A line of thunderstorms associated with a cold front and topping out above 52,000 ft was moving east over southern Ontario, Canada, the afternoon of Sept. 5, 2014. An air traffic control ground hold due to the severe weather was in effect at the airport in Grand Rapids, Michigan, U.S., providing time for the flight crew of an Embraer 145LR to take another look at the convective activity on their cellphone weather apps and plot a viable route to their destination: Newark (New Jersey, U.S.) Liberty International Airport.
“The flight crew decided that the line of thunderstorms appeared to be fragmented enough, with sufficient openings, to allow them to deviate from their planned route around the weather system,” said the report by the Transportation Safety Board of Canada (TSB).
The aircraft, operated as ExpressJet Airlines Flight 4538, departed from Grand Rapids at 1845 local time carrying 26 passengers, a flight attendant and the two pilots.
The captain was the pilot flying…
