Balpa has issued a desperate plea to the UK government in a bid to stop the winding down of furlough support at the end of September.
The pilots union said that with major global restrictions on air travel still in place "now is not the time to remove the furlough lifeline".
According to analysis of HMRC, CJRS and PAYE figures carried out by Balpa, air transport tops the list of industry groups with the highest rates of jobs being put on furlough.
As of 31 July, 51% of air transport workers were reportedly on furlough.
BALPA acting general secretary, Martin Chalk, said the statistics show that air transport is still "right in the grip" of the Covid crisis.
“UK government and global restrictions mean that while other sectors have been able to get up and running, aviation is still essentially in lockdown," he added.
"The workforce is the engine of aviation. However, more than half of the air transport workforce is still on furlough despite Chancellor Rishi Sunak’s positive spin on today’s wider figures. The industry is ready to serve the country – but stopping furlough will shut down our engines before we are cleared for take off."
Chalk called on the central authority to support the sector or "jobs will be at risk", claiming the industry will not be able to replace skilled workers who lose their jobs due to the removal of financial support.
"We need to see a simplified system of travel restrictions that passengers can understand and that give safe travel clearance to get the industry moving again," Chalk continued.
"We know people want to travel, and across Europe we are seeing signs of a recovery… but the UK government isn’t backing our industry and we can see clearly that we are losing our place as a world leader in aviation."