Airbus plans to deliver all aircraft from its Mobile, Alabama manufacturing facility with sustainable aviation fuel (SAF) on board. "No later than November 2021, all aircraft delivered to customers will be powered by a blend of SAF and conventional jet fuel," the airframer says in a 22 September release. World Energy will provide the USA-sourced SAF to Airbus at the Mobile facility, via global aviation support services provider Signature Flight Support. Airbus delivers A220 and A320 family aircraft to USA-based customers from Mobile. It says the facility has delivered more than 260 aircraft since 2016; 54 in 2021 alone. Airbus Americas’ chairman and chief executive Jeff Knittel states: "SAF is a positive contributor to enhanced sustainability in aviation since it enables up to an 80% reduction of CO2 across the fuel lifecycle. "We are committed to making sustainable fuels an everyday reality with use on an increasingly larger scale, and this announcement is further evidence of that."

More than 97% of United Airlines' US-based workforce has received at least one dose of Covid-19 vaccine, excluding a "small number" of employees who have requested exemption from the carrier's requirement to be fully vaccinated by 31 October. United is also requiring its US-based employees to upload to a company intranet by 27 September proof that they have received at least one vaccine dose. The Chicago-based carrier told employees in a 22 September company memo that it will commence as soon as 28 September a "separation process" for any employee who fails to upload a vaccine record. United had disclosed to its US employees on 6 August that they would be required to receive a Covid-19 vaccine and upload their vaccination records to a company site. "There are now more Covid-related deaths in the US than there were during the 1918 flu pandemic, the deadliest pandemic of the 20th century," United says in the 22 September memo. "While we continue to be encouraged by the outpouring of support and appreciation that we’ve received from employees for the vaccine requirement, we know the decision to get vaccinated was a difficult one for some. But we also know that everyone is safer when everyone is vaccinated. And vaccine requirements work." Frontier Airlines on 6 August announced that employees of the US-based ultra-low-cost-carrier must get vaccinated by 1 October. Frontier employees who will not or cannot get vaccinated will be asked to provide proof of a negative Covid-19 test on a regular basis. Atlanta-based Delta Air Lines on 25 August told its employees that it is adding a $200 surcharge to unvaccinated employees' monthly fees for enrolment in the company healthcare plan, the centre piece of a campaign to persuade its entire workforce to sign up for Covid-19 vaccines. At the time, one-quarter of the airline's employees remained unvaccinated. Nevertheless, Delta, along with US majors American Airlines and Southwest Airlines, has not mandated vaccination for US-based employees.

The airline market is bifurcating between carriers that have been able to recover their operations and generate revenue and those facing a less certain future, it was suggested during an industry conference on 21 September. Paul Da Vall, head of Investec Aviation Equity Fund at Investec Bank, says the "well funded" and "highly liquid" airlines, whether they are back to full service or not, are "well supported and that looks set to continue". "I think the market has priced in their survival," he said during the Airline Economics Growth Frontiers London conference. "I don't think at the start of the pandemic you would have really predicted that yields would have been squeezed as far as they have been for that section of the market, but I think it's fairly overheated, or at least there is a lot of interest in that part of the market on the basis that survival is assured." In contrast, Da Vall says, there is "quite a large part of the market" where things are "very complicated". Geographical differences in the development of the pandemic are having a "big impact" on the prospects of airlines in certain regions. "We're seeing a lot of stress in Asia, which perhaps wasn't necessarily that predictable that Asia would be struggling as it is with borders shut, real tight restrictions on movement of people," he says. "And obviously we're seeing now some cases in Asia that are serious cause for concern. I do think there will be further stress in that market." Fellow panellist Patrick den Elzen, managing director of Arena Aviation Capital, says there are airlines "that will make it", as well as a "large group of airlines where the jury is still out". The latter group, he says, are being kept alive on state support and other sources of funding, unlike their more successful peers who "can actually generate revenue the old-fashioned way by flying passengers around". Den Elzen expects these weaker carriers will probably "be very close to getting into prolonged trouble if this industry is not able to come back to what it was before Covid within the next, let's say, 12 to 24 months". "So I think we are certainly not there yet," he says, "and there is going to be, I'm afraid, a lot of problematic cases for a prolonged period of time." Da Vall adds: "The equilibrium that us as managers want to be able to have for our investors won't return for some time."