Avation PLC (LSE:AVAP) said it has sold the first of three ex-Virgin Australia (ASX:VAH) ATR72-600s to Aegean Airlines and expects to see an improvement in its results for the past half-year as the air travel industry experiences a "gradual recovery" from the COVID-19 pandemic.  The sale of three ATR aircraft to Aegean, in addition to the sale of an Airbus A321 and an Airbus A220 announced since the start of the financial year on 1 July, will increase liquidity and release roughly US$42mln in aggregate net proceeds.