

“I am confident that we have left no stone unturned in our assessment of the aircraft with its changed design approach,” he added. “Each time when it may have appeared that problems were resolved, we dug deeper and asked even more questions. The result was a thorough and comprehensive review of how this plane flies and what it is like for a pilot to fly the MAX, giving us the assurance that it is now safe to fly.”

Investigations into the two accidents showed that a primary cause in each was a software function programme known as the Manoeuvring Characteristics Augmentation System (MCAS), which was intended to make the aircraft easier to handle. However, the MCAS, guided by only one Angle of Attack (AoA) sensor, kicked in repeatedly if that sensor malfunctioned, pushing the nose of the aircraft downward multiple times and leading finally in both accidents to a complete loss of control of the aircraft.

“EASA’s review of the 737 MAX began with the MCAS but went far beyond,” Ky said. “We took a decision early on to review the entire flight control system and gradually broadened our assessment to include all aspects of design which could influence how the flight controls operated. This led, for example, to a deeper study of the wiring installation, which resulted in a change that is now also mandated in the Proposed Airworthiness Directive. We also pushed the aircraft to its limits during flight tests, assessed the behaviour of the aircraft in failure scenarios, and could confirm that the aircraft is stable and has no tendency to pitch-up even without the MCAS.”

Human factor analysis was another focus area – to ensure that the pilots were provided with the right alerts in the cockpit if a problem arose, along with the procedures and training needed to know how to respond. A fundamental problem of the original MCAS is that many pilots did not even know it was there. In the accident version of the aircraft, there was no caution light to make a pilot aware that the AoA sensor was faulty, making it almost impossible to determine the root cause of the problem.

That is why EASA now proposes that the changes to the aircraft design which will be required by the final Airworthiness Directive will be accompanied by a mandatory training program for pilots, including flight simulator training, to ensure that the pilots are familiar with all aspects of the flight control system of the 737 MAX and will react appropriately to typical failure scenarios. 

The EASA Proposed Airworthiness Directive is now open for a 28-day consultation period. Once that ends, EASA will take time to review the comments made, before publishing its final Airworthiness Directive. That final publication is expected from mid-January 2021 and will constitute the formal ungrounding decision of the plane for all 737 MAX aircraft operated by operators from EASA Member States. After the return to service, EASA has committed to monitor the plane closely in-service, to allow for early detection of any problems that may arise.

In conjunction with the Proposed Airworthiness Directive, EASA also issued a Preliminary Safety Directive for 28-day consultation. This will require non-European airlines which are holders of EASA third country operator (TCO) authorisation to implement equivalent requirements, including aircrew training. This will allow for the return to service of the 737 MAX when the aircraft concerned are operated under an EASA TCO authorisation into, within or out of the territory of the EASA Member States.

Additional information
In summary, the EASA Proposed Airworthiness Directive mandates the following main actions: 

  • Software updates for the flight control computer, including the MCAS
  • Software updates to display an alert in case of disagreement between the two AoA sensors
  • Physical separation of wires routed from the cockpit to the stabiliser trim motor
  • Updates to flight manuals: operational limitations and improved procedures to equip pilots to understand and manage all relevant failure scenarios
  • Mandatory training for all 737 MAX pilots before they fly the plane again, and updates of the initial and recurrent training of pilots on the MAX
  • Tests of systems including the AoA sensor system
  • An operational readiness flight, without passengers, before commercial usage of each aircraft to ensure that all design changes have been correctly implemented and the aircraft successfully and safely brought out of its long period of storage. 

For details, see the text of the Proposed Airworthiness Directive.

EASA, and regulators in Canada and Brazil, worked closely with the FAA and Boeing throughout the last 20 months to return the plane safely to operations.

The EASA Proposed Airworthiness Directive requires the same changes to the aircraft as the FAA, meaning that there will be no software or technical differences between the aircraft operated by the United States operators and by the EASA member states operators (the 27 European Union members plus Iceland, Liechtenstein, Norway and Switzerland. The United Kingdom is until December 31, 2020 also treated as an EU member state.)

However, EASA’s requirements differ from the FAA in two main respects. EASA explicitly allows flight crews to intervene to stop a stick shaker from continuing to vibrate once it has been erroneously activated by the system, to prevent this distracting the crew. EASA also, for the time being, mandates that the aircraft’s autopilot should not be used for certain types of high-precision landings. The latter is expected to be a short-term restriction.

The mandated training for pilots is broadly the same for both authorities.

Before individual airlines can assign the plane to their flight schedules, they will need to complete all the software upgrades and maintenance actions described in the final Airworthiness Directive. They also need to train their 737 MAX pilots. As there are only a limited number of simulators, this may take some time to schedule. Some of this work can be started now, even in advance of the final Airworthiness Directive publication.

Some EASA member states issued their own decision prohibiting the operation of the 737 MAX last year for their sovereign airspace. These bans will need to be lifted before the aircraft can fly again in the airspace of these countries.  EASA is working closely with the relevant national authorities to achieve this.

EASA has also agreed with Boeing that the manufacturer will work to even further increase the resilience of the aircraft systems to AoA sensor failures so as to further enhance the safety of the aircraft. Boeing will also conduct a complementary Human Factor assessment of its crew alerting systems within the next 12 months, with the aim of potentially upgrading these to a more modern design approach.

EASA issues warnings to Airbus A321neo operators about excessive pitch attitude under certain conditions

EASA has issued this Airworthiness Directive concerning the new Airbus A321neo:

Manufacturer(s):

Airbus

Applicability:

Airbus A321-251N, A321-252N, A321-253N, A321-271N, A321-272N, A321-251NX, A321-252NX, A321-253NX, A321-271NX and A321-272NX aeroplanes, all manufacturer serial numbers.

Definitions:

For the purpose of this AD, the following definitions apply:

Affected ELAC: Elevator Aileron Computer (ELAC) unit having Part Number (P/N) 3945129100 with L102 software P/N 3945129114 (data-loadable); or ELAC unit having P/N 3945128220 (non-data-loadable).

The applicable AFM TR: Airbus Aircraft Flight Manual (AFM) Temporary Revision (TR) 766, TR 767, TR 768, TR 769, TR 770, TR 771 issue 2 and TR 772 issue 2, as applicable.

EASA AD No.: 2019-0171

Groups:
Group 1 aeroplanes are those that have affected ELAC installed.
Group 2 aeroplanes are those that do not have affected ELAC installed.

Reason:

Analysis of the behavior of the ELAC L102 installed on A321neo revealed that excessive pitch attitude can occur in certain conditions and during specific manoeuvres.

This condition, if not corrected, could result in reduced control of the aeroplane.

To address this potential unsafe condition, Airbus issued the applicable AFM TR to provide operational limitations.

For the reason described above, this AD requires amendment of the respective AFM, with AFM TR, as applicable.

This AD is considered to be an interim action and further AD action may follow.

Required Action(s) and Compliance Time(s):

Required as indicated, unless accomplished previously:

AFM Change:

  1. (1)  For Group 1 aeroplanes: Within 30 days after the effective date of this AD, amend the applicable AFM to incorporate the applicable AFM TR, inform the flight crews, and, thereafter, operate the aeroplane accordingly.
  2. (2)  For Group 2 aeroplanes: From the effective date of this AD, before next flight after modification of an aeroplane to install affected ELAC, amend the applicable AFM to incorporate the applicable AFM TR, inform the flight crews, and, thereafter, operate the aeroplane accordingly.
  3. (3)  For Group 1 and Group 2 aeroplanes: Amending the applicable AFM of an aeroplane to incorporate later AFM revisions, which include the same content as the applicable AFM TR, is acceptable to comply with the requirements of paragraph (1) or (2) of this AD, as applicable, for that aeroplane.

EASA suspends all Boeing 737 MAX operations in Europe, a total shutdown

Europe is now closed to all Boeing 737-8 MAX 8 and Boeing 737-9 MAX 9 operations. EASA has issued this statement:

Following the tragic accident of Ethiopian Airlines flight ET302 involving a Boeing 737 MAX 8, the European Union Aviation Safety Agency (EASA) is taking every step necessary to ensure the safety of passengers.

As a precautionary measure, EASA has published today (March 12) an Airworthiness Directive, effective as of 19:00 UTC, suspending all flight operations of all Boeing Model 737-8 MAX and 737-9 MAX airplanes in Europe. In addition EASA has published a Safety Directive, effective as of 19:00 UTC, suspending all commercial flights performed by third-country operators into, within or out of the EU of the above mentioned models.

The accident investigation is led by the Ethiopian Authorities with the support of the National Transportation Safety Board, as the aircraft was designed and built in the United States. EASA has offered their assistance in supporting the accident investigation.

EASA is continuously analysing the data as it becomes available. The accident investigation is currently ongoing, and it is too early to draw any conclusions as to the cause of the accident.