This Technical Note, which is an update to a PRC Technical Note published in 2008, concludes that Vertical flight efficiency has been quite stable over the past few years but the COVID pandemic has had its impact on VFE as well. The report highlights the results in 2020 and the change with respect to 2019.
In addition, the results during the COVID period are highlighted. Overall, vertical flight efficiency during descent has improved while it has remained quite the same for climbs. In the en-route phase, vertical flight efficiency has improved for most airport pairs. Also, the most inefficient airport pairs in 2019 have seen an improvement in 2020. However, the inefficiency on these airport pairs stayed pretty high.
Read more in the full document available for download below.