“Short flights are flown at lower altitudes than long-distance flights, hence there is more radiation shielding during short flights because of the greater amount of air above the aircraft,” explained the FAA.
So are passengers in danger? The reality is, for passengers radiation should not be a big concern.
A spokeswoman for the FAA told Express.co.uk: “For the average passenger, the exposure is minimal.”
According to the Health Physics Society (HPS), which specialises in radiation safety, someone would have to spend more than 5,000 hours per year in a plane, or five times as many hours as pilots are allowed to fly, before they would be at risk of radiation.