The instantaneous rate at which susceptible contacts are infected depends on the time since infection, and is described by an infectiousness function ( [9] , page 45). We use a peaked infectiousness function, motivated by viral shedding and household transmission data [2] , which has a serial interval of 2.6 days. The basic reproduction number (R 0 ), namely the reproduction number when there is no intervention in place and every contacted individual is susceptible, is given by the area under the infectiousness function. However, our concern is with the effective reproduction number R that holds when various interventions are in place. We obtain any R by simply multiplying the infectiousness function by the appropriate constant (to make the area under the curve equal to R). This keeps the serial interval the same. In the absence of suitable data we assume for most scenarios that the aircrafts ventilation and filtration systems are functioning properly, and that infected travelers transmit the infection at the same rate during a flight as they would while mixing in the community. We examine the sensitivity of this assumption by increasing the inflight transmission by as much as 10-fold (as could potentially happen if air-circulation and filtration systems malfunction, e.g. see [10] ). The in-flight transmission rate is set to zero under the optimistic scenario that all travelers wear 100% effective masks during transit. In terms of a sensitivity analysis this illustrates what would be achievable in a best-case scenario. The number of offspring that an infected traveler infects during a flight is a random variable, taken to have a Poisson distribution with a mean equal to the area under the infectiousness function over to the flight duration.