For large transport aircraft the stabilizing moment necessary for recovery comes from the fin with little requirement for rudder deflection. These aircraft do not have a requirement to withstand near-full rudder deflections in these circumstances[16] because the structural weight required to prevent structural failure would make them commercially unviable. Loss of the complete fin and rudder assembly occurred on American Airlines Flight 587 when the pilots used full rudder deflections while following in the wake of a very large jet.[17]