BOEING expects four per cent annual demand growth over the next 20 years increasing demand for its B767 freighter, reports London's Air Cargo News.

The need for more freighters stems from the decline in widebody passenger aircraft in service because of the Covid crisis, resulting in 60 per cent less cargo space in those jets.

Boeing's World Air Cargo Forecast Boeing's provides insight into factors driving demand, such as the pandemic.

Overall, air cargo capacity is down 25 per cent since January. But strong demand has pushed up cargo revenue 16 per cent, with yields jumping 42 per cent, Boeing said.

During the next 20 years, the company anticipates airlines will need 2,430 additional cargo aircraft, among them 930 new widebodies and some 1,500 jets converted from passenger to cargo aircraft.

Boeing vice-president Darren Hulst said he expects strong demand in the coming years for 777Fs and 767Fs. And though the 767F is an aging design - Boeing delivered the first of the type in 1982 - it could remain in production for the foreseeable future, said.

Boeing holds outstanding orders for eighty 767s, including 49 cargo variants, most for UPS and FedEx. The remainder are military variants, according to Boeing's website.

Boeing also produces 747-8Fs (but expects to stop manufacturing that jet in 2022), and speculation abounds about whether Boeing will develop a freighter variant of its 777X.

The forecasted 2,430 new and converted freighters would bring the global air freighter to 3,260 aircraft by 2039, up from 2,010 today, Boeing said.

The Covid-19 pandemic has been a primary short-term driver of freighter demand, as has e-commerce, said Mr Hulst.

"We've seen a growth in the number of aircraft operated as freighters. Aircraft have been taken out of storage, reactivated to fly because of demand for air cargo," he said. "Airlines, freighter operators [and] wet-lease operators have been using their fleets about 20 per cent more than normal."