French investigators have determined that a Boeing 737-800 experienced two successive unreliable air data incidents, after an overnight technical check failed to uncover a latent flaw in its angle-of-attack sensor. The Transavia aircraft (F-GZHO) had been ferried from Norwich to Paris Orly on 7 February 2018, after undergoing maintenance, but its crew had to deal with airspeed, altitude and angle-of-attack "disagree" alerts during the flight. Investigation authority BEA says the aircraft underwent an overnight check at Orly, but a technician did not “strictly comply” with troubleshooting procedures in a fault isolation manual. As a result he did not test the stall management yaw damper computer to see whether it had recorded a failure – a test required after an angle-of-attack disagree alert. The aircraft was cleared to operate a service to Marrakech the following day, 8 February, but its pilots – one of whom was under instruction for captaincy – also experienced similar problems to those of the inbound crew. They ultimately decided to return to Orly. BEA says the maintenance team which inspected the aircraft noticed that the right-hand angle-of-attack sensor was “abnormally resistant” to being turned, and emitted “unusual clicking noises”. Tests on the yaw damper computer revealed error messages about a sensor anomaly, “requiring its replacement”, the inquiry adds. Examination of the faulty sensor by KLM Engineering and Maintenance in Amsterdam found damage to several internal components. The sensor has two resolvers, which transmit their data to aircraft systems, and one of these resolvers was blocked in rotation. Inspection of the resolver revealed a viscous and tacky substance preventing movement of parts. BEA says it could not determine whether the substance was present when the resolver or sensor were manufactured in 2014, or whether it was the result of later exposure. The aircraft was delivered new to Transavia in February 2015 and the sensor had not undergone disassembly since. But analysis of the aircraft’s flight data since its delivery revealed a gradually evolving dysfunction of the right-hand angle-of-attack sensor over the aircraft’s three years in service. The values from this sensor changed in “increasingly longer steps”, says BEA, compared with those from the sensor installed on the left-hand side. BEA says it could not establish why the flaw, present during the aircraft’s entire service life, led to the generation of alerts after the aircraft had spent time undergoing maintenance in Norwich. It points out, however, that one of the maintenance operations required the two angle-of-attack sensors to be manually rotated by 30°. No anomaly had been noticed, says the inquiry, but the handling might have “exacerbated the dysfunction” before the ferry flight to Paris. BEA adds that use of the fault isolation manual during the subsequent technical inspection at Orly would have ensured a “more complete” check. “The failure would have probably been detected and the sensor replaced,” it states.

Source: Cirium

China’s three largest carriers grew their domestic networks in October, tapping into second- and third-tier cities to launch new routes, as they recorded yet another month of domestic traffic recovery. The "Big Three" — Air China, China Eastern Airlines and China Southern Airlines — each launched more than 10 new domestic routes during the month. Among them, China Southern, which returned to profitability in its third-quarter earnings, rolled out the most number of new destinations, launching 18 routes. Air China announced 17 new routes, while China Eastern launched 12 routes. Some of the newly-launched routes were between smaller Chinese cities, such as Air China’s daily flights from Wenzhou in eastern China to Nanning in the south. Others included flights from the carriers’ hubs to smaller regional points, like China Eastern’s flights between its Shanghai Hongqiao hub to Wuzhou in southern China. October’s route expansion is also highest number of launches in recent months, underscoring the rapid domestic recovery reported by each of the three carriers after being impacted by the coronavirus outbreak. For the month, the "Big Three" continued to see growth in domestic traffic, helped by the Golden Week national holidays at the beginning of the month. However, the carriers saw a decline in passenger load factor, as capacity growth outpaced traffic volume International traffic remained at dismal levels, due to global travel restrictions to prevent the spread of the pandemic. China Southern carried 11.8 million domestic passengers in October, a 6% month-on-month increase which was also about 3.3% higher than the same month last year. The Guangzhou-based carrier saw domestic RPKs rise 6.5% month on month, with ASKs gaining 8% compared to September, leading to a 1.15 percentage point decline in domestic load factor. Year-on-year, China Southern saw domestic RPKs rise 2.6%, with ASKs climbing 11.6%. The airline carried around 76,000 international passengers for the month, a 5.8% decrease month-on-month, and a 95% drop year-on-year. As for Air China, it carried 8.37 million domestic passengers in the month, a 3.6% increase month-on-month and a 7.7% increase compared to the same month last year. Month-on-month, domestic RPKs grew 8.3%, while ASKs rose 9.8%, leading to a decline in passenger load factor of 1.1 percentage points to 76.1%. Compared to October 2019, Air China saw domestic RPKs rise 2.6%, with ASKs increasing 13.7%. Air China carried 42,900 international passengers in October, representing a 10% month-on-month rise, but a 97% decline year-on-year. It was the only carrier among the "Big Three" to report an increase in international traffic month-on-month. Meanwhile, China Eastern carried 9.1 million domestic passengers in October, nearly 2% higher month-on-month. Compared to last year, it represented a 2.7% decline. Domestic ASKs rose 3.8% month-on-month, with RPKs increasing 2.6%, leading to a drop of 0.4 percentage points in domestic passenger load factor. Year on year, China Eastern reported a 0.6% increase in RPKs, with ASKs climbing 9.7%. As for its international network, the SkyTeam carrier reported an 8.3% month-on-month fall in passenger numbers, carrying just 26,700 passengers for the month. Year-on-year, passenger numbers plunged 98%.

Source: Cirium

Concerns about a lack of air cargo capacity for the global distribution of Covid-19 vaccines – even those requiring the maintenance of extremely low temperatures during transit – are unfounded, in the view of Cargolux chief executive Richard Forson. The biggest logistical challenge will instead be around the “final mile” distribution of vaccines that require sub-zero storage – something that is out of airlines’ hands, Forson stated during a UK Aviation Club event on 12 November.Recalling IATA’s claim in September that “just providing a single dose to 7.8 billion people would fill 8,000 747 cargo aircraft”, Forson observes that “you’re not going to transport 6 billion doses at one time”. Rather, “there’s going to be a maximum amount of vaccines that can be produced by the pharmaceutical company or companies”. Forson believes, therefore, that “the blockage is not going to be the number of aircraft that is required, because I can tell you all of the passenger aircraft in the world will then be mobilised in order to transport these vaccines”, alongside services offered by dedicated freight operators such as Cargolux. Of new-generation vaccines such as Pfizer-BioNTech’s – which may need to be stored at around -70°C to -80°C until they are within hours of use – Forson notes that transport boxes proposed by the manufacturers will ”ensure that temperatures are not compromised”, while also protecting the aircraft from the effects of ultra-low temperatures. Without those boxes, “I can tell you that there’s no aircraft that can ever get to -80°C”, Forson says. “If it does, it will fall out of the sky.” In addition to new-generation vaccines, “there are also other drug companies that work on the older generation where you don’t have to get to these extreme temperatures, but you get to something like -20°C, which we do on a regular basis”, Forson explains. “So there’s no issue about how we’re going to transport it.” Speaking in September, IATA director general Alexandre de Juniac warned that the airline industry’s ability to play a key role in the distribution of vaccines might be compromised by an air freight capacity crunch. “Safely delivering Covid-19 vaccines will be the mission of the century for the global air cargo industry,” de Juniac stated. “But it won’t happen without careful advance planning.” European carrier Cargolux is one of the largest dedicated freight operators in the world, with 30 Boeing 747 aircraft in its fleet.

Source: Cirium