Airlines and airports are recommending a layered approach to temporary safety measures as air travel restarts, warning that no single measure can mitigate all of the risks during the pandemic, according to a briefing document seen by Reuters.

The plan laid out by the International Air Transport Association (IATA) and Airports Council International to reassure governments it is safe for the public to fly includes contact tracing, temperature screening, social distancing, extra cleaning and wearing masks.

“Successfully restarting air passenger travel while restoring confidence in the safety of air travel are vital pre-requisites to enabling the global economy to recover from COVID-19,” the groups said in the document, which has not been made public. “In normal times, aviation delivers $2.7 trillion in global GDP contribution.”

IATA and ACI declined to comment specifically on the document but both said they were working with industry partners on a consistent global approach.

Many airlines and airports around the world are implementing measures such as requiring masks and leaving middle seats empty, in some cases due to government requirements.

The industry supports reliable COVID-19 testing, but at the moment virus and antibody tests are not a viable solution at airports and there is no confirmed evidence yet that antibodies confer immunity, according to the IATA and ACI document.

Should health-screening measures be necessary, it should be done long before passengers arrive at the airport, the document said.

Temperature checks on airport entry and exit are not likely to prove 100% effective because they may miss mild cases and those in the incubation period, but the measures could play a useful role in reassuring passengers and deter travel in the case of suspected infections, according to IATA and ACI.

Social and physical distancing should be limited to the initial restart phase because the measures will cap airport and aircraft capacity once travel demand grows, the document said.

Security and health screenings should be mutually recognised when possible so that transfer passengers do not need to line up and be re-screened, leading to additional human contact, IATA and ACI said.

“There is currently no single measure that could mitigate all the risks of restarting air travel,” the document concluded.

“However, we believe that an effective implementation on an outcome basis and layered approach, of the above-mentioned range of measures that are already possible, represents the most effective way of balancing risk mitigation with the need to unlock economies and to enable travel in the immediate term.”