The International Bomber Command Centre (IBCC) has warned its long-term future is still in doubt despite a celebrity-backed crowdfunding campaign that raised £44,000.
The fundraiser, supported by celebrities including TV presenter Carol Vorderman and actor Colin McFarlane, has temporarily secured the Lincolnshire centre's future but bosses at the site remain concerned over how it will manage post-lockdown.
It is home to the biggest single memorial to Bomber Command and last year lost 90% of its annual income as a result of the pandemic.
People from overseas account for 28% of the IBCC's visitors and with ongoing uncertainty surrounding travel, and the prospect of future events being cancelled, the centre is worried.
Nicky van der Drift, CEO of the IBCC, told Forces News the site is "dependent on what happens with the virus" and how soon it can open.
"Our fear, I suppose, is that we will lose another summer season if we can't open soon," she said.
The IBCC is used as an educational centre for school children and is also a marketing hub for aviation heritage across the county.
Ms van der Drift said the centre brings about £5m a year to the local area.
"The team and I will fight with every breath that we have," she said. "We fought too hard to get here to let it go."
The IBCC's Walls of Names feature commemorates almost 58,000 men and women who lost their lives serving or supporting Bomber Command during the Second World War.
After opening in 2018, it has become one of the most popular visitor attractions in Lincolnshire.