Dave Reid. You are worrying unnecessarily! I never said it was like a 747 taking off on three engines. I was explaining to the SLF that although some aircraft like 747’s can take off legally with an engine not working a twin engine aircraft would not be allowed to do so. There is a big difference between something being legal and something being feasible. However if you try it in a simulator you will find that a single engine takeoff in a twin jet is quite feasible given a long enough runway and a pilot that understands the relationship between thrust, rudder and rudder fine steering.