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UK CAA clears Boeing 737 MAX for return to service
28 January 2021

UK CAA clears Boeing 737 MAX for return to service

The UK Civil Aviation Authority (CAA) has announced on January 27 and with immediate effect that it will allow UK airlines to operate passenger flights with the Boeing 737 MAX aircraft, subject to close oversight. The ban on the aircraft operating in UK airspace will also be removed.  

The decision follows the approval of design modifications to the aircraft itself, how it is flown, and to pilot training.  This has included modification to the aircraft’s Manoeuvring Characteristics Augmentation System (MCAS) and other key safety changes aimed at preventing further accidents.

The CAA is in close contact with TUI, currently the only UK operator of the aircraft, as it returns its aircraft to service.

The removal of the airspace ban will allow foreign operators to fly the Boeing 737 MAX in UK airspace. All airlines, however, will need to go through the necessary steps to return the aircraft to service, including pilot training, so this may result in flights of the type into the UK not being seen immediately.

The main modifications to the aircraft that allow a safe return to service are:

  • Flight Control Computer (FCC) software changes, so that both of the aircraft’s Angle of Attack (AoA) sensor inputs are used by the aircraft systems (rather than previously one)
  • safeguards against MCAS activating unnecessarily, due to a failed or erroneous AoA sensor
  • removal of the MCAS repeat command
  • revised limits on the MCAS command authority
  • revisions to flight crew procedures and training requirements
  • implementation of an AoA ‘disagree’ alert indication that would appear on the pilots’ primary flight displays
  • cross FCC trim monitoring, to detect and shutdown erroneous pitch trim commands

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

The European Union Aviation Safety Agency (EASA) allows return to service of a modified version of the Boeing 737 MAX, mandating a package of software upgrades, electrical working rework, maintenance checks, operations manual updates and crew training.

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.

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
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. 

Distraction factor in ATR 72’s attempted takeoff from runway edge, Cologne

EASA publishes European Plan for Aviation Safety 2021-2025

The European Union Aviation Safety Agency (EASA) published the 10th edition of the European Plan for Aviation Safety (EPAS) covering 2021 – 2025.

EPAS sets out the strategic priorities and enablers, and the main risks affecting the European aviation system, while also defining actions to mitigate the risks.

EPAS is a key component of the Commission’s European Aviation Safety Programme (EASP), supporting the goals and objectives of the ICAO Global Aviation Safety Plan (GASP) for all 55 in the ICAO EUR Region. 

More information:
European Plan for Aviation Safety 2021-2025

Misinterpretation of ATC communication factor in August 2019 runway incursion at Toronto

The Transportation Safety Board of Canada (TSB) released its investigation report into the August 2019 runway incursion between two aircraft at the Toronto/Lester B. Pearson International Airport, Canada.

On 9 August 2019 at 12:40 local time, an Air Canada Boeing 777-300 landed on runway 33L. Three minutes later, an Air Georgian CRJ-200 was instructed to line up on parallel runway 33R. In accordance with air traffic control (ATC) instructions, the Boeing 777 was crossing runway 33R. Simultaneously, the flight crew of the CRJ-200 began its take-off roll on the same runway without a take-off clearance from ATC. When the CRJ-200 flight crew saw the Boeing 777 over the crest of the runway, they rejected the takeoff and exited via a taxiway.

The investigation found that while completing the pre-departure checks, the flight crew of the CRJ-

200 was informed of a change in departure instructions. The first officer received and read back the line-up instruction with the departure amendment, but misinterpreted that ATC communication as a clearance for takeoff.

It was determined that the number of pre-departure tasks the flight crew was required to complete within a short amount of time increased their workload, and that the workload was further increased by the additional tasks brought by the change in instructions. Thus, it was found that the increased workload, the expectation to receive a take-off clearance without delay, and the misinterpretation of the line-up instructions led the CRJ-200 flight crew to initiate take-off roll without a take-off clearance. Also, because of the grade profile of runway 33R, the fuselage of the Boeing 777 would not have been visible to the CRJ-200 flight crew at the start of the take-off roll, therefore they had no visual indication that it was unsafe to begin the takeoff.

Following the occurrence, NAV CANADA issued a directive reminding air traffic controllers to cancel the take-off clearance or issue an instruction to abort takeoff when runway incursion monitoring and conflict alert system stage 2 alerts are activated by a departing aircraft.

Air Georgian Limited conducted an internal safety investigation as per the company’s safety management system. It amended its standard operating procedures to mandate an ATC query if one of the two crew members was unaware of the content of an ATC clearance or instruction.

Sriwijaya Air Boeing 737-500 crashed after takeoff from Jakarta

ASN Accident Statistics Highlight Need for More Work on Runway Excursions, Conflict Zones

The international airline industry in 2020 suffered eight fatal accidents resulting in 314 fatalities, both of which are below the industry’s five-year average, according to statistics released today by the Aviation Safety Network (ASN). Included in the 2020 totals are two events in which airliners were inadvertently shot down, killing 182 passengers and crew.

Eight fatal accidents are the fewest on record for a full year. The safest year in aviation history was 2017 with 10 fatal accidents and 44 lives lost.

The global COVID-19 pandemic had a severe impact on the aviation industry in 2020, causing a significant drop in the number of flights operated. Industry studies suggest that worldwide air traffic in 2020 was about half of that in 2019. Just over 19 million flights were operated last year, which is about the same number as were flown in 1999, when ASN registered 43 fatal accidents resulting in 689 fatalities.

Major improvements have been made in aviation safety over the past 20 years, but significant challenges remain, and two of those were underscored in 2020: approach and landing accidents and commercial flights over conflict zones.

Runway excursion accidents in Turkey and India resulted in 23 fatalities.

“These two runway excursion accidents highlight the fact that much still needs to be done to prevent overruns and to make sure runway environments follow International Civil Aviation Organization (ICAO) recommendations,” said ASN CEO Harro Ranter.

“International aviation provides critical economic and social connectivity, but the global nature of aviation can put it at risk when flights overfly conflict zones,” said Foundation President and CEO Dr. Hassan Shahidi. “All countries must adhere to established ICAO guidance on aircraft flying through conflict zones. It is the responsibility of the state to provide timely risk information to airlines during military conflict and to close its airspace if necessary.”

The ASN statistics are based on all worldwide fatal commercial aircraft accidents (passenger and cargo flights) involving civil aircraft of which the basic model has been certified for carrying 14 or more passengers.

The Aviation Safety Network is an independent organisation located in the Netherlands. Founded in 1996, its goal is to provide everyone with a professional interest in aviation with up-to-date, complete and reliable authoritative information on airliner accidents and safety issues. ASN is an exclusive service of Flight Safety Foundation. The figures have been compiled using the airliner accident database of the Aviation Safety Network, the internet leader in aviation safety information. The Aviation Safety Network uses information from authoritative and official sources.

More information:

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Harro Ranter
the Aviation Safety Network
e-mail: hr@aviation-safety.net
twitter: @AviationSafety

FAA extends conflict zone Notam on Pakistan airspace by a year

The U.S. Federal Aviation Administration extended the Conflict Zone Notam on Pakistani airspace by a year, to 1 January 2022.
Although there were no extremist/militant attacks against civil aviation in the territory and airspace of Pakistan in 2020, the FAA states, civil aviation remains an attractive target for extremist/militant groups due to the impact and visibility of such attacks.

Learjet 31 suffers runway excursion after landing at Diamantina Airport, Brazil

Avianca A319 struck pyrotechnic balloon on landing at Bogotá Airport, Colombia